NCM 212 Pharmacology Unit 1 PDF

INTRODUCTION TO PHARMACOLOGY Pharmacology Illicit drug - is the study of the biological effects of chemicals or drugs. - also called street drug are those sold illegally. Definitions Pharmacopeias: -...

INTRODUCTION TO PHARMACOLOGY Pharmacology Illicit drug - is the study of the biological effects of chemicals or drugs. - also called street drug are those sold illegally. Definitions Pharmacopeias: - are the total of all authorized drugs available within the country. Medication - is a substance administered for diagnosis, cure, treatment, mitigation or prevention. Prescription Drug Names - the written direction for the preparation and the administration of the drug. 1) Chemical name Therapeutic effect - Describes the drug’s chemical composition and molecular - is the primary effect intended that is the reason the drug is structure prescribed such as morphine sulfate is analgesia. ex: (+/-)-2-(p-isobutylphenyl) propionic acid Side effect - secondary effect of the drug is one that unintended, side 2) Generic name (nonproprietary name) effects are usually predictable and may be either harmless. - Name given by the United States Adopted Name Council Drug toxicity Ex: ibuprofen - deleterious effect of the drug on an organism or tissue, result from overdose or external use. 3) Trade name (proprietary name) Drug allergy - The drug has a registered trademark; use of the name - is immunological reaction to a drug restricted by the drug’s patent owner (usually the Drug interaction manufacturer) - occur when administration of one drug before or after alter ex: Motrin®, Advil® effect of one or both drug. Drug misuse Drug - Is the improper use of common medications in way that lead - any chemical that affects the physiologic processes of to acute and chronic toxicity for example laxative, antacid and living organisms. vitamins. - natural product, or pharmaceutical preparation intended Drug abuse for administration to a human to diagnose or treat a - is an inappropriate intake of substance either continually or disease. periodically. Drug dependence Sources of drugs - is a person's reliance on or need to take drug or substance 1. Plant or plant parts - which has been used since there are two type of dependence: prehistoric times Physiological dependence - is due to biochemical changes in 2. Animal products – like insulin, growth hormones, thyroid the body tissue these tissue , come to require substance for drugs normal function. 3. Inorganic compounds – Aluminum, flouride, iron Psychological dependence - is emotional reliance on a drug to 4. Synthetic sources – scientist used genetic engineering maintain a since of wellbeing accompanied feeling of need. to alter bacteria to produce chemicals that are therapeutic Drug habituation and effective like vaccines - denotes a mild form of psychological dependence. Transcribed by: Shania Barbra Ruaya  PHARMACOKINETICS AND PHARMACODYNAMICS Common functions of the nurse Administering medications supervising medication self-administration assisting other health personnel with the administration of medications Areas of Pharmacology 1) Pharmaceutics - The study of how various drug forms influence pharmacokinetic and pharmacodynamic activities. 2) Pharmacokinetics The ADME Process - The study of what the body does to the drug molecules. 4 Phases: Absorption - when a drug is released from its formulation/ – Absorption – Distribution – Metabolism – Excretion admin site and enters the bloodstream Distribution- the movement of a drug once in the 3) Pharmacodynamics bloodstream - The study of what the drug does to the body. Metabolism - the body using the drug and giving off a – the mechanism of drug actions in living tissues byproduct. Excretion - the getting red of the byproduct. 4) Pharmacotherapeutics - The use of drugs and the clinical indications for drugs to Absorption prevent and treat diseases. A drug to produce a pharmacologic effect, it must be 5) Pharmacognosy absorbed or transported from its site of administration (GI - The study of natural (plant and animal) drug sources. tract, muscle, skin) into the bloodstream -formerly called materia medica (medicinal materials) and is concerned with botanical or zoologic origin. The rate at which drugs are absorbed determines the onset of effect. In turn, the amount of drug absorbed determines the Pharmacokinetics intensity of effects Both drug-related & patient-related factors influence Phases of drug activity drug absorption First pass effect Pharmaceutical The metabolism of a drug and its passage from the liver phase into the circulation – A drug given via the oral route may be extensively metabolized by the liver before reaching the systemic Pharmacokinetic circulation (high first-pass effect) phase – The same drug—given IV—bypasses the liver, preventing the first-pass effect from taking place, and more drug reaches the circulation Pharmacodynamic phase Transcribed by: Shania Barbra Ruaya  Distribution - It refers to the transportation of drug via the bloodstream to its site of action. For a drug to achieve its therapeutic effect, it must proceed to the part of the body or tissue with which it will react. At this point some drugs are eliminated in the liver and kidney Factors that affect the absorption of the medication in the stomach: Acidity of the stomach The presence or absence of food or fluid Age of the patient Presence of other types of medication Drugs administered sublingually or in buccal mucosa, they are absorbed in the highly vascularized (large blood supply) tissue like under the tongue. Bypassed the liver Absorbed rapidly in the bloodstream and delivered at the site of action Parenteral Metabolism – Is the general term meaning any route other than the - Biotransformation in the liver stomach, most commonly it refers to injection like - It involves biochemical alteration of the drug to inactive subcutaneous, intradermal and intramuscular metabolite, a more soluble compound or to a more potent – Advantage of bypassing the first pass effect active metabolite – Absorbed at the site of injection Other metabolic tissue: skeletal muscle, kidney, lungs, – Intravenous intestinal mucosa Delivers drug directly into the bloodstream Fastest absorption Delayed drug metabolism results in: Accumulation of drugs Topical drugs Prolonged action of the drugs – Absorbed locally and effect is non-systemic Stimulating drug metabolism causes: Inhaled drugs will be transported and absorbed in the air Diminished pharmacologic effects sacs or alveoli Transcribed by: Shania Barbra Ruaya Excretion Once the drug hits its “site of action” it can modify the - Elimination of drug in the body rate at which a cell or tissue functions. Whether active or inactive, drugs must eventually be removed from the body Mechanism of Action Kidney ( main organ) 1. Receptor Interaction Other organ of excretion: the bowel and liver Drug structure is essential Other routes of excretion: through sweat and saliva Involves the selective joining of drug molecule with a reactive site on the cell surface that elicits a biological effect Receptor is the reactive site on a cell or tissue Once the substance binds to and interacts with the receptor, a pharmacologic response is produced Pharmacodynamics - Study of the mechanism of drug actions in living tissue What a drug does to the body- relates to the site of drug Affinity- used to describe the strength of the drug’s action binding to receptors The site of drug action is the specific cell, tissue, or organ The drug with the best “fit” or affinity will elicit the best where the drug works response 3 Principles about Drug Action ' 1. Drugs do not create new function or response but modify or alter existing physiologic activity within the body; 2. Drugs interact with the body in several different ways. No drug has a single action 3. Drug effects are determined by the drug’s interaction with the body. Pharmacodynamics Drugs -induced alterations to normal physiologic function Positive change Therapeutic effect Goal of therapy Drug Action Antagonist-drug binds to receptor-no response-prevents < Mechanism of Action binding of agonists (Alpha & Beta Blockers) - Ways in which a drug can produce a therapeutic effect Competitive Antagonist- act with receptor sites to block The effects that a particular drug has depends on the cells normal stimulation producing no effect or organ targeted by the drug. Noncompetitive Antagonist – prevent reaction of another chemical with different receptor site on that cell Transcribed by: Shania Barbra Ruaya Parameters of Drug Action Toxic Effects of Drugs Onset of Action- interval between time drug is administered & first sign of its effect. Adverse Effects Duration of Action- length of time the drug exerts -Predictable or unpredictable pharmacologic effect. - Excessive pharmacologic effects Peak Action – drug reaches its highest blood/plasma > most predictable and are often the easiest to prevent or concentration counteract > May be unpleasant or even dangerous 2. Enzyme Interaction Enzymes- are substances that catalyze nearly Occur for many reasons, including the following: every biochemical reaction in a cell. The drug may have other effects on the body besides Drugs can interact with enzyme systems to alter a response the therapeutic effect Inhibits action of enzymes-enzyme is “fooled” into binding to The patient is sensitive to the drug given drug instead of target cell The drug’s action on the body causes other responses Protects target cell from enzyme’s action (ACE Inhibitors) that are undesirable or unpleasant The patient is taking too much or too little of the drug, 3. Non-Specific Interaction leading to adverse effects Not involving a receptor site or alteration in enzyme function Main site of action is cell membrane or cellular process Primary actions Drugs will physically interfere or chemically alter cell One of the most common occurrences in drug therapy is process the development of adverse effects from simple overdose Final product is altered causing defect or cell death - can be extensions of the desired effect Cancer drugs, Antibiotics Secondary actions Half - Life - are effects that the drug causes in the body that are - A measure of the time required for elimination. not related to the therapeutic effect - Is determined by an individual’s ability to metabolize and In addition to the desired pharmacological effect excrete a particular drug - When the half-life of the drug is known, dosages and Hypersensitivity frequency of administration can be calculated. Some patients are excessively responsive to either the primary or the secondary effects of a drug For example: if a patient is given 100 mg of a drug that has a - It may result from a pathological or underlying condition half-life of 12 hours, it will show like this: Hypersensitivity Reactions Gell and Coombs Classification System Type I reactions are immediate hypersensitivity reactions that are mediated by immunoglobulin E (IgE) antibodies. Eg: urticaria (hives), atopic dermatitis, anaphylactic shock Type II reactions are cytolytic reactions that involve The nurse is giving a medication that has a high first-pass complement are mediated by immunoglobulins G and M (IgG effect. The physician has changed the route from IV to PO. and IgM) The nurse expects the oral dose to be: Eg: hemolytic anemia,thrombocytopenia, and drug-induced 1.Higher because of the first-pass effect. lupus erythematosus 2.Lower because of the first-pass effect. 3.The same as the IV dose. 4. Unchanged. Transcribed by: Shania Barbra Ruaya  Type III reactions are mediated by immune complexes. The Interventions deposition of antigen- antibody complexes in vascular In mild cases, or when the benefit of the drug outweighs endothelium leads to inflammation, lymphadenopathy, and fever the discomfort of the skin lesion, provide frequent skin (serum sickness) care; instruct the patient to avoid rubbing, wearing tight Eg: severe skin rash seen in patients with a life-threatening or rough clothing, and using harsh soap or perfumed form of drug-induced immune vasculitis that is known as lotions Stevens- Johnson syndrome Administer anti-histamines as needed Type IV reactions are delayed hypersensitivity reactions that In severe cases, discontinue the drug are mediated by sensitized lymphocytes. Notify the prescriber Eg: ampicillin-induced skin rash that occurs in patients with Application of topical corticosteroids or emollient are viral mononucleosis frequently used Drug Allergy Stomatitis - Occurs when the body forms antibodies to a particular drug, - Inflammation of the mucous membranes, can occur causing an immune response when the person is re-exposed to because of a direct toxic reaction to the drug or because the drug. the drug deposits in the end capillaries in the mucous Four main classifications: membranes, leading to inflammation. a) Anaphylactic reaction- this allergy involves an antibody that Eg: Antineoplastic drugs reacts with specific sites in the body to cause the release of Assessment: chemicals, including histamine that produce immediate > It includes swollen gums, inflamed gums (gingivitis) and reactions(mucous membrane swelling & constricting bronchi) swollen and red tongue (glossitis) that can lead to respiratory distress and even respiratory Interventions arrest. Provide frequent mouth care with a non irritating solution b) Cytotoxic reaction – this allergy involves antibodies that Offer nutrition evaluation circulate in the blood and attack antigens (the drug) on cell Development of tolerated diet sites, causing death of that cell. This reaction is not immediate but may be seen over a few days. Superinfection c) Serum Sickness reaction – this allergy involves antibodies One of the body’s protective mechanisms is provided by that circulate in the blood and cause damage to various the wide variety of bacteria that live within or on the tissues by depositing in blood vessels. This reaction may occur surface of the body. up to a 1 week or more after exposure to the drug - This bacterial growth is called the normal flora d) Delayed allergic reaction – this reaction occurs several Several kinds of drugs especially antibiotics destroy the hours after exposure and involves antibodies that are bound to normal flora, leading to development of superinfection specific white blood cells. Assessment Symptoms can include fever, diarrhea, black or hairy tongue, inflamed and swollen tongue(glossitis), mucous Drug-induced Tissue and Organ Damage membrane lesions and vaginal discharge with or without itching Dermatological Reactions Interventions - Are adverse reactions involving the skin a. Provide supportive measures like frequent mouth care, - It range from a simple rash to potentially fatal exfoliative skin care, access to bathroom facilities, small and frequent dermatitis meals Rashes, Hives b. Administer antifungal therapy as appropriate - rash, scaling, fever, enlarged lymph nodes, enlarged liver and the potentially fatal erythema multiforme exudativum or known as Stevens-Johnson syndrome. Transcribed by: Shania Barbra Ruaya Blood Dyscrasia Assessment: - is bone marrow suppression caused by drug effects elevated blood urea nitrogen (BUN), elevated creatinine Assessment concentration, decreased hematocrit, electrolyte imbalances, fever, chill, sore throat, weakness, back pain, dark urine, fatigue, malaise, edema, irritability and skin rash agranulocytosis, anemia, thrombocytopenia(low platelet), Interventions: leukopenia (low WBC) or a combination of these (pancytopenia) Notify the prescriber - most serious is aplastic anemia Discontinue the drug as needed Interventions Offer supportive measures ( diet & fluid restrictions, skin Monitor blood counts care, electrolyte therapy, rest) Provide supportive measures (rest, protection from exposure In severe cases, dialysis may be required for survival to infections, injury, or bleeding) In severe cases, discontinue the drug or stop administration Other organ toxicities until the bone marrow recovers to safe level, but may have serious consequences before toxicity can be detected Pulmonary toxicity occurs through a variety of mechanisms. Some drugs cause respiratory depression via their effects Toxicity on the brain stem respiratory centers. - Introducing chemicals into the body can sometimes affect Relatively few drugs produce cardiotoxicity. Some may the body in a very noxious or toxic way cause skeletal muscle damage evidenced by muscle pain and sometimes leading to rhabdomyolysis Liver injury (Hepatotoxicity) Poisoning Cholestatic hepatotoxicity is often caused by a hypersensitivity - Occurs when an overdose of a drug damages multiple mechanism producing inflammation and stasis of the biliary body systems, leading to the potential for fatal reactions system Emergency and life support measures often are needed in Hepatocellular toxicity is sometimes caused by a toxic drug severe cases metabolite Assessment: Skin rashes of all varieties fever, malaise, nausea and vomiting, jaundice, change in color - These can range from a simple rash to potentially fatal of urine or stools, abdominal pain or colic, elevated liver exfoliative dermatitis. Adverse reactions involve the skin enzymes (serum transaminase level) because many drugs can deposit there or cause direct Interventions irritation to the tissue. Discontinue the drug and notify the prescriber - It includes macular, papular, maculopapular & urticarial Offer supportive measures ( small, frequent meals, skin care, rashes, and potentially fatal erythema multiforme cool environment, rest periods) exudativum (Stevens- Johnson syndrome) may be produced by drug hypersensitivity reactions. Renal injury (Nephrotoxicity) - Classified according to site and mechanism and include Idiosyncratic reactions interstitial nephritis, renal tubular necrosis and crystalluria(the - Unexpected drug reactions caused by a genetically precipitation of insoluble drug in the renal tubules) determined susceptibility results to: extreme sensitivity to a low dose extreme insensitivity to a Bladder toxicity high dose unpredictable or unexplainable symptoms - is less common than renal toxicity, but it may occur as an - results in paradoxical reactions (opposite of desired) adverse effect of a few drugs. Eg: a sedative is given for insomnia, but instead keeps the One example is cyclophosphanamide, an antineoplastic drug patient awake whose metabolite causes hemorrhagic cystitis Transcribed by: Shania Barbra Ruaya Drug interactions 1) Additive effect - 2 drugs with similar actions are taken for a doubled effect (1+1 =2) Ibuprofen + paracetamol = added analgesic effect 2) Synergistic - Combined effect of 2 drugs is greater than sum of the effect or each drug given alone (1+1=3) Aspirin + codeine = greater analgesic effect 3) Potentiation - A drug that has no effect enhances the effect of a 2nd drug (0 +1=2) 4) Antagonistic - One drug inhibits the effect of another drug (1+1 = 0) - Tetracycline +antacid =decreased absorption of tetracycline DRUG APPROVAL PROCESS International Drug Standards Regulations In 1962, this act was again amended by the Kefauver- Harris Amendment. It added the requirement that both Federal control for the protection of consumers who used prescription and nonprescription drugs be shown to be drugs did not exist until the beginning of the twentieth effective as well as safe. century. After a number of catastrophic incidents in which death resulted from the use of adulterated drugs, the first This was followed in 1970 by the Comprehensive Drug federal statute controlling the manufacture of drugs was Abuse Prevention and Control Act also known as the passed - the Food and Drug Act of 1906. It required that all Controlled substance Act of 1970 which further classified drugs marketed in the United States meet minimal standards of drugs according to their potential for physical or strength, purity and quality. psychological dependence and abuse. It also regulated the manufacture and distribution of drugs considered capable of causing dependence. The act also established the U.S. Pharmacopoeia (USP) and the National Formulatory( NF) as the official legal standards for drugs in the United States. Federal Food, Drug and As a result of these federal statutes, all drugs may be Cosmetic Act of 1938 added the requirement that a drug be classified into Four Categories: shown to be safe before it could be distributed in interstate 1. Prescription or legend drugs commerce. 2. Nonprescription or over the counter ( OTC) drugs 3. Investigational drugs 4. Illicit or street drugs An amendment to this act known as the Durham- Humphrey Amendment, was enacted in 1952. It required that certain Prescription drugs drugs be classified as legend drugs and that they be labelled - Before such drugs can be marketed in the United States, with the legend " Caution- Federal law prohibits dispensing the manufacturer must file a New Drug Application with without prescription." It also specified that all other drugs the FDA. approved for use be considered nonprescription drugs. These - This action must include a detailed description of the could be sold directly to the consumer without the need for a drug, it's toxicity and the results of all experimental prescription. clinical trials of the drug in clients. Transcribed by: Shania Barbra Ruaya - May be prescribed by health care providers, dentists, Animal testing is important because unique biological veterinarians or other legally authorized health practitioners differences can cause very different reactions to the as part of their specific practice. chemical. At the end of the preclinical trials, some chemicals are Nonprescription Drugs discarded for the ff reasons: - Drugs that may be legally acquired by the client without a Chemicals lacks therapeutic activity when used with living prescription are known as nonprescription or OTC drugs. animals - Such agents are considered to be relatively safe for the lay b. Chemicals is too toxic Chemicals are highly teratogenic person to use when taken according to directions provided by the manufacturer and when given to treat conditions for which 2. Phase I Studies they are intended. - Uses human volunteers to test the drugs - These studies are more tightly controlled than preclinical Investigational Drugs trials and are performed by specially trained clinical - To fulfill the requirements of the FDA, a manufacturer that investigators seeks to market a new drug must perform a wide array of - The volunteers are fully informed of possible risks and animal studies and carry out clinical testing of the drug in may be paid for their participation. human subjects. - Usually the volunteers are healthy, young men - To accomplish this, the manufacturer must file a "Notice of Investigators in Phase I studies scrutinize the drugs Claimed Investigational Exemption for a New Drug (IND) with being tested for effects in humans the FDA. Many chemicals are dropped for the ff reasons - Clinical studies performed on human subjects prior to the a. They lack therapeutic effect in humans marketing of a drug are usually divided into four phases. b. They cause unacceptable adverse effects c. They are highly teratogenic Illicit Drugs d. They are too toxic - or" street drugs are those that are used and distributed > Some chemicals move to the next stage of testing despite illegally. undesirable effects. They may be : > Like the hypertensive drug : Minoxidil (Loniten) was found 1. Drugs that are not legal for sale under any circumstances in to effectively treat malignant hypertension but it caused the United States Eg. Heroine unusual hair growth on the palms and other body areas 2. Drugs that may be sold legally under certain circumstances (e.g. With a prescription) but that have been manufactured 3. Phase II Studies illegally or diverted or stolen from normal channels of - Allows clinical investigators to try out the drug in distribution. Illicit drugs usually are used for non medical patients who have the disease that the drug is designed to purposes, generally to alter mood or feeling. treat. - Patients are told about the possible benefits of the drug The Drug Enforcement Administration and the Orphan Drug and are invited to participate in the study Acts (1983) - Various sites across the country - are drugs that have been discovered but are not financially May be removed from further investigation for the viable and therefore have not been "adopted" by any drug following reasons: company. a. It is less effective than anticipated b. It is too toxic when used with patients Stages of Drug Development c. It produces unacceptable adverse effects d. Has low benefit to risk ration – therapeutic benefit it 1.Pre-Clinical Trials provides does not outweigh the risk of potential - Chemicals that may have therapeutic value are tested on laboratory animals for two main purposes: a. To determine whether they have the presumed effects in living tissue b. To evaluate any adverse effects Transcribed by: Shania Barbra Ruaya 4. Phase III Studies Schedule I - Involves use of the drug in a vast clinical market -Drugs in Schedule I have a high potential for abuse and - Prescribers are informed of all the known reactions to the no accepted medical use in the United States drug and precautions required for its safe use. Eg. Heroin, LSD, Ecstasy - Patients will be observe very closely and monitored Schedule II - Asked to make journals and record any symptoms they - Drugs in Schedule II also have a high potential for experience abuse, but do have a currently accepted medical use in the > Drugs that finish Phase III studies are evaluated by the United States. It has been determined that abuse of a FDA, which relies on committees of experts familiar with the drug included in this schedule may lead to a severe specialty area in which drugs will be used. psychological or physical dependence. > Only those drugs that receive FDA committee approval may Eg. Meperidine, morphine, cocaine, oxycodone be marketed. Schedule III - Schedule III drugs have accepted medical uses in the 5. Phase IV studies united States, but they have a lower potential for abuse - After a drug is approved for marketing, it enters a phase of than drugs in Schedules I and II. continual evaluation. Eg. Acetaminophen with codeine, hydrocodone - Prescribers are obligated to report to the FDA any untoward Schedule IV or unexpected adverse effects associated with drugs - Schedule IV drugs have a low potential for abuse relative to Schedule III drugs. Abuse of Schedule IV drugs may SAFETY DURING PREGNANCY - PREGNANCY CATEGORIES lead to limited physical or psychological dependence as compared with Schedule III drugs. Category A Eg. Librium, Valium - Adequate studies in pregnant women have not demonstrated Schedule V a risk to the fetus in the first trimester of pregnancy, there is - Schedule V drugs have the lowest abuse potential of the no evidence of risk in later trimesters controlled substances. They consist of preparations Category B containing limited quantities of certain narcotic drugs - Animal studies have not demonstrated a risk to the fetus but generally used for antitussive and antidiarrheal properties. there are no adequate studies in pregnant women or animal Eg. Lomotil, Robitussin studies Category C Strengthening the Support Mechanism for the Philippine - Animal studies have shown an adverse effect on the fetus Drug Enforcement Agency but there are no adequate studies in humans; the benefits from the use of the drug in pregnant women may be WHEREAS, by virtue of the Comprehensive Dangerous acceptable despite its potential risk Drugs Act of 2002 ( Republic Act (R.A.) No. 9165), the Category D Philippine Drug Enforcement Agency (PDEA) was created for - There is evidence of human fetal risk, but the potential the efficient and effective law enforcement of all the benefits from the use of the drug in pregnant women may be provisions on dangerous drugs and/or precursors and acceptable despite its potential risk essential chemicals as provided in R.A. No.9165; Category X - Studies in animals or humans demonstrate fetal abnormalities WHEREAS, pursuant to R.A. No. 9165, the Dangerous or adverse reaction; reports indicate evidence of fetal risk Drugs Board (DDB) is the policy-making and strategy- formulating body in the planning and formulation of policies The Controlled Substances Act of 1970 and programs on drug prevention and control. - regulates the manufacturing, distribution and dispensing of drugs that are known to have abuse potential. WHEREAS, R.A. No. 9165 provides for the abolition of the drug enforcement units of the Philippines National Police (PNP), the National Bureau of Investigation and Bureau of Customs; Transcribed by: Shania Barbra Ruaya Generics Act of 1988 (Republic Act No. 6675) - This Act, consisting of 15 sections, declares the policy to promote, require and ensure the production of adequate supply, use and acceptance of drugs (including for animal use) identified by their generic names. Its objectives are: to promote, encourage and require the use of generic terminology in the importation, manufacture, distribution, marketing, advertising and promotion, prescription and dispensing of drugs; to ensure the adequate supply of drugs with generic names at the lowest possible. NURSING PROCESS IN PHARMACOLOGY INDIVIDUAL VARIATION OF PHARMACOLOGICAL Time of administration RESPONSE - the time of day or month that a drug is administered has been shown to affect the pharmacological response of While an understanding of the fundamental scientific clients to specific drugs. principles discussed this far is essential in understanding how Example: corticosteroids often are more effective if given drugs exert their effects, it should be noted that considerable in the morning than at night variations may occur in the response of any two individuals to the same drug and dosage regimen. Tolerance - considerable variation exists in the ability of different FACTORS THAT HAVE BEEN SHOWN TO CONTRIBUTE TO clients to become tolerant to the effects of certain drugs, INDIVIDUAL VARIATION OF DRUG RESPONSE particularly narcotic analgesics and other CNS depressants. This may account for the dramatic differences in the Age dosage of a particular drug required to elicit a given level - those clients who are at age extremes, the very young and of pharmacological response in clients very old, often exhibit great variations in drug absorption, distribution, bio transformation and elimination. Environmental factors - exposure to very hot or cold environmental temperatures Gender may influence an individual's response to drug therapy. - male and female individuals have different body compositions. - The proportion of fat to lean body mass may influence the Herbal Therapies and Interaction action as well as the distribution of drugs through the body. Herbs Body weight Herbal medicine has been used since prehistoric times - increased body weight may necessitate the use of higher and is used today by up to 80% of the worlds' population. drug doses because the dose required to reach equivalent - It involves the use of natural plant substances to prevent levels of a drug in body tissues. and treat disease. The latter part of the 1990’s and into the twenty-first Disease states century has seen an increased use of herbal supplements - underlying disease states may affect an individual's response by people believing these substances can prevent and cure to a drug by modifying factors such as absorption, distribution, disease. bio transformation and elimination. As a result, in 1998 the World Health Organization Genetic factors (WHO) first published Guidelines for the Appropriate Use of - individual variation in response to the effects of drugs may Herbal Medicines occur because of genetic differences between two individuals. Transcribed by: Shania Barbra Ruaya  Historically, herbal medicines has been associated with the The American Society of Anesthesiologists recommends Chinese and frequently is used in conjunction with that clients discontinue their use of herbals a minimum of acupuncture, but associating all herbals with Chinese medicine 2 to 3 weeks prior to surgery due to the numerous risks narrows the user's focus. associated with surgery and anesthesiology in the presence Currently, herbals are sold in nutrition stores, major drug of these products. chains, as well as discount retail stores wherever vitamins are sold. Drug therapy for pediatric clients Of primary concern to health care professionals is that herbals are not regulated by the FDA, and thus their safety Providing safe and effective pediatric drug therapy and efficacy have not been reliably established. represents a great challenge to the health professional. Herbal treatment claims range from the treatment and During the period from birth through adolescence, the prevention of heart disease to adjuncts to cancer prevention pediatric client is continually undergoing dramatic changes and therapy. in physical growth, psychosocial development and sensitivity Some of the herbs and their uses are familiar to many to drugs. people, such as aloe Vera, garlic, ginseng, St. John's wort, gingko, echinacea and saw palmetto. Pharmacokinetic differences in the pediatric client Nursing implications Absorption Because of the increased use of herbal medicine in our - reduced gastric acidity because the gastric acid- society, nurses need to be sure to address this matter during producing cells in the stomach are immature until the age the assessment of all clients. of 3. - As a result, medications such as enteric-coated tablets, Two important facts health care professionals need to which are dependent on a low pH to break down, may pass remember are: through the digestive tract unchanged. 1. Herbals are not regulated by the FDA. - Gastric emptying is slower, because peristalsisis irregular. 2. Herbals, like drugs, are chemicals, and consequently, - Topical absorption is faster because of thinner skin and chemically have an influence on the body. disproportionate skin surface area Nurses need to be familiar with herbals in common use, and Because IV medication bypass the absorption step, the should ask clients if they use herbals, what herbals they use action of drugs given using this route is more predictable and how often, and assess the client's knowledge of why they are taking these supplements. Distribution The nurse also needs to assess the clients for the presence Total body water ( TBW) content is much greater: of potential adverse effects associated with the use with the between 70% and 85% in infants. Percentages of use of the specific herbal medicines. circulating water are higher in the child, and therefore Reporting the information received to the health care children require higher doses per kilogram of weight of provider is an important nursing action that can influence the water-soluble medications than do older clients. pharmacotherapeutics of medical treatment. The blood- brain barrier is immature, leading more drugs to enter the brain. Another nursing concern is the interaction between herbal and prescription medications, thus reporting the information Metabolism received to the health care provider is an important nursing The levels of enzymes are decreased because of the implication. immaturity of the liver. Herbal supplements can enhance or decrease the effects of Children ( age 2-6 years) have higher metabolic rates and certain drugs, thus the individual thus may require higher levels of medication, especially should be instructed not to use these herbal supplements older children, whose livers have established microsomal when taking the medications. enzymes. Transcribed by: Shania Barbra Ruaya Elimination 6. Obtain information from the caregivers about family and Glomerular filtration rate is approximately 30-50% less than personal history of allergy. an adult because of immaturity of the kidneys 7. Consent must be obtained from caregivers before Tubular secretion and reabsorption are decreased, due to medication administration renal immaturity 8. Avoid mixing medications into essential foods or milk. As Perfusion to the kidneys is decreased this may cause the child to avoid these foods. Urine pH is lower in an infant, as well as the capacity to 9. Never tell children the medication is candy or deceive concentrate urine, resulting in medications circulating longer them about what they are taking. and having the potential of reaching toxic levels. After the first few weeks of life, the kidneys have the acidifying ability Poisoning of the adult. - is one of the leading causes of injury and the fourth highest cause of death in children between the ages of 1 Classification of Pediatric Clients year and 5 years. The most common medication ingested is acetaminophen. About 90% of all poisonings in children take place in the home, and most are preventable. Poisoning Prevention Prevention is the preferred means of reducing accidental poisonings in children. The nurse can play a major role in making parents aware of the ways they can protect their children. Nurses in institutional and community settings should provide instruction and guidance for parents and child caregivers. One successful approach in reducing the incidence of Determining Pediatric Dosages childhood poisoning is conducting educational programs that Establishing an appropriate drug dosage for a pediatric client teach the child to stay away from hazardous locations or is a complex task. dangerous products by labeling dangers with an easily Traditionally such calculations were based upon the age or identifiable symbol. weight of a child as compared with those of a normal adult. Most medications for children are calculated based on the Drug therapy for older adult clients child’s weight until the child attains adult weight Older adults ( 65 years of age and over) make up about Calculation of body surface area (BSA) by the use of 13% of the US population and represent the fastest nomogram that combines height and weight data seems to growing segment of the population. provide fairly good correlation to appropriate pediatric dosage. They consume about 34% of all prescription drugs and purchase 30% of all over the counter (OTC ) medications. Guidelines for the administration of medications to children Approximately 80% of older adults have at least one 1. The nurse's approach to a child must be based on a chronic illness, and 50 % have at least two. (CDC, 2010) knowledge of growth and development and on the individual Most of these chronic conditions are medically treated needs and preferences of the child. with one or more medication per condition. 2. Establish a trusting relationship with the child. The Substance Abuse and Mental Health Services 3. Always be honest about what is unpleasant or painful, Administration ( SAMHSA, 2007) reports “ that older including mentioning the potentially unpleasant taste of an oral persons regularly consume on average between two and six medication. prescription medications and between one to three OTC 4. Use a kind but firm approach to the child. medications per day.” 5. Explain the procedure to the child in terms that are easily With the combined use of prescription and OTC understood. medications, many older adults take 10 drugs per day. Transcribed by: Shania Barbra Ruaya Polypharmacy 5. Use of nonprescription drugs, sharing medications, - the term used for multiple medications. hoarding drugs, and dietary factors are all related to drug - is used when too many medications are used by clients, when problems in the older adults. more drugs are prescribed than is clinically warranted or even 6. Communication difficulties also lead to drug problems. when all prescribed medications are clinically indicated. Nursing Care for the Older Adults Pharmacokinetic Differences in Older Adult Client 1. Take a history of allergies and current use of prescription and nonprescription drugs. Absorption 2. Identify potentially inappropriate medications Reduced gastric acidity because of the gradual reduction in 3. Obtain baseline vital signs, weight and height production of hydrochloric acid in the stomach that may affect 4. Obtain information on sensory functioning, home the way tablets or capsules dissolve. environment, social support network. Gastric emptying is slower because there is a decline motor 5. Review medications with each client every 6 to 12 tone and motor activity in GIT. months thereafter, and with any medication change. Older adults have a tendency for constipation 6. Closely monitor clients taking psychotropic medications and those taking more than four medications because they Distribution are greater risk for falls. Total body water (TBW) content is decreased, resulting in 7. Monitor renal function and collaborate with the health diminished volume of distribution of some water-soluble care provider regarding potential changes in dosages if medications. renal function declines. Total body fat content is increased Age related loss of muscle tone due to atrophy Nursing process in pharmacology There is a general decrease in protein-binding capability Assessment Metabolism Data collection The levels of enzymes are decreased because of the decline – Subjective, objective in liver function with age. – Data collected on the patient, drug, environment Liver blood flow is reduced thus, there is a decline in the Medication history body’s ability to transform active drugs into inactive Nursing assessment metabolites. Physical assessment There is an age-related decrease in liver volume Data analysis Older adults are more likely to experience hepatotoxicity Objective data: - Include information available through the senses Elimination - sources of data are the chart, laboratory test results, Glomerular filtration rate is reduced by 40-50% because of reports of diagnostic procedures, health history, physical the reduction of blood flow to the kidneys. assessment and examination findings The number of intact nephrons is decreased. Other examples include age, height, weight, allergies, Older adults are more likely to experience drug toxicity medication profile, health history because of accumulation of drugs. Subjective data: - all spoken information shared by the patient such as Factors Related to Drug Problems complaints, problems, or stated needs (patient complains of 1. Sensory losses affect the older adult’s ability to manage dizziness, headache, vomiting) medication programs accurately. 2. Loss of recent memory affects self-care. Safe Nursing Practice 3. Medication problems increase with the use of multiple Assessment : pharmacies and health care providers. 1. Take a medication history including current use of 4. As the number of drugs taken increases, medication errors prescription and OTC agents increase Transcribed by: Shania Barbra Ruaya 2. Assess the client’s understanding about illness, including 3. Focus on : past experience Why the drug is needed? 3. Conduct a physical assessment How the drug will be administered? 4. Obtain information about social networks and resources Common indications of adverse effects Other nursing measures that will enhance the likelihood Analysis of Data of achieving desired outcomes. - Once data about the patient and drug have been collected and reviewed, the Implementation nurse must critically analyze and synthesize the information. - Requires constant communication and collaboration with the patient and with members of the health care team Nursing diagnoses involved in the patient’s care, as well as the family - are prioritized in order of critically based on patient needs members. or problems. - The nurse needs to know and understand all of the Actual responses are always ranked above nursing diagnoses information about the patient. that involve only risks. “ Rights of giving medications” Judgment or conclusion about the need/problem (actual or at risk for) of the patient Safe nursing practice Based upon an accurate assessment Implementation : NANDA format Preparing Drugs for Administration Nursing diagnoses related to drug therapy may include the 1. Ensure cleanliness of hands, work area and supplies following: 2. Ensure availability of supplies - Ineffective health maintenance 3. Ensure adequate lighting - Noncompliance related to drug regimens 4. Decrease environmental distractions - Deficient knowledge (illness and its treatment) - Ineffective management of the therapeutic regimen Evaluation - Risk for injury - Occurs after the nursing care plan has been implemented - It is systematic, ongoing and a dynamic phase of the Planning nursing process as related to drug therapy - This includes identification of goals and outcome criteria - It includes monitoring of goals and outcome criteria, as The major purpose of the planning phase are to prioritize well as monitoring the patient’s therapeutic response to the the nursing diagnoses and specify goals and outcome criteria, drug and its adverse effects and toxic effects. including time frame for their achievement. Patient- oriented outcome criteria must apply to any Client teaching medications the patient will receive. 1. Client Teaching is an important nursing function that Identification of goals and outcome criteria enables the client to engage in self-care. Prioritization 2. To be effective, teaching must take into account the Time frame client’s readiness to learn, unique characteristics and life Goals situation. Objective, measurable, realistic 3. Teaching makes use of the nursing process Time frame specified 4. Clients should possess general knowledge of their illness Outcome criteria and its treatment. Specific standard(s) of measure Patient oriented Fostering compliance and cooperation with medication regimens Safe Nursing Practice Ideally, cooperation with treatment means that all Diagnosis and Planning: medication doses are taken correctly for the prescribed 1. State relevant nursing diagnoses length of therapy. 2. Identify desired outcomes of nursing intervention Transcribed by: Shania Barbra Ruaya  Some reasons for lack of cooperation include inadequate understanding of the illness, cost of medication, the development of adverse effects, and forgetfulness. A number of measures can be taken to foster the likelihood of cooperation. These include : - educational programs - memory aids - alterations in the number and doses of medication The nursing process is an important means of promoting cooperation. Transcribed by: Shania Barbra Ruaya