Pharmacology Intro PDF

1 PHARMACOLOGY HAYRES BOOTS S. SABIO RN, MAN, EdD HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 2 PHARMACOLOGY a branch of medicine and pharmaceutical sciences which is concerned with the st...

1 PHARMACOLOGY HAYRES BOOTS S. SABIO RN, MAN, EdD HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 2 PHARMACOLOGY a branch of medicine and pharmaceutical sciences which is concerned with the study of drug or medication action. is the field of science that focuses on the study of drugs and their reactions in the human body. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 3 PHARMACOTHERAPEUTICS/CLINICAL PHARMACOLOGY the branch of pharmacology that uses drugs to treat, prevent, and diagnose disease. 2 KEY CONCERNS: A. Drug effects on the body B. the body’s response to the drug HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 4 SOURCES OF DRUG INFORMATION DRUG LABELS one of the most important aspects of dispensing a prescription. The label must comply with state and federal regulations and should correctly and clearly convey all necessary information regarding dosage, mode of administration, and proper storage of the product. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 5 LET’S PRACTICE!!! Go to your medicine cabinets and drug labels from the boxes of drugs in your home. Next, open and paste the box on another sheet of paper and identify the following: Brand name, Generic name, Dosage, expiration date, and special drug warnings. Some labels also indicate the route and dosage for administration. Take picture and forward to me after. Thank you! HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 6 PACKAGE INSERT a document included in the package of a medication that includes details and directions that health care providers need to prescribe a drug properly, including approved uses for the drug, contraindications, potential adverse reactions, available formulations and dosage, and how to administer the drug. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 7 LET’S PRACTICE!!! Go to your medicine cabinets and look for package inserts in any available boxes of drugs in your home. Next, paste the package insert on another sheet of paper and identify the following: Brand name, Generic name, Dosage, Indications, Mechanism of action, Indication, Contraindications, Side effects etc. Take picture and forward to me after. Thank you! HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 8 REFERENCE BOOKS JOURNALS INTERNET INFORMATION HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 9 NICE TO KNOW: Why do drugs have 2 names? Every drug has an approved generic or medical name, decided on by an expert committee. Many drugs are also known by a brand or trade name chosen by the pharmaceutical company making and selling that drug as a medicine. So, for example, the drug paracetamol (generic name) is also known as Panadol (brand name). HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 10 All drugs have several names, which may cause confusion. When administering the prescribed drug, the spelling on the drug package must correspond exactly with the spelling of the drug ordered to ensure that the proper medicine is administered. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 11 Each drug has names: (1) a chemical name; (2) a generic name; and (3) a brand name. The chemical name is most meaningful to the chemist. By means of the chemical name, the chemist understands the exact chemical constitution of the drug as well as the exact placement of its atoms or molecular groupings. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 12 Before a drug becomes official, it is given a generic name or common name. The generic name is simpler than the chemical name. It may be used in any country and by any manufacturer. The first letter of the generic name is not capitalized. Students are strongly encouraged to learn and refer to drugs by their generic names, because formularies (i.e., lists of medicines available through a pharmacy) are maintained by generic names. When a therapeutically equivalent drug becomes available in generic form, the generic medicine is routinely substituted for the brand-name medicine. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 13 Generic names are provided by the U.S. Adopted Names Council, which is an organization sponsored by the U.S. Pharmacopeial Convention, the American Medical Association, and the American Pharmacists Association. The official name, which is virtually always the generic name in the United States, is the name under which the drug is listed by the U.S. Food and Drug Administration (FDA). The FDA is empowered by federal law to name the drugs for human use in the United States. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 14 A trademark or brand name is followed by the symbol ®. This symbol indicates that the name is registered and that the use of the name is restricted to the owner of the drug, which is usually the manufacturer. Most drug companies place their products on the market under brand names rather than generic names. The brand names are deliberately made easier to pronounce, spell, and remember. The first letter of the brand name is capitalized. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 15 ‘’ORPHAN DRUGS" are medicinal products intended for diagnosis, prevention or treatment of life-threatening or very serious diseases or disorders that are rare. These drugs are called “orphan” because under normal market conditions the pharmaceutical industry has little interest in developing and marketing products intended for only a small number of patients. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023  CLASSIFICATION OF DRUGS 16 A drug of any type can be classified into four broad categories. Let us study these categories in some detail. BASED ON PHARMACOLOGICAL EFFECTS A drug creates a pharmacological effect, i.e. the effects of a drug on the human body. This effect will cure what is ailing the body and have a positive biological response. So they are classified on the basis of what kind of effect they have in the body. For example, Analgesics relieve the body from pain An antibiotic drug will cure infections Antiseptics will kill germs and microorganisms HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 17 So any drug in the same category can have many compositions, dosages and brand names. But the net effect will be the same HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 18 BASED ON DRUG ACTIONS This classification is based on which biochemical process the drug targets in the body A biochemical process is the complex chemical reactions that occur inside the human body to keep it functioning normally. Like the production of enzymes is a biochemical process. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 19 Example antihistamines are taken to stop the production of histamines so that swellings and allergies can be controlled. So no matter which antihistamine drug you take, their ultimate aim will be to target and reduce the production of the histamines in your body. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 20 BASED ON MOLECULAR STRUCTURE This classification is based on the macromolecule the drugs interact with. The drug targets can be carbohydrates, lipids, proteins, nucleic acids or any other such biomolecule. The drugs with similar structures have similar reactions with such biomolecules. This is the preferred method of classification of chemists. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 21 BASED ON CHEMICAL STRUCTURE It is seen that drugs that have a similar molecular structure, have the same pharmacological effects and similar drug actions. The slight variation in their structures gives them different potential. But the basic skeleton of their structure remains the same. So this becomes one more way for us to classify a drug. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 22 SAMPLE QUESTION: Question: Which of the following is a medicine? A. Arsphenamine B. Heroin C. Cocaine D. None of the above HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 23 Answer: The correct option is A. Only drugs that have the desired effect of curing or preventing diseases are medicines. And in this case, Arsphenamine is a medicine used to treat infections. The other two options are narcotics, that are harmful to our health and are illegal. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 24 NICE TO KNOW: Drugs (from the Dutch droog, meaning “dry”) are chemical substances that have an effect on living organisms. Therapeutic drugs, which are often called medicines, are those drugs that are used for the prevention or treatment of diseases. Up until the early to mid twentieth century, dried plants were the most abundant source of medicines; thus, the word drug was applied to them. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 25 Drug therapy: treatment with drugs Diet therapy: treatment with diet (e.g., a low-salt diet for patients with cardiovascular disease) Physiotherapy: treatment with natural physical forces (e.g., water, light, heat) Psychological therapy: the identification of stressors and methods that can be used to reduce or eliminate stress Most illnesses caused by diseases require a combination of therapeutic methods for successful treatment. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 26 the two main areas of pharmacology are pharmacodynamics and pharmacoki netics. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 27 PHARMACODYNAMICS Pharmacodynamics studies the effects of a drug on biological systems. discusses the chemicals with biological receptors action of drugs on the human body HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 28 What are examples of receptors? Key Points Chemoreceptors detect the presence of chemicals. Thermoreceptors detect changes in temperature. Mechanoreceptors detect mechanical forces. Photoreceptors detect light during vision. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 29 CELLULAR RECEPTORS are proteins either inside a cell or on its surface, which receive a signal. In normal physiology, this is a chemical signal where a protein-ligand binds a protein receptor. The ligand is a chemical messenger released by one cell to signal either itself or a different cell. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 30 DRUG ACTION HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 31 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 32 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 33 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 34 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 35 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 36 THERAPEUTIC INDEX The therapeutic index (TI; also referred to as therapeutic ratio) is a quantitative measurement of the relative safety of a drug. It is a comparison of the amount of a therapeutic agent that causes the therapeutic effect to the amount that causes toxicity HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 37 TI = Therapeutic Index TI = _________toxic dose _ TD50 dose for therapeutic response ED 50 e.g TD 50 is 200 ED 50 is 20 TI = 10 A clinician would consider a drug safe if it had TI of 10 than if it had a TI of 3. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 38 The related terms therapeutic window or safety window refer to a range of doses which optimize between efficacy and toxicity, achieving the greatest therapeutic benefit without resulting in unacceptable side-effects or toxicity. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 39 DRUG SAFETY Drug safety is the main aspect of medical therapy that can play a major role in deciding which drug should be given to a patient. Also, considering the concept of benefit–risk balance, we found that drugs with a high risk profile should be avoided unless needed HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 40 NICE TO KNOW: The difference between the usual effective dose and the dose that causes severe or life-threatening side effects is called the margin of safety. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 41 MARGIN OF SAFETY (MOS) It is the ratio of toxic dose to 1% of the population (TD 01) to the dose that is 99% effective to the population. MOS = TD 01 ED 99 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 42 POTENCY vs EFFICACY Potency is an expression of the activity of a drug in terms of the concentration or amount of the drug required to produce a defined effect, whereas clinical efficacy judges the therapeutic effectiveness of the drug in humans. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 43 PHARMACOKINETICS is the study of the bodily liberation, absorption, distribution, metabolism, and excretion of drugs. what the body does with the drug HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 44 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 45 PHARMACOKINETICS pharmacokinetics studies the effects of biological systems on a drug. discusses the liberation, absorption, distribution, metabolism, and excretion (LADME) of chemicals from the biological systems. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 46 Pharmacokinetics (from Ancient Greek pharmakon "drug" and kinetikos "moving, putting in motion"; sometimes abbreviated as PK, is a branch of pharmacology dedicated to determine the fate of substances administered to a living organism. The substances of interest include any chemical xenobiotic such as: pharmaceutical drugs, pesticides, food additives, cosmetics, etc. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 47 When describing the pharmacokinetic properties of the chemical that is the active ingredient or active pharmaceutical ingredient (API), pharmacologists are often interested in L-ADME: Liberation – How is the API disintegrated (for solid oral forms (breaking down into smaller particles), dispersed, or dissolved from the medication? Absorption – How is the API absorbed (through the skin, the intestine, the oral mucosa)? Distribution – How does the API spread through the organism? Metabolism – Is the API converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic? Excretion – How is the API excreted (through the bile, urine, breath, skin)? HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 48 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 49 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 50 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 51 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 52 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 53 METABOLISM HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 54 DRUG METABOLISM is the term used to describe the biotransformation of pharmaceutical substances in the body so that they can be eliminated more easily. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 55 EXCRETION HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 56 Drugs may be further classified as prescription or nonprescription. Prescription drugs require an order by a health professional who is licensed to prescribe drugs, such as a physician, a nurse practitioner, a physician assistant, a pharmacist, or a dentist. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 57 Nonprescription or over-the-counter (OTC) drugs are sold without a prescription in a pharmacy or in the health section of department or grocery stores. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 58 Illegal drugs, which are sometimes referred to as recreational drugs, are drugs or chemical substances used for nontherapeutic purposes. These substances are obtained illegally or have not received approval for use by the FDA. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 59 Drug products made by different manufacturers or in different batches by the same manufacturer must be uniformly pure and potent. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 60 PRECLINICAL TRIALS A study to test a drug, a procedure, or another medical treatment in animals. The aim of a preclinical study is to collect data in support of the safety of the new treatment. Preclinical studies are required before clinical trials in humans can be started. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 61 PHASE I STUDIES the first tests of a drug with a small number of healthy human subjects. Patients are generally only used if the mechanism of action of a drug indicates that it will not be tolerated in healthy people. The typical Phase I trial has a single ascending dose (SAD) design, meaning that subjects are dosed in small groups called cohorts. Each member of a cohort might receive a single dose of the study drug or a placebo. A very low dose is used for the first cohort. The dose is then escalated in the next cohort if safety and tolerability allow. Dose escalation is stopped when maximum tolerability and/or maximum exposure is reached. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 62 PHASE II STUDIES performed on larger groups of patients and are designed to assess the efficacy of the drug and to continue the Phase I safety assessments. treatment duration of 12 to 16 weeks 2 PHASES: 1. Phase IIA is designed to assess dosing requirements. 2. Phase IIB focuses on drug efficacy. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 63 PHASE II studies maybe removed from further investigation for the ff reasons: a. Less effective than anticipated b. too toxic when used with patients c. produces unacceptable adverse effects d. low benefit risks ratio e. not anymore effective than other drugs already in the market, making the cost continued research and production less attractive to drug company. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 64 PHASE III STUDIES investigate the efficacy and safety of a new drug over 6 to 12 months or longer in a large patient population (several hundred patients or more) under conditions that reflect daily clinical life much more closely than the Phase I or II trials and allow evaluation of the overall benefit-risk relationship of the drug. prescribers asks patient to keep a journals and record any symptoms they experience. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 65 FDA APPROVAL drugs that finishes phase III studies are evaluated by the FDA, which relies on committee of experts familiar with the specialty area in which the drugs will be used. Only those drugs that are approved by FDA can be marketed. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 66 PHASE IV STUDIES Known as post-marketing surveillance trials involving safety surveillance (pharmacovigilance) and ongoing technical support after approval. However, not all Phase IV studies are post-marketing surveillance studies. There are multiple observational designs and evaluation schemes that can be used in Phase IV studies to assess the effectiveness, cost-effectiveness, and safety of an intervention in real-world settings. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 67 The FDA PREAGNANCY CATEGORIES: Category A: Controlled studies in women have failed to demonstrate a risk to the fetus in the first trimester and there is no evidence of risk in later trimesters. Category B: Either animal‐reproduction studies have not demonstrated a fetal risk but there are no controlled studies in pregnant women, or animal studies have demonstrated risk to the fetus that was not confirmed in controlled studies in pregnant women in the first trimester and there is no evidence of a risk in later trimesters. Medications in this class are generally considered safe. Examples of medications in this class are acetaminophen and amoxicillin. TRIVIA Acetaminophen and paracetamol are the same Acetaminophen named in US and Japan while Paracetamol is from Europe and the rest of the world. HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 68 Category C: Studies in animals have revealed adverse effects on the fetus and there are no controlled studies in women, or studies in women and animals are not available. Drugs from this class can be given to pregnant women if the benefit to the mother outweighs the risk to the fetus. Examples of medications in this class are diltiazem (Ca channel blocker that treats high blood pressure and relieve chest pain) and spironolactone (a diuretic that treats high blood pressure and heart failure). Category D: Evidence of human fetal risk has been documented, but the benefits to the mother may be acceptable despite the risk to the fetus. Drugs in this class may be used in pregnancy if the benefits to the mother outweigh the risk to the fetus (i.e. a life threatening situation or a serious disease for which safer medication cannot be used or are not efficacious). Examples of medications in this class are phenytoin (mgt and tx of epilepsy) and valproic acid (tx of epilepsy, bipolar disorder and prevention of migraine). HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 69 Category X: Studies in animals or humans have demonstrated teratogenic effects. The risk to the fetus clearly outweighs any potential benefit to the mother. Drugs in this category are contraindicated in pregnancy. Examples of medications in this class are thalidomide (treat and prevent erythema nodosum leprosum skin dse associated with leprosy) and warfarin (prevent blood clots from forming or growing larger in your blood and blood vessels). HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 70 FACTORS INFLUENCING RESPONSE TO DRUGS weight Psychological factors (attitude age towards a drug) Gender Environmental factors Physiological factors (temperature, sunlight can affect (acid-base balance, drugs efficacy) hydration, electrolyte tolerance Cumulation (not following balance) instruction and taking shorter Pathological factors (GI time) disorders, low BP) Interactions (2 to 3 drugs taking Genetic factors together) Immunological factors (people that has allergy to HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 some drugs/food) 71 QUIZ 1: Give the 5 sources of drug information? State the 2 main areas of pharmacology? What are the 3 names in a drug? HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 72 REFERENCES www.evolve elsevier https://en.wikipedia.org/ https://www1.health.gov.au/ https://nursekey.com/ Focus on Nursing Pharmacology, 7th edition, Amy M. Karch HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023 73 HAYRES BOOTS S. SABIO RN, MAN, EdD 8/18/2023