BNS 200 Introduction to Pharmacology 2025 PDF

Nursing Pharmacology 2025 Matshediso Matome At the end of this presentation the student should be able to:  Describe the interaction between core knowledge of drugs and core patient variables in maximizing therapeutic effects and minimising adverse effects  Define some pharmacolog...

Nursing Pharmacology 2025 Matshediso Matome At the end of this presentation the student should be able to:  Describe the interaction between core knowledge of drugs and core patient variables in maximizing therapeutic effects and minimising adverse effects  Define some pharmacology terms  Identify the major drug classifications and their primary mechanisms of action  List the various routes of administration of drugs.  List source of drugs  Describe the drug development process  Describe legal aspects relating to sale and supply of medicines in Botswana  Identify safety protocols in administering medications, including the "Six Rights  Recognize the importance of adhering to ethical and legal responsibilities in medication administration.  Summarize the role of pharmacology in patient care, particularly in nursing practice.  Group exercise at the end. Contributes 2 marks to final score  Focus on drug therapy management by nurses with a focus on potential interaction between CORE DRUG KNOWLEDGE/VARIABLES and CORE PATIENT VARIABLES so as to, 1. Maximise therapeutic effects 2. Minimise adverse effects 3. Provide patient and family education 4. Evaluate effectiveness of the drug therapy  Core drug knowledge/variables will cover the following key areas/variables relating to pharmacological agents. ◦ Pharmacotherapeutics – Why prescribed ◦ Pharmacokinetics – What body does to drug ◦ Pharmacodynamics – What drug does to body ◦ Contraindications and Precautions – indicate restrictions in use or need for close monitoring  What is the difference between contraindication and precaution? ◦ Adverse effects - ◦ Drug Interactions – ◦ Appropriate administration-  Choose the correct Drug/medicine variable core drug variable in  Pharmacotherapeutic relation to Aspirin for use each of the description  Contraindication provided below  Precaution ◦ Asthma  Adverse effect ◦ Corticosteroids  Drug interactions ◦ Elderly ◦ Analgesia ◦ Peptic ulceration ◦ Tinnitus  Consider interaction between core drug knowledge and the following core patient variables, 1. Health status – assessment of acute and chronic ailments, organ dysfunction allergies, drug history etc 2. Lifespan – e.g. age, physiological development 3. Gender 4. Lifestyle –e.g. use of OTC, use of alternative health practices, ability to afford drug therapy etc 5. Environment e,g. setting where drug admin will take place 6. Culture 7. Inherited traits  Explain why it is important for a nurse to conduct the following assessment in relation to patient drug therapy ◦ Health and drug history ◦ Lifespan assessment ◦ Examination of the following medical records,  Current laboratory findings?  Other diagnostic findings?  The chemical name: is the name by which the chemist knows it: N-acetyl-para-aminophenol (APAP)  The generic name: is given for the drug it is the official name: Paracetamol/acetamenophen  The trade mark or brand name (proprietary name) : is name given by the drug manufacturer: Panado  Similarities between brand and generic  Differences between brand and generic  Public perception  Public protection  Therapeutic classification: ◦ Based on their therapeutic usefulness in treating diseases  Pharmacological classification: ◦ The way the agent works i.e its mechanism of action  Mechanism of Pharmacological Therapeutic Therapeutic action classification usefulness classification Lowers plasma Influences volume diuretic blood clotting Anticoagulant Blocks calcium calcium channel cahnnels blocker Lowers blood cholesterol Antilipedimiacs Blocks angiotensin Lowers blood (hormaonal pressure Antihypertensives activity) ACE inhibitor Therapeutic classification Pharmacological classification cardiac agenta of antihypertensives Abbreviation Meaning STAT Immediately, only once – timeframe 5min ASAP Urgent, timeframe 30min prn As required by patient condition Abbreviation Meaning gtt drop pc After meals Hs, nocte bedtine ac Before meals qd daily qod qid bd tid tds  Pharmacology: is a science that studies the effect of the drugs on the body ◦ In the broadest sense, pharmacology is the study of how chemical agents, both natural and synthetic (i.e., drugs) affect biological systems. But covers other disciplines  Pharmacopeias: an official publication containing a list of medicinal drugs with their effects and directions for their use.  Formulary: a list of drugs that are approved to be prescribed by a particular health specific health system or hospital. Drug formularies are developed based on the efficacy, safety and cost of the drugs.  The therapeutic effect: Is the primary effect intended that is the reason the drug is prescribed ◦ What is the therapeutic effect of morphine? ◦ What is the therapeutic effect of ibuprofen?  Therapeutic Indication: The therapeutic indication is the primary use for which the medicine is approved. It should clearly state the disease/condition and population that a medicine is intended to treat. E.g. chlorpheniramine, amitryptalline  Off label use of medicine – what does it mean.  Some examples of off label use of common medicines e.g Low dose amitriptyline to improve sleep maintenance in patients with insomnia disorder.  Side effect: secondary effect of the drug is one that is unintended, side effects are usually predictable and may be either harmless or harmful. ◦ What is a common GIT side effect of morphine?  Adverse effect: Harmful, unintended reactions to medicines that occur at doses normally used for treatment, including lack of efficacy, and which occurs at doses normally used in man and which can also result from overdose, misuse or abuse of a medicine  dose-related (Augmented), non-dose-related (Bizarre), dose- related and time-related (Chronic), time-related (Delayed), withdrawal (End of use), and failure of therapy (Failure). ◦ What is a common adverse effect of aspirin?  Drug toxicity: deleterious effect of the drug on an organism or tissue, result from overdose  Drug allergy: is immunological reaction to a drug.  Therapeutic Threshold – The minimum amount of a medicine that is required to cause the desired response Tolerance: A decreasing response to repetitive drug doses. Increased doses are required to achieve the desired effect  Drug interaction: occur when administration of one drug before or after alter effect of one or both drug ◦ Example – Doxycycline and Iron  Drug misuse: Is the improper use of common medications in way that lead to acute and chronic toxicity for ◦ example laxative, cough mixtures  Drug abuse: is an inappropriate intake of substance either continually or periodically  Drug dependence: is a persons reliance on or need to take drug or substance there are two type of dependence ◦ Illicit drug: also called street drug are those sold illegally e.g. cannabis, heroine,cocaine etc..  Physiological dependence: is due to biochemical changes in the body tissue these tissue come to require substance for normal function.  Psychological dependence: is emotional reliance on a drug to maintain a since of wellbeing accompanied feeling of need.  Potentiation ◦ The enhancement of a medicine’s effect by another medicine ◦ E.g. promethazine may enhance the sedative effect of morphine; also alcohol  Synergism ◦ The combined action of 2 or more medicines that is greater than the sum of the 2 medicines acting independently e.g. co-trimoxazole  Pharmacokinetics: is a Pharmacodynamics: Is a study of what the body study of what the drug does to the drug. does to the body. Detailed discussion later Detailed discussion later Pharmacognosy: The Pharmacotherapeutics: is study of natural (plant a clinical using of drug and animal) drug in patients sources  Routes of administration Systemic Local Enteral Parenteral Topical ❑ Enteron meaning intestine therefore refers to drugs directly placed in the GIT and include ❑ Oral ❑ Buccal ❑ Sublingual ❑ Rectal Oral continued Advantages:  Easy to administer  Convenient  Cost effective Disadvantage:  Inappropriate for client with nausea and vomiting  Drug may have unpleasant taste  May cause irritation of gastro intestinal tract  Drug can be aspirated by ill client  Some drugs not available in oral formulation 2. Sublingual: a drug placed under the tongue, where it dissolved. Advantage:  Same as oral plus  Drug may administered for local effect or systemic effects.  Drug rapidly absorbed into blood stream.  More biovalable than oral.  Quicker onset of action Disadvantage/caution: Sublingual  If swallowed drug may be inactive  Drug must remain under the tongue until dissolved What advise would you give to a patient in the ward who has been prescribed a sublingual formulation?  Pertaining to the cheeks 4. Rectal: can be used when drug objectionable taste When else do you think rectal administration of drugs may be indicated? What type of formulations are usually administered rectally? When is rectal administration contraindicated? ◦ Lack of consent ◦ Recent rectal or anal surgery ◦ Abnormalities or trauma involving the perineal or perianal areas; ◦ Suspected colonic obstruction  Refers to drugs given by routes other than the digestive tract or topical. Usually used for drugs given by injection or infusion by-passing the skin.  Delivers drugs into the skin by needle e.g IM,IV,Subcat  What are the common parenteral routes that you know of???  Usually used for drugs that ◦ Can be used for drugs that are poorly absorbed, inactive or ineffective if given orally ◦ The IV route provides immediate onset of action ◦ The intramuscular and subcutaneous routes can be used to achieve slow or delayed onset of action  Needle Degree of Gauge and Total Amount of Injectable Angle When Injection Types Length Fluid Injecting Considerations 25-27G Older adults have decreased skin elasticity, so the skin should be held taut to ensure the medication is Intradermal 3/8” to 5/8” 0.1 - 0.2 mL 5-15 degree administered properly. The older patient’s skin is less elastic, and subcutaneous 23-25 or 35- tissue may be reduced in the 27 Up to 1 mL skinfolds. The upper abdomen can be Up to 0.5 mL in infants and used for patients with less Subcutaneous 1/2” to 5/8” small children 45-90 degree subcutaneous tissue. 0.5-1 mL (infants and 18 to 25G children) 1/2” to 1 1/2” (based on age/size of patient and site Intramuscular used) 2-4 mL (adults) 90 degree 19-21G Intravenous 1-1.5 inch 5. Subcutaneous (SC): hypodermic into subcutaneous tissue, just below the skin. Advantage: onset drug action faster than oral. Although parenteral patients can self administer, with training, therefore convenient Disadvantage: SC Must involve sterile technique because breaks skin barrier. More expensive than oral. Can administer only small doses. Onset is slower than intramuscular injection. Some drug can irritate tissue and can cause pain. 6.Intramuscular (IM): into in the muscle. Advantage:  Pain from irritating drugs is minimized  Can administer large volume of drug  Drug rapidly absorbed  Can be used for depot formulations – examples? Disadvantage:  breaks skin barrier  Can be anxiety producing  Requires training 7. Intradermal (ID): is the administrating of a drug into the dermal layer of the skin just beneath the epidermis, usually small amount of liquid is used for example 0.1ml.  Advantage: absorption is slow (this advantage test for allergy)  Disadvantage: amount of drug administered must be small  Breaks skin barrier 8. Intravenous (IV): allow injection of drugs and another substance directly into bloodstream through the vein Advantages Provides immediate onset of action Disatvantages Staff need additional training and assessment Can be costly Aseptic technique is required May require additional equipment Not all formulations amenable to this route Carries the greatest risk of any route of drug administration It may require dose calculations, dilutions, information to be gathered on administration rates and compatibilities with other IV solutions 8. Intravenous (IV): allow injection of drugs and another substance directly into bloodstream through the vein Types of IV administration Large volume infusion Intermittent infusion IV Bolus administration 1. Intrathecal: inject onto CSF. 2. Intrapleural: injected onto plural cavity. 3. Intraosseous: injected into rich vascular network of long bone. 4. Epidural: inject to epidural space. 5. Intraarticular: inject onto joint.  Aseptic techniques must be applied The nurse must identify and use appropriate material for parenteral drug delivery including specialized equipment and technique involved in the preparation and administration of injectable products. Know the correct anatomical site for administration Know safety procedure regarding harzadous equipment disposal Th ❑ Applied to the skin and mucus membranes. Typically produce local effect but exceptions exist. subcategories include. o Skin (including transdermal patches) o Eyes o Ears o Nose o Lungs (inhalation) o Vagina  Inhalation: is apply to drugs directly onto lungs Please give examples of conditions where inhalation therapy is indicated. Advantages of inhalation therapy  Solid dosage Liquid dosage forms forms Tablets Capsules Powders Solutions Suspensions Elixirs Tincture Sustained release Effervescent Enteric coated  Which of the following would be the preferred route/s of administration for a highly lipid soluble drug that undergoes extensive first pass metabolism?  A. Orally  B. Intravenously  C. Transdermal  D. Sublingually  Safety: ✓ An ideal medicine should be safe even at high concentrations and for long periods of administration in real practice there is no such thing as a safe medicine ✓ An ideal medicine should be safe and not be habit forming but some medicines are habit forming e.g. opioid analgesics ✓ An ideal medicine should be safe and devoid of side effects and adverse effects but all medicines have side effects e.g. excessive dosage of opioid analgesics carries a risk of respiratory failure, cancer drugs increase infections, aspirin causes gastric ulcer etc.  Selectivity: One that elicits only the response for which it is given Selective for specific reaction with no side effects (there is no such thing) Drowsiness can be caused by antihistamines Constipation, urinary hesitance, and respiratory depression can be caused by morphine  Ease of Administration – an ideal medicine should have few doses and be easy to administer to patients increase adherence & decrease medication errors –Not the case e.g. diabetic patients need multiple daily injection of insulin administered by subcutaneous route 4. Freedom from drug interactions – Should not augment or decrease action of other drugs Respiratory depression caused by diazepam which is normally minimal, can greatly be intensified by alcohol. Antibacterial effects of Tetracycline can be greatly reduced by taking iron or calcium supplements 5. Low Cost-an ideal drug should be affordable but this is not always the case : – Easy to afford (especially with chronic illness)but this is not he case with the following medications : Growth hormone costs between $10,000 and $20,000 Cancer medication and cost Lifelong medication for hypertension, arthritis, diabetes etc. are expensive THEREFORE: – No medicine is entirely safe – All medicines have side effects – Responses to medicines may be difficult to predict – Medicines may be expensive – Medicines may be hard to administer All members of health care team must exercise care to promote therapeutic effects and minimize drug induced harm  The aim is to give a patient a dose of the drug that achieves the desired effect without causing harmful side effect.  Therapeutic index: is a measure of the danger of poisoning and the higher it is the safer the drug is. ◦ Morphine (70), Diazepam (100), Asp. ◦ Which one of the above is likely to be safer, based on TI?  Therapeutic range?- Define therapeutic range and compare that to therapeutic index  Bioavailability: Is the extent to which the drug reaches the systemic circulation following administration. Expressed as fraction of dose that reaches the systemic circulation UNCHANGED. ◦ What do you think would be the bioavailability of IV formulation of Drug X versus its oral formulation? ◦ Why is it important to know whether a drug has adequate bioavailability?  To provide maximum benefit with minimum harm Main factors that determine intensity of medicines response Administration – dosage size and route of administration Pharmacokinetic processes Pharmacodynamics Individual Variations NEXT STEPS  Discuss the nurses’ legal responsibilities in administering medications, including proper documentation. ◦ HFD register for the ward: must be used to record details of any Schedule 1 Controlled Drugs received or supplied in the ward.  Ethical dilemma – Patient’s refusal of medication ◦ Situation:A nurse accidentally administers a double dose of a prescribed medication due to a miscommunication in the medication order. The patient begins to experience mild side effects, such as dizziness and nausea. ◦ What is the ethical dilemma in this case? Non- maleficence vs. Accountability ◦ What do you think is a reasonable nursing response in this case?  In one paragraph please discuss how you think pharmacology applies to your current or future nursing roles. ◦ Please make sure that when you hand over assignment, it contains the names of all your group members. Only those that are here now.