1. What are the main pharmacokinetic differences between children and adults, and how do they affect drug dosing and administration? (5 marks) Answer: Children have different pharmacokinetic profiles than adults due to their immature organ systems, higher metabolic rate, lower body fat, and higher body water. These factors affect drug absorption, distribution, metabolism, and excretion. For example, children may need higher doses of water-soluble drugs per kilogram of body weight than adults, but lower doses of lipid-soluble drugs. Children may also have faster or slower clearance of drugs depending on their age and developmental stage. Therefore, drug dosing and administration in children should be based on evidencebased guidelines, weight-based calculations, and frequent monitoring of drug levels and effects. 2. What are the main pharmacodynamic differences between pregnant and non-pregnant women, and how do they affect drug efficacy and safety? (5 marks) Answer: Pregnant women have different pharmacodynamic responses to drugs than non-pregnant women due to the physiological changes that occur during pregnancy, such as increased blood volume, cardiac output, renal blood flow, and plasma protein binding. These changes may alter the receptor sensitivity, affinity, number, and distribution of drugs in the body. For example, pregnant women may have increased or decreased effects of drugs such as betablockers, opioids, anticoagulants, and anticonvulsants. Therefore, drug efficacy and safety in pregnant women should be evaluated carefully, considering the potential benefits and risks for both the mother and the fetus. 3. What are the main pharmacogenetic factors that influence drug response in individuals and populations, and how can they be used to optimize drug therapy? (5 marks) Answer: Pharmacogenetics is the study of how genetic variations affect drug response in individuals and populations. These variations may affect drug metabolism, transport, target, or interaction with other drugs or environmental factors. For example, some individuals may have genetic polymorphisms that make them slow or fast metabolizers of certain drugs, such as warfarin, clopidogrel, codeine, or tamoxifen. These variations may result in altered drug efficacy or toxicity. Therefore, pharmacogenetic testing can be used to identify these variations and tailor drug therapy accordingly. 4. What are the main types of adverse drug reactions (ADRs), and how can they be prevented and managed? (5 marks) Answer: Adverse drug reactions (ADRs) are any undesirable effects of drugs that occur during normal use. They can be classified into two main types: type A (augmented) and type B (bizarre). Type A ADRs are dose-dependent, predictable, and related to the pharmacological action of the drug. They can be prevented by adjusting the dose, frequency, route, or duration of administration. Type B ADRs are dose-independent, unpredictable, and related to the immunological or idiosyncratic reaction of the individual. They can be prevented by avoiding known triggers or contraindications, screening for risk factors or allergies, and monitoring for signs and symptoms. Both types of ADRs should be reported to the appropriate authorities and managed according to the severity and causality of the reaction.