REVISION UNITS 34 68 Q1 Discuss in detail the processes of

REVISION: UNITS 3-4 & 6-8 Q1. Discuss in detail the processes of pharmacokinetics: Pharmacokinetics refers to what the body does to a drug. The four process are absorption, distribution, metabolism (or biotransformation), and excretion (or elimination).Absorption is the movement of drug particles from the GI tract to body fluids by passive absorption, active absorption, or pinocytosis. Most oral drugs are absorbed into the surface area of the small intestine through the action of the extensive mucosal villi. The drug moves from the intestine into the blood stream. The blood containing the drug flows through the liver.Distribution is the process by which the drug becomes available to body fluids and body tissues. The drug leaves the blood stream and enters the tissues where it exerts its effects.Drugs can be metabolized in both the GI tract and liver; however, the liver is the primary site of metabolism. Most drugs are inactivated by liver enzymes and then converted or transformed by hepatic enzymes to inactivate metabolites or water soluble substances for excretion. The main routes of drug elimination is through the kidneys (urine). Other routes include hepatic metabolism, bile, faeces, lungs, saliva, sweat, and breast milk. Q2. Which 2 organs are usually involved in metabolism?Liver and GI tract Q3. Name 3 ways drugs are excreted from the body.Urine, faeces, sweat Q4. What are the three main ways that drugs generally act in the body? Q4. Explain nurse’s role in preventing serious adverse drug effects in patients. Q5. Write the mechanism of action of each of the following drugs and state one indication for each. a) Aspirin A nonsteroidal salicylate that inhibits prostaglandin synthesis, acts on the hypothalamus heat- regulating centre, and interferes with the production of thromboxane A,a substance that stimulate platelet aggregation.Therapeutic effect: reduces inflammatory response and intensity of pain; decreases fever; inhibits platelet aggression.Analgesia, feverb) Prednisolone an adrenocortical steroid that inhibits inflammation sites, phagocytosis, lysosomal enzyme release and synthesis, and release of mediators of inflammation.Therapeutic effect: prevents or suppresses cell-mediated immune reactions. Decreases or prevents tissue response to inflammatory process.Substitution therapy for deficiency states: acute or chronic adrenal insufficiencyc) AcyclovirA synthetic nucleoside that converts to acyclovir triphosphate, becoming part of the DNA chain.Therapeutic effect: interferes with DNA synthesis and viral replication. Genital herpes d) Albendazole A Benz imidazole carbamate anthelmintic that degrades parasite cytoplasmic microtubules, irreversibly blocks cholinesterase secretion and glucose uptake in helminth and larvae (depletes glycogen, decrease ATP production, depletes energy). Vermicidal.Therapeutic effect: immobilizes and kill worms.Neurocysticercosise) Heparin A blood modifier that interferes with blood coagulation by blocking the conversion of prothrombin to thrombin and fibrinogen to fibrin. Therapeutic effect: prevents further extension of existing thrombi or new clot formation. Has no effect on existing clots.Treatment of venous thrombosis, pulmonary embolism, peripheral arterial embolism, atrial fibrillation with embolism.f) Metformin An antiperglycemic that decreases hepatic production of glucose. Decreases absorption of glucose and improves insulin sensitivity.Therapeutic effect: improves glycemic control, stabilizes or decrease body weight, and improves lipid profile.Diabetes mellitus type 2g) Nifedipine An antianginal and antihypertensive agen that inhibits calcium ion movement across cell membranes, depressing contraction of cardiac and vascular smooth muscle.Therapeutic effect: increases heart rate and cardiac output. Decreases systemic vascular resistance and BP.Essential hypertensionh) Digoxin A cardiac glycoside that increases the influx of calcium from extracellular to intracellular cytoplasm.Therapeutic effect: potentiates the activity of the contractile cardiac muscle fibers and increase the force of myocardial contraction. Slows the heart rate by decreasing conduction through the SA and AV nodes.control of ventricular rate in patients with artrial fibrillationi) Frusemide A loop diuretic that enhances the excretion of sodium, chloride, and potassium by direct action at the ascending limb of the loop of henle.Therapeutic effect: produces diuresis and lowers BP.Edema, hypertensionj) Ketoconazole A fungistatic antifungal that inhibits the synthesis of ergo sterol, a vital component of fungal cell formation.Therapeutic effect: damages the fungal cell membrane, altering its function.Systemic fungal infection such as histoplasmosis, blastomycosis