Assignment- 1 for MPT-104 1. 2. 3. Define drugs: Substances interact with specific target Molecules in the body, producing a Biological effect. The main uses of drugs are: treatment, prevention, & diagnosis of diseases Drug dosage form is Dosage form is the final form of a drug to make it easily Taken by patients Pharmacodynamics means What the drug does to the body. It deals with the biochemical and physiological effects of drugs and their mechanism of action 1. Pharmacokinetics : describes "what the body does to the drug". It explains the movement processes of the drug following its administration. It deals with absorption, distribution, metabolism and excretion 2. Define the dose of drug: The amount of the drug that achieves the desired effect without causing harmful side effect. 3. Mention the differences between Active and Passive diffusion of drugs: Active Passive The drug molecule moves against concentration gradient from low drug concentration to high drug concentration. • It needs a carrier and energy expenditure. • Shows saturability and selectivity. • Competition between drugs is present on the same carrier. 4. Write 4 factor affecting drug absorption? a. Blood flow b. Surface area c. Gastrointestinal motility 5. 6. 7. 8. Food 9. For Lipid-soluble drug • Along concentration gradient (from high to low conc.). • No need for energy or carrier. • Occurs with most drugs. Define drug bioavailability: fraction of administrated drug reaching systemic circulation unchanged How plasma protein binding affects drug distribution and excretion. Explain? The protein bound drugs are pharmacologically inactive. • The unbound fraction of the drug is active and exposed to the metabolism and/or excretion Male patient with heart failure and receives digoxin, accidentally he took an overdose of digoxin with appearance of toxicity manifestations. Doctor decide to send patient for hemodialysis to treat toxicity. What is your opinion and explain why agree or disagree with? False because hemodialysis is filtrationthe drug from the blood and digoxin is highly volume of destrubution 10. Give examples of phase I and phase II reactions of drug metabolism: Phase 1; oxidation and reduction Phase 2: conjugation and acytilation 11. Explain how genetic polymorphism affects drug metabolism? Genetic variation of the metabolic enzymes affect amount of enzymes 12. Give four examples of liver microsomal enzymes (CYP 450) inducers and two inhibitors. Enzyme enducer : alcohol – rifampin – phenytoin - carbuazepine Enhibitors:keto console – valproic acid – cimetidine 13. Alkalinization or acidification of urine will modify drug renal excretion explain and give examples? 14. NAHCO3 causes alkalization of urine – atropine 15. NH4CL and ascorbic acid cause acidification of urine as aspirine 16. What is the significance of enterohepatic circulation of drugs? Responsible for prolongation of duration of action of drugs 17. Causes of low oral bioavailability: Poor absorbtion 18. Define volume of distribution is a pharmacokinetic parameter that describes the apparent distribution of a drug throughout the body after administration 19. What is the Clinical significance of Vd: the volume of distribution is an important pharmacokinetic parameter that can provide valuable information for optimizing drug dosing regimens and monitoring drug therapy in clinical practice. 20. Mention the differences: First order kinetics Zero-order kinetics (Constant clearance) (Variable clearance) the rate of elimination of a drug is proportional to the drug concentration the clearance of a drug is constant and represents the amount of drug that is eliminated per unit of time the rate of elimination is constant and does not depend on the drug concentration. the clearance of a drug is variable and may depend on factors such as enzyme saturation, coadministration of other drugs, or disease states. 21. What are the uses of half-life (t1/2): 22. Determining dosing intervals and Predicting drug accumulation 23. Define spare receptors and give an example: Spare receptors, also known as reserve receptors or constitutive activity, are receptors that are not required to be occupied by an agonist to produce a maximal response - beta-adrenergic receptors in the heart 24. Give examples for the following: A. Intracellular receptors Steroid hormone receptors - thyroid hormone receptors 25. Ligand-gated ion channels: GABA receptor - Nicotinic acetylcholine receptor 26. Define desensitization, explain mechanisms, and give an example? Desensitization is a physiological process by which a cell or tissue becomes less responsive to a particular stimulus over time. This process is crucial for maintaining homeostasis in response to repeated or prolonged stimulation. beta-adrenergic receptors in the heart become desensitized to the effects of epinephrine and norepinephrine over time 27. What is partial agonist: give examples: A partial agonist is a type of ligand that binds to a receptor and produces a response, but the response is less than that produced by a full agonist. Partial agonists have a lower efficacy than full agonists, meaning that they are less able to activate the receptor fully- Buprenorphine 28. What are the differences between competitive and noncompetitive antagonists? Competitive antagonists compete with the agonist for binding to the same site on the receptor Noncompetitive antagonists, on the other hand, bind to a different site on the receptor than the agonist and prevent the activation of the receptor by altering the conformation of the receptor, blocking the ion channel, or inhibiting the downstream signaling 29. Give an example for: a. Chemical antagonism the use of protamine sulfate to counteract the anticoagulant effects of heparin b. Physical antagonism the use of naloxone to reverse the effects of opioid drugs such as morphine c. Physiological antagonism: the use of epinephrine and histamine in the treatment of anaphylaxis 28. Mention 4 characters of drug toxic reactions: a. Dose-Dependence b. Individual Sensitivity c. Time Course 29. Idiosyncrasy 30. What is the cause of idiosyncrasy. Give 3 different examples: genetic or immune system factors that lead to a unique and unpredictable response to a drug 1-Stevens-Johnson Syndrome (SJS) 2- Hemolytic Anemia 3- Drug-Induced Liver Injury 31. Define drug tolerance and tachyphylaxis: 32. Drug tolerance refers to a decreased response to a drug that occurs after repeated use. This means that over time, a higher dose of the drug is needed to produce the same effect that was initially achieved with a lower dose 33. Explain and underlying mechanism of pharmacokinetic tolerance to drug. Please give an example. Pharmacokinetic tolerance refers to a type of drug tolerance that occurs as a result of changes in the way a drug is absorbed, distributed, metabolized, or eliminated by the body. One underlying mechanism of pharmacokinetic tolerance is an increase in the activity of drug-metabolizing enzymes, such as the cytochrome P450 enzymes in the liver. These enzymes play a crucial role in the metabolism of many drugs, and an increase in their activity can lead to more rapid metabolism and elimination of the drug from the body. 34. What is cross tolerance, explain with examples: cross-tolerance refers to the phenomenon where the tolerance to a drug can lead to a reduced response to another drug that acts on the same receptors or pathways. example of cross-tolerance is between different types of stimulants, such as caffeine and amphetamines. If someone regularly consumes large amounts of caffeine, they may develop a tolerance to its effects. This tolerance may also extend to other stimulants, such as amphetamines or cocaine, leading to the need for higher doses of these drugs to achieve the desired effects.
