Pharmacokinetics, Pharmacodynamics, Pharmacology of Autonomic nervous system drugs, Autocoids
1. The apparent volume of distribution of a drug.
a. T: basic drugs are more widely bound to tissue proteins.
b. F: Vd relates the amount of drug in the body to its TOTAL concentration in the plasma.
c. F
d. T: in cardiac failure, cardiac output decreases which in turn reduces drug distribution to the peripheral sites.
2. Binding of drugs to plasma proteins show the following characteristics:
a. F: only the free unbound drug fraction is pharmacologically active as it can pass through the capillary membrane to various tissues.
b. F: the tendency to cause adverse effects is dependent on the therapeutic index of the drug and the amount displaced.
c. F: some acidic drugs like aspirin are strongly bound to plasma proteins but not to tissues.
d. T: may be due to accumulation of some organic molecules which can displace a drug from albumin binding sites.
3. Drugs administered by the oral route show the following characteristics:
a. T
b. T
c. F: the small intestine is the major site of absorption for all drugs due to its much larger surface area for absorption and the high rate of intestinal blood flow.
d. F: generally, a basic drug is more soluble in acid pH than in alkaline pH.
4. The apparent volume of distribution of a drug:
a. F: it is a useful proportionality constant which indicates the relative distribution of a drug between plasma and its potential binding sites.
b. T
c. T: the longer the half-life, the greater the amount of drug present in the body.
d. T
5. Acetylcholine:
a. T
b. T
c. T
d. T: binds to M2 muscarinic receptors which couple with Gi and Gk leading to activation of potassium channels with consequent hyperpolarization of cardiac myocytes.
6. D-tubocurarine:
a. F: is a quarternary amine, therefore poorly absorbed.
b. T: at higher doses, cause blockade by occlusion of open ion channels.
c. T: increase acetylcholine concentration at junctional cleft to displace D-tubocurarine from the nicotinic sites.
d. T
7. Propranolol:
a. F: is a pure antagonist.
b. F: is a non-specific beta blocker.
c. T: due to blockade of beta2 blockers in bronchial smooth muscle.
d. T
8. Histamine causes:
a. T
b. T
c. T
d. T
9. The following are physiological antagonists of histamine acting on bronchial smooth muscle:
a. T
b. T
c. F
d. F
10. Antihistamines antagonize histamine action by:
a. F
b. T
c. F
d. F