1. All of the following are general mechanisms of drug permeation Except
2. If the plasma concentration of a drug declines with “first-order kinetics”, this means that
3. Regarding termination of drug action
4. Distribution of drugs to specific tissues
5. A physical process by which a weak acid becomes less water-soluble and more lipid-soluble at low pH is
6. Substance secreted into the blood by a neuron is
Neurohormone: a hormone such as vasopressin or noradrenaline produced by nerve cells and secreted into the circulation while neurotransmitter is a substance present in neuron and is secreted by neurons to transmit signals to its postsynaptic targets.
7. 2. Which of the following drugs is correctly associated with its site of action and maximal diuretic efficacy?
8. cAMP is an example of
An example of neuromodulator is cAMP. It acts as a second messenger of synaptic transmission
9. Which of the following is a leukotriene receptor blocker?
Zafirlukast is a leukotriene receptor blocker
10. A molecule that stimulates nitric oxide synthase, especially the eNOS isoform, is
11. If phenelzine is administered to a patient taking fluoxetine, the most likely result is
12. Suramin is an antagonists of ________receptors
Suramin is an antagonist of purinergic receptors, specifically P2x and P2y
13. Induction of various forms of synaptic plasticity is more closely associated with ______ receptors
NMDA receptors are closely associated with the induction of synaptic plasticity. AMPA and kainite receptors are involved in mediation of fast depolarization.
14. Following is GABAA agonist
Muscimol is GABAA agonist. Baclofen is a GABAB agonist. Bicuculline is a GABAA antagonist
15. Thiamine is vitamin
Thiamine is vitamin B1 and was the first member of vitamin B complex to be identified. Vitamin B6 – Pyridoxine, pyridoxal and pyridoxamine. Medically used vitamin B12 is hydroxycobalamine. Vitamin B2 is riboflavin
16. in adults, approximately ______ mg of thiamine per day is completely degraded by the tissue
In adults, approximately 1 mg of thiamine per dayis completely degraded by the tissues and 1mg is roughly the minimal daily requirement of thiamine.
17. Conversion of methionine to cysteine depends on vitamin
Conversion of methionine to cysteine depends on vitamin B6. Vitamin B1, B2 and B12 do not play any role in this conversion. Vitamin B6 is also involved in various metabolic transformations of amino acids e.g. decarboxylation, transamination and racemization.
18. Avidin, a protein found in egg white is an antagonist of
Avidin, a protein found in egg white, is an antagonist of biotin. Avidin is a glycoprotein and it binds with biotin with great affinity and thus prevents its absorption.
19. Physiologically carnitine plays following role
Carnitine has several physiological roles: • It is important for oxidation of fatty acids. • It increases aerobic metabolism of carbohydrates. • It increases rate of oxidative phosphorylation. • It enhances the excretion of certain organic acids.
20. 1. â-Aminoethylimidazole is?
β-Aminoethylimidazole is a chemical name of histamine
21. Vasodilation by prostaglandins involves
Prostaglandins are potent vasodilators and this action involves arterioles, precapillary sphincters and postcapillary venules. Prostaglandins have no effect on large veins.
22. Instead of being effective in hyperuricaemia following drug is contradictred in the treatment of gout
Aspirin (in general salicylates) are contraindicated in the treatement of gout as they elevate uric acid levels and they also antagonize the actions of probenecid and sulfinpyrazone. Indomethacin, diclofenac and piroxicam have no such effects and hence are not contraindicated.
23. Following mediators are involved in acute inflammation except
Histamine, leukotrienes and bradykinin are mediators of acute inflammation. Interferons are involved in chronic inflammatory conditions.
24. Histamine induced edema results from the action on _____ receptors
Histamine induced edema results from the action of H1 receptors. This H1 receptor effect results in outward passage of plasma protein and fluid from capillaries into extracellular spaces and increase in the flow of lymph and its protein content. H2 and H3 receptors are not involved in these effects.
25.Enhanced automaticity in cardiac cells may occur because of
β-Adrenergic stimulation, hypokalemia and mechanical stretch produce increase in phase 4 slope, leading to acceleration of pacemaker rate, which results in enhanced automaticity.
26. In cardiac cells, adenosine
n cardiac cells, adenosine acts on its specific membrane receptors and activates acetylcholinesensitive potassium current, specifically in atrium, sinus and AV node. This results in shortening of action potential duration. Activation of potassium current also results in hyperpolarization and slowing of automaticity.
27.Following statement is true about lidocaine
Lidocaine blocks both open and inactivated cardiac sodium channels. It decreases automaticity mainly by reducing the slope of phase 4 and alters the threshold for cardiac excitability. Lidocaine may shorten the duration of action potential because of blockade of sodium channels, which get inactivated late during action potential,
28. Following potassium sparing diuretic is a mineralocorticoid receptor antagonist
Spironolactone is an aldosterone antagonist. Aldosterone is a mineralocorticoid and mineralcorticoid receptors are present in epithelial cells of late distal tubule and collecting duct.
29. . Following is a phenothiazine analog with sodium channel blocking properties
Moricizine is a phenothiazine analogue with sodium channel blocking activity and is used in the treatment of ventricular arrhythmias. Mexiletine and tocainide are analogous of lidocaine. Propafenone has some structural similarities to propranolol.
30. Effect of decreased vitamin K on action of warfarin is
Warfarin acts as an anticoagulant by inhibiting enzymatic reduction of vitamin K to its active hydroquinone form and the inhibition is competitive. Thus, if there are decreased levels of vitamin K obviously there will be less competition for inhibition resulting in enhanced anticoagulatory effect of warfarin.