Tricyclic antidepressants are:

Correct Answer: D

Rationale: Tricyclic antidepressants inhibit the reuptake of both norepinephrine and serotonin in the brain, making them mixed norepinephrine and serotonin reuptake inhibitors. This mechanism contributes to their antidepressant effects. Options A and C are incorrect as tricyclic antidepressants are not highly selective for either serotonin or norepinephrine reuptake. Option B is incorrect as tricyclic antidepressants are not monoamine oxidase inhibitors. Thus, the correct answer is D due to the dual mechanism of action of tricyclic antidepressants on norepinephrine and serotonin reuptake.

Correct Answer: C

Rationale: The correct answer is C because psychosis with visual and auditory hallucinations is not a common characteristic of cocaine abstinent syndrome. A: Feeling of depression, irritability, confusion, insomnia in the initial days is common due to withdrawal symptoms. B: Depression, apathy, excessive appetite, and the wish to sleep in the subsequent days are typical withdrawal symptoms. D: A new attack of depression, anxiety, irritability, dullness, and intense thirst for cocaine after initial improvement is consistent with the stages of cocaine abstinent syndrome.

Correct Answer: B

Rationale: The correct answer is B: Tachycardia. Non-selective beta2-adrenomimics stimulate both beta1 and beta2 adrenergic receptors, leading to increased heart rate (tachycardia) due to beta1 receptor activation. A: Depression of the breathing centre is not a side effect of non-selective beta2-adrenomimics. C: Peripheral vasoconstriction is more commonly associated with alpha-adrenergic agonists, not beta2-adrenomimics. D: Dry mouth is not a common side effect of beta-adrenergic stimulation.

Correct Answer: B

Rationale: The correct answer is B: Folic acid. Folic acid is not a drug used for iron deficiency anemia; it is a B-vitamin essential for normal cellular function but not directly related to iron supplementation. Ferrous sulfate, ferrous gluconate, and ferrous fumarate are all iron salts commonly used to treat iron deficiency anemia by replenishing the body's iron stores. Folic acid, on the other hand, is primarily used to prevent neural tube defects in pregnancy and to treat certain types of anemia not related to iron deficiency.

Correct Answer: C

Rationale: Amrinone inhibits breakdown of cAMP by inhibiting phosphodiesterase enzyme in vascular smooth muscle. This leads to increased cAMP levels, causing vasodilation. Digoxin, dobutamine, and dopamine have no direct effect on cAMP breakdown in vascular smooth muscle. Digoxin increases intracellular calcium, dobutamine is a beta-adrenergic agonist, and dopamine acts on dopamine receptors.