Psychiatric Drugs and Medications Q 14
Which group of drugs mimics parasympathetic activity?
A. Cholinergic agents
B. Anticholinergic agents
C. Adrenergic agents
D. Antiadrenergic agents
Correct Answer: A. Cholinergic agents
Cholinergic drugs mimic the effects of the parasympathetic nervous system. Cholinergic medications are a category of pharmaceutical agents that act upon the neurotransmitter acetylcholine, the primary neurotransmitter within the parasympathetic nervous system (PNS). There are two broad categories of cholinergic drugs: direct-acting and indirect-acting. The direct-acting cholinergic agonists work by directly binding to and activating the muscarinic receptors. Indirect-acting cholinergic agents increase the availability of acetylcholine at the cholinergic receptors.
Option B: Anticholinergic agents antagonize the parasympathetic nervous system. Anticholinergic medications are competitive antagonists of the neurotransmitter acetylcholine at receptor sites within the cholinergic system. The cholinergic system utilizes two types of receptors, the plasma membrane-bound G protein-coupled muscarinic receptors, and the ligand-gated ion channel nicotinic receptors. Nicotinic receptors are found in the postganglionic dendrites and nerve bodies of the autonomic nervous system and on the motor endplate of the neuromuscular junction. Muscarinic receptors are present on the target organ cells of the parasympathetic nervous system and sweat glands in the sympathetic nervous system.
Option C: Adrenergic agents stimulate the sympathetic nervous system. Adrenergic drugs are a broad class of medications that bind to adrenergic receptors throughout the body. These receptors include: alpha-1, alpha-2, beta-1, beta-2, beta-3. Adrenergic drugs will bind directly to one or more of these receptors to induce various physiologic effects.
Option D: Antiadrenergic agents block the effect of the sympathetic nervous system. Antiadrenergic agents inhibit the activity of the sympathetic nervous system. They act by blocking adrenergic receptors in target organs or by inhibiting the synthesis, storage, or release of endogenous. Catecholamines (mainly norepinephrine). This class of medications is most commonly used for the treatment of ischemic heart disease and hypertension, although antiadrenergic agents may also be used for urinary retention secondary to benign prostatic hyperplasia and for psychiatric conditions such as anxiety disorders and post-traumatic stress disorder.