Anticholinergics Flashcards
_______________ is the most common overdose that produces anticholinergic toxicity
Antihistamine (particularly diphenhydramine) overdose
With oral ingestion, the onset of anticholinergic toxicity usually occurs within ___________
1 to 2 hours
Cholinergic receptors exist as two major subtypes:
muscarinic receptors and nicotinic receptors
are found predominantly on autonomic effector cells that are innervated by postganglionic parasympathetic nerves, on some ganglia, and in the brain, particularly the hippocampus, cortex, and thalamus.
Muscarinic receptors
are found at peripheral autonomic ganglia, at neuromuscular junctions, and also in the brain.
Nicotinic receptors
is the neurotransmitter that modulates both receptor types.
Acetylcholine
is the neurotransmitter that modulates both receptor types.
Acetylcholine
Anticholinergic drugs and plant toxins mechanism of action
competitively inhibit or antagonize the binding of the neurotransmitter acetylcholine to muscarinic acetylcholine receptors.
The term anticholinergic is technically a misnomer because
A more accurate term is antimuscarinic agents, because anticholinergic agents do not antagonize effects at nicotinic acetylcholine receptors such as those at the neuromuscular junction.
The central anticholinergic syndrome refers to
the clinical state when there is predomination of the central effects (fever, agitation, delirium, coma) of muscarinic receptor antagonism.
refers to peripheral muscarinic antagonism’s constellation of findings: tachycardia, flushed dry skin, dry mouth, ileus, and urinary retention.
peripheral anticholinergic syndrome
IV injection of antihistamines, particularly of those (e.g., diphen- hydramine) affecting H1 histamine receptor antagonists, seems to cause euphoria in some patients, explain.
effect may be attributed to the drug’s increasing dopamine levels in the brain’s nucleus accumbens area (which stimulates the reward and motivation system)
True or false
The major therapeutic challenge in the treatment of moderate to severe anticholinergic poisoning involves obtaining adequate control of the agitated individual.
True
True or false
pharmacologic sedation is strongly recommended,
True
Moa of Physostigmine
is a reversible acetylcholinesterase inhibitor (mecha- nistically related to the carbamate insecticides) that crosses the blood– brain barrier due to its lipophilic tertiary ammonium properties.
