Medical Pharmacology Chapter 6: Autonomic Pharmacology: Cholinergic Drugs
Management of reflex bradycardia
Use in antagonism of nondepolarizing neuromuscular-blocking agents
Common Applications-- anesthesia related (anticholinergic agents)
Management of reflex bradycardia
Combinations with anticholinesterase agents during pharmacological antagonism of nondepolarizing neuromuscular-blocking agents
Other Applications of anticholinergic drugs:
Biliary/ureteral smooth muscle relaxation
Inhibition of parietal cells acid secretion
Prevention of motion sickness (nausea)
Component in cold remedies
In normal doses, atropine produces little CNS effect.
In toxic doses, CNS excitation results in restlessness, hallucinations, and disorientation.
At very high doses, atropine can lead to CNS depression which causes circulatory and respiratory collapse.
By contrast, scopolamine at normal therapeutic doses causes CNS depression, including drowsiness, fatigue and amnesia.
Scopolamine also may produce euphoria, a basis for some abuse potential.
Scopolamine may exhibit more CNS activity than atropine because scopolamine crosses the blood brain barrier more readily.
Antimuscarinics are used clinically as preanesthetic medication to reduce vagal effects secondary to visceral manipulation during surgery.
Antimuscarinics with L-DOPA are used in Parkinson's disease.
Extrapyramidal effects induced by some antipsychotic drugs may be treated with antimuscarinic agents.
Scopolamine (transdermal) is effective in preventing motion sickness.
Atropine is also an effective antidote to excessive cholinergic stimulation following organophosphate intoxication.
By blocking muscarinic receptors, the consequences of cholinesterase inhibition is attentuated.
Atropine may be used in conjunction with 2-PAM which may reactivate phosphorylated, inhibited acetylcholinesterase by nucleophilic displacement.
Taylor, P. Agents Acting at the Neuromuscular Junction and Autonomic Ganglia In, Goodman and Gillman's The Pharmacologial Basis of Therapeutics,(Hardman, J.G, Limbird, L.E, Molinoff, P.B., Ruddon, R.W, and Gilman, A.G.,eds) The McGraw-Hill Companies, Inc.,1996, pp.193-195. Adapted from Table 9-3.
This Web-based pharmacology teaching site is based on reference materials, that are believed reliable and consistent with standards accepted at the time of development. Possibility of human error and on-going research and development in medical sciences do not allow assurance that the information contained herein is in every respect accurate or complete. Users should confirm the information contained herein with other sources. This site should only be considered as a teaching aid for undergraduate and graduate biomedical education and is intended only as a teaching site. Information contained here should not be used for patient management and should not be used as a substitute for consultation with practicing medical professionals. Users of this website should check the product information sheet included in the package of any drug they plan to administer to be certain that the information contained in this site is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. Advertisements that appear on this site are not reviewed for content accuracy and it is the responsibility of users of this website to make individual assessments concerning this information. Medical or other information thus obtained should not be used as a substitute for consultation with practicing medical or scientific or other professionals.