II. Mechanism: Muscarinic Antagonists
- M1, M4, M5 Receptor Antagonist (CNS Effects)
- M2 Receptor Antagonist (Cardiac Effects)
- Increased AV Nodal Conduction (Tachycardia, Arrhythmias)
- M3 Receptor Antagonist (Smooth Muscle and Exocrine Glands)
III. Mechanism: Nicotinic Antagonists
-
Ganglionic Blocking Agents (act at Autonomic Nervous System)
- Sympathetic effects
- Vasodilation
- Parasympathetic effects
- Mydriasis
- Decreased gastrointestinal motility and Constipation
- Tachycardia
- Urinary Retention
- Sympathetic effects
- Neuromuscular Blocking Agents (act at Neuromuscular Junction)
- Background
- Acetylcholine acts at the Neuromuscular Junction (NMJ) with 2 of 5 receptor sites specific for Acetylcholine binding
- When both Acetylcholine receptors are bound, ion channels open allowing Sodium influx and Membrane Depolarization
- Resulting impulse triggers muscular contraction
- Nondepolarizing Neuromuscular Blocking Agent (Vecuronium, Rocuronium)
- Acetylcholine Competitive Receptor Antagonists
- Inhibited Muscle Contraction (Muscle relaxation, paralysis)
- Depolarizing Neuromuscular Blocking Agent (Succinylcholine)
- Competitive Cholingergic Agonist
- Succinylcholine is an Agonist that binds and blocks Acetylcholine from binding until it dissociates from receptor site
- Transient muscle Fasciculations and contractions (due to Agonist activity), followed by paralysis
- Background
IV. Medications: Muscarinic Antagonists
- Background
- Agents listed here are specifically indicated for their Anticholinergic activity
- Contrast with other agents with Anticholinergic activity as an adverse effect (e.g. Antihistamines, Tricyclic Antidepressants)
- Belladona Alkaloids
- Atropine
- Prototypal CholinergicAntagonist against which other agents are compared
- Extracted from plants such as deadly nightshade (atropa belladona)
- Used in Unstable Bradycardia and Bladder spasms (e.g. B&O suppositories)
- Scopolamine
- Used in Motion Sickness and perioperative Nausea and Vomiting
- Hyoscyamine (Levsin)
- Used as a gastrointestinal antispasmodic agents
- Atropine
- Synthetic tertiary agents
- Gastrointestinal Antispasmodic Agents
- Dicyclomine (Bentyl)
- Mebeverine
- Oxyphencyclimine
- Trimebutine
- Bladder Antispasmodic
- Treatment of Parkinsonism, Extrapyramidal Side Effects and other Movement Disorders
- Trihexylphenidyl (Artane)
- Biperiden (Akineton)
- Procyclidine (Kemadrin)
- Benztropine (Cogentin)
- Ocular (Cycloplegic, Mydriatic)
- Homatropine
- Gastrointestinal Antispasmodic Agents
- Synthetic quaternary agents
- Gastrointestinal Antispasmodic Agents
- Methscopolamine Bromide (Pamine)
- Clidinium (Bromide)
- Glycopyrolate (Robinul)
- Isopropamide
- Methantheline
- Tridihexethyl
- Gastrointestinal Antispasmodic Agents
V. Medications: Neuromuscular Blockers
VI. Complications
- See Anticholinergic Toxicity
-
Altered Level of Consciousness (esp. elderly)
- Delirium or confusion (may mimic Dementia)
- Memory Impairment
- Delirium
- Obtundation
VII. Resources
VIII. References
- Olson (2020) Clinical Pharmacology, Medmaster, Miami, p. 28-9
Images: Related links to external sites (from Bing)
Related Studies
Definition (MSH) | Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system. |
Definition (NCI) | Natural or synthetic Antimuscarinic Agents inhibit acetylcholine neurotransmitter action at muscarinic receptors. Antimuscarinic drugs are used as antiarrhythmic, antiparkinson, antiasthmatic, and antispasmodic agents, as well as antidote of the natural mushroom alkaloid muscarine (Amanita muscaria) or to prevent parasympathetic stimulation at neuroeffector junctions. (NCI04) |
Concepts | Pharmacologic Substance (T121) |
MSH | D018727 |
SnomedCT | 349944005, 26244009, 372679000 |
English | Agents, Antimuscarinic, Antimuscarinic Agents, Antagonists, Muscarinic, MUSCARINIC ANTAG, Muscarinic Cholinergic Antagonist, Muscarinic Antagonist, Antimuscarinics, antimuscarinic agent, antimuscarinic, antimuscarinics, muscarinic antagonist, muscarinic antagonists, Muscarinic Antagonists, Muscarinic Antagonists, Cholinergic, Cholinergic Muscarinic Antagonists, Antagonists, Cholinergic Muscarinic, Antimuscarinic, Antimuscarinic (product), Antimuscarinic (substance), Antimuscarinic, NOS, Antimuscarinic Agent |
French | Antimuscariniques, Agents antimuscariniques, Médicaments antimuscariniques, Antagonistes muscariniques, Anti-muscariniques |
Swedish | Muskarinblockerare |
Czech | muskarin - antagonisté |
Finnish | Muskariiniantagonistit |
Italian | Agenti antimuscarinici, Antagonisti muscarinici |
Russian | ANTIMUSKARINOVYE SREDSTVA, MUSKARINOVYE ANTAGONISTY, MUSKARINA ANTAGONISTY, АНТИМУСКАРИНОВЫЕ СРЕДСТВА, МУСКАРИНА АНТАГОНИСТЫ, МУСКАРИНОВЫЕ АНТАГОНИСТЫ |
Japanese | 抗ムスカリン作動剤, ムスカリン拮抗剤, 抗ムスカリン作用物質, ムスカリンアンタゴニスト, 抗ムスカリン作用剤 |
Polish | Środki przeciwmuskarynowe, Antagoniści muskaryny |
Croatian | MUSKARINSKI ANTAGONISTI |
Spanish | Antimuscarínicos, antimuscarínico (producto), antimuscarínico (sustancia), antimuscarínico, Agentes Antimuscarínicos, Antagonistas Muscarínicos |
Portuguese | Antimuscarínicos, Agentes Antimuscarínicos, Antagonistas Muscarínicos |
German | Antimuscarinika, Muscarinantagonisten |
Ontology: Anticholinergic Agents (C0242896)
Definition (CHV) | a drug used to relieve cramps or spasms of the stomach, intestines, and bladder |
Definition (CHV) | a drug used to relieve cramps or spasms of the stomach, intestines, and bladder |
Definition (CHV) | a drug used to relieve cramps or spasms of the stomach, intestines, and bladder |
Definition (CHV) | a drug used to relieve cramps or spasms of the stomach, intestines, and bladder |
Definition (CHV) | a drug used to relieve cramps or spasms of the stomach, intestines, and bladder |
Definition (CHV) | a drug used to relieve cramps or spasms of the stomach, intestines, and bladder |
Definition (NCI) | Any agent that binds to and blocks nicotinic and/or muscarinic receptors, thereby preventing the actions of the neurotransmitter acetylcholine (Ach) at these receptors. |
Definition (CSP) | group of drugs that bind to but do not activate cholinergic receptors, thereby blocking the actions of acetylcholine or cholinergic agonists. |
Concepts | Pharmacologic Substance (T121) |
MSH | D018680 |
SnomedCT | 14601000, 373246003 |
LNC | LP31390-5 |
English | Agents, Anticholinergic, anticholinergic agent, Anticholinergics, Anticholinergic Agent, anticholinergics (medication), anticholinergics, anticholinergic drugs, anticholinergic drug, anticholinergic, anticholinergic agents, Anticholinergic Agents, Cholinergic Anatagonist, ANTICHOLINERGIC AGENTS, Anti Cholinergics, Anti-Cholinergics, Anticholinergic, Anticholinergic agent (product), Anticholinergic agent (substance), Anticholinergic agent, Anticholinergic agent, NOS, Anticholinergic Drugs |
French | Agents anticholinergiques, Médicaments anti-cholinergiques, Médicaments anticholinergiques, Anti-cholinergiques, Anticholinergiques |
Portuguese | Agentes Anticolinérgicos |
Spanish | Agentes Anticolinérgicos, agente anticolinérgico (producto), agente anticolinérgico (sustancia), agente anticolinérgico |
German | Anticholinergika |
Ontology: Nicotinic Antagonists (C0242956)
Definition (NCI) | Natural or synthetic compounds inhibiting acetylcholine neurotransmitter action at nicotinic receptors, which are ionotropic receptors that form ligand-gated ion channels in cells' plasma membranes. |
Definition (MSH) | Drugs that bind to nicotinic cholinergic receptors (RECEPTORS, NICOTINIC) and block the actions of acetylcholine or cholinergic agonists. Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses. |
Concepts | Pharmacologic Substance (T121) |
MSH | D018733 |
English | Antagonists, Nicotinic, Nicotinic Antagonists, NICOTINIC ANTAG, Nicotinic Antagonist, Nicotinic Cholinergic Antagonist, Nicotinic Receptor Antagonist, nicotinic antagonist, antagonist nicotinic |
French | Médicaments antinicotiniques, Agents antinicotiniques, Antinicotiniques, Antagonistes nicotiniques, Anti-nicotiniques |
Swedish | Nikotinblockerare |
Czech | receptory nikotinové - antagonisté |
Finnish | Nikotiiniantagonistit |
Russian | NIKOTINOVYE ANTAGONISTY, НИКОТИНОВЫЕ АНТАГОНИСТЫ |
Polish | Antagoniści nikotyny |
German | Nicotinantagonisten |
Italian | Antagonisti nicotinici |
Portuguese | Antagonistas Nicotínicos |
Spanish | Antagonistas Nicotínicos |