II. Mechanism: Muscarinic Antagonists

  1. M1, M4, M5 Receptor Antagonist (CNS Effects)
    1. Altered Mental Status
  2. M2 Receptor Antagonist (Cardiac Effects)
    1. Increased AV Nodal Conduction (Tachycardia, arrhythmias)
  3. M3 Receptor Antagonist (Smooth Muscle and Exocrine Glands)
    1. Decreased gastrointestinal motility
    2. Decreased Salivation
    3. Decreased Bladder contractions and increased Urethral sphincter tone
    4. Bronchodilation and decreased Bronchial secretions
    5. Mydriasis
    6. Decreased sweating

III. Mechanism: Nicotinic Antagonists

  1. Ganglionic Blocking Agents (act at Autonomic Nervous System)
    1. Sympathetic effects
      1. Vasodilation
    2. Parasympathetic effects
      1. Mydriasis
      2. Decreased gastrointestinal motility and Constipation
      3. Tachycardia
      4. Urinary Retention
  2. Neuromuscular Blocking Agents (act at neuromuscular junction)
    1. Acetylcholine Competitive Receptor Antagonists (Vecuronium, Rocuronium)
      1. Inhibited muscle contraction (muscle relaxation, paralysis)
    2. Depolarizing Antagonists (Succinylcholine)
      1. Transient muscle fasciculations and contractions, followed by paralysis

IV. Complications

  1. See Anticholinergic Toxicity
  2. Altered Level of Consciousness (esp. elderly)
    1. Delirium or confusion (may mimic Dementia)
    2. Memory Impairment
    3. Delirium
    4. Obtundation

V. Preparations: Muscarinic Anticholinergic effects (most Anticholinergic first)

  1. Atropine (100% of maximal Anticholinergic effect)
  2. Scopolamine
  3. Tolterodine
  4. Hyoscyamine
  5. Cholinergic Parkinsonism agents
    1. Trihexyphenidyl
    2. Benztropine
  6. Prednisone (55%)
  7. Diphenhydramine (Benadryl)
  8. Amitriptyline (Elavil)
  9. Digoxin
  10. Nifedipine
  11. Phenobarbital
  12. Oxybutynin (20%)
  13. Isosorbide Dinitrate
  14. Hydroxyzine
  15. Warfarin
  16. Dipyridamole
  17. Codeine
  18. Ranitidine (10%)
  19. Dyazide
  20. Furosemide (Lasix)
  21. Nortriptyline (3%)

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Related Studies

Ontology: Muscarinic Antagonists (C0003385)

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