Physostigmine, Eserine

Central anticholinergia; used for diagnosis and treatment in patients with a Hx of anticholinergic ingestion and/or exposure: Atropine, scopolamine, belladonna, jimson weed, toxic mushrooms, tricyclics, phenothiazines, antihistamines, benzodiazepines, opiates, inhalation anesthetics, propofol, GHB.

• “Blind as a bat”: Mydriasis and loss of accommodation

• “Dry as a bone”: Urinary retention and dry mucous membranes

• “Hot as a hare”: Hyperthermia from loss due to sweating

• “Red as a beet”: Cutaneous vasodilation; counteracts hyperthermia

• “Mad as a hatter”: Fluctuating consciousness, delirium, disorientation, decreased social restraint, slurred speech, incoordination, hallucinations, phantom behaviors, coma, paranoia during recovery

Postop delirium from agitation to excessive somnolence. Best indication for treatment of combined central and peripheral anticholinergia.

Glaucoma, ciliary muscle contraction = miosis = facilitates outflow of aqueous humor.

Treatment for antimuscarinic xenobiotic toxicity (a chemical compound that is foreign to a living organism; e.g., benzodiazepines, tricyclics, antihistamines, jimson weed).

Reversal of NMB (neostigmine a better choice as it avoids CNS effects).

Hereditary ataxias.

Alzheimer disease (may improve short-term memory but not used clinically).

Analgesia (decreases morphine consumption postop).

Cholinesterase inhibition = excess acetylcholine. Can lead to three sets of problems: Analogous to organophosphorus compound poisoning, a cholinergic crisis (basically the opposite of anticholinergia syndrome above)

• Muscarinic cholinergic (parasympathetic) over-stimulation (DUMBELS): D = Defecation, diarrhea, diaphoresis, GI distress; U = urination; M = miosis; B = bronchorrhea, bronchospasm, bradycardia; E = emesis (nausea); L = lacrimation; S = salivation

• Nicotinic cholinergic excess (continuing depolarization of motor endplate, leading to fasciculations at low doses and progressive weakness at high doses)

• CNS (anxiety, confusion, tremors, seizures, respiratory depression, coma)

Reactive airway disease

Peripheral vascular disease

Diabetes

Bowel or bladder obstruction

Preexisting intraventricular conduction delay, long-QT syndrome

Preexisting AV block

Pregnancy (class C)

Sulfite allergy (contains sodium bisulfite preservative)