Adult: 0.1-0.25 mg/kg (approx 10-20 mg), w/ or preceded by atropine sulfate.
Oral Myasthenia gravis
Adult: 30-120 mg in divided doses, up to a total daily dose of 0.3-1.2 g. Child: <6 yr Initially, 30 mg; 6-12 yr Initially, 60 mg. Doses are repeated throughout the day up to a usual total daily dose of 30-360 mg, w/ increments of 15-30 mg daily until a satisfactory response is obtained.
Oral Paralytic ileus and postoperative urinary retention
Adult: 60-240 mg daily. Child: 15-60 mg daily.
Renal Impairment
Lower initial dose may be needed, titrate to desired effect.
Monitor cholinergic reaction particularly in IV admin.
Overdosage
Symptoms: Cholinergic crisis characterised by severe muscarinic (e.g. nausea and vomiting, diarrhoea) and nicotinic symptoms (e.g. muscle weakness); electrolyte abnormalities. CNS symptoms (e.g. agitation, restlessness, confusion) may occur in extremely high doses. Death may result from CV and resp failure. Management: Maintain adequate respiration. Artificial respiration should be instituted in severe resp depression. Administer 1-4 mg of atropine sulfate IV, w/ additional doses given every 5-30 min as needed.
Drug Interactions
May exacerbate night vision problems w/ anti-glaucoma drugs. Antagonises the effect of non-depolarising muscle relaxants (e.g. pancuronium, vecuronium). Prolongs the effect of depolarising muscle relaxants (e.g. suxamethonium).
Action
Description: Mechanism of Action: Pyridostigmine bromide facilitates impulse transmission across the myoneural junction by inhibiting the destruction of acetylcholine by acetylcholinesterase. It also has direct cholinomimetic effect on skeletal muscles. Onset: 30-45 min (oral); w/in approx 15 min (IM); 2-5 min (IV). Duration: 3-6 hr (oral); 2-3 hr (IV). Pharmacokinetics: Absorption: Poorly absorbed from the GI tract. Bioavailability: 10-20% (oral). Time to peak plasma concentration: Approx 1-3 hr (oral). Distribution: Crosses the placenta and enters breast milk; poor penetration into CNS. Volume of distribution: Approx 19 L. Metabolism: Undergoes hepatic metabolism and hydrolysis by cholinesterases. Excretion: Via urine as unchanged drug and metabolites. Elimination half-life: 3 hr (oral); approx 1.5 hr (IV).
Chemical Structure
Pyridostigmine bromide Source: National Center for Biotechnology Information. PubChem Database. Pyridostigmine bromide, CID=7550, https://pubchem.ncbi.nlm.nih.gov/compound/Pyridostigmine-bromide (accessed on Jan. 22, 2020)
N07AA02 - pyridostigmine ; Belongs to the class of anticholinesterase. Used as parasympathomimetics.
References
Anon. Pyridostigmine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 31/07/2015.Buckingham R (ed). Pyridostigmine Bromide. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 31/07/2015.McEvoy GK, Snow EK, Miller J et al (eds). Pyridostigmine Bromide. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 31/07/2015.Regonol Injection, Solution (Sandoz Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 31/07/2015.