Pyridostigmine

Indications

Pyridostigmine is used for: Reversal of neuromuscular blockade, Myasthenia gravis, Paralytic ileus, post-operative urinary retention

Adult Dose

Oral Myasthenia gravis Adult: 30-120 mg in divided doses, up to a total daily dose of 0.3-1.2 g. Paralytic ileus and postoperative urinary retention Adult: 60-240 mg daily.

Child Dose

Oral Myasthenia gravis 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. Paralytic ileus and postoperative urinary retention Child: 15-60 mg daily.

Renal Dose

Renal impairment: Lower initial dose may be needed, titrate to desired effect.

Administration

Should be taken with food.

Contra Indications

Mechanical GI or urinary obstruction.

Precautions

Patient w/ bronchial asthma, COPD, bradycardia, cardiac arrhythmias, vagotonia, peptic ulcer, epilepsy or parkinsonism, hyperthyroidism. Renal impairment. Childn. Pregnancy and lactation. Monitoring Parameters Monitor cholinergic reaction particularly in IV admin.

Pregnancy-Lactation

Pregnancy Category: B Lactation: Compatible

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).

Adverse Effects

Side effects of Pyridostigmine : Nausea, vomiting, diarrhoea, increased peristalsis and bronchial secretions, miosis, excessive salivation and sweating, abdominal cramps, bradycardia, bronchospasm, skin rash, muscle spasm, fasciculation, muscle weakness. Potentially Fatal: Resp paralysis, cardiac arrest, pulmonary oedema.

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.