Can cause excess Ach with a Cholinergic crisis/syndrome. Avoid with asthma
- Useful for those who are weak on waking
Mode of action
- Less potent than neostigmine but longer action
- Inhibit action of acetylcholinesterase which prolongs the action of Ach
- In excess can impair action and worsen weakness
- It can precipitate cholinergic crises by causing a depolarising block.
- This may be difficult to distinguish from a worsening myasthenic state.
Dose range: Monitor LFTs
|Pyridostigmine (Myasthenia) ||30-120 mg||QDS||PO. Try not to exceed 450 mg/day. Higher doses 1.2 g/day used. |
Consider Immunosuppression if dose > 360 mg/day
- Asthma (extreme caution), bradycardia, arrhythmias, recent MI
- Epilepsy, hypotension, parkinsonism, peptic ulceration, hyperthyroidism
- Bowel/Urinary obstruction
- Pronounced muscarinic action - sweating, colic, excessive salivation, or diarrhoea, excess gastric secretions, bradycardia.
- Can be reverse with Atropine like drugs.