Pyridostigmine: Uses, Interactions and Safety
Uses
Pyridostigmine is a reversible cholinesterase inhibitor that prolongs acetylcholine activity. It improves muscle strength in myasthenia gravis. The reviewed UK and Turkish products also include paralytic ileus and postoperative urinary retention; the Turkish document additionally lists atonic constipation. These uses do not apply when a mechanical obstruction is present.
Administration
This summary concerns immediate-release oral tablets taken with water. Timing is individualized around the periods when muscle strength is needed. Kidney impairment can reduce the amount required. Extended-release tablets and injections have different instructions and should not be exchanged using this page.
Safety
Mechanical gastrointestinal or urinary obstruction and relevant allergy are contraindications. Asthma, COPD, slow heart rhythm, AV block, low blood pressure and peptic ulcer need special caution. Both worsening myasthenia and excessive cholinergic treatment can cause increasing weakness, but their management differs. New breathing or swallowing difficulty, severe weakness, fainting or marked secretions needs emergency assessment. Do not respond by increasing the medicine yourself.
Interactions
Corticosteroids and immunosuppressants can reduce the requirement for pyridostigmine as disease control improves. Starting a corticosteroid can initially worsen myasthenia, so changes need supervision. Antimuscarinics can oppose its muscarinic effects and alter gastrointestinal absorption; they may sometimes be deliberately prescribed to control side effects and should not automatically be described as forbidden. Other cholinergic medicines can increase adverse effects. Some antibiotics, antiarrhythmics and anaesthetic or muscle-relaxant drugs interfere with neuromuscular transmission. Tell the anaesthetist about treatment before a procedure.
Pregnancy and breastfeeding
Pregnancy experience is available but safety is not fully established. Disease activity and treatment needs can change during pregnancy; excessive dosing should be avoided and the newborn assessed as needed. Milk transfer is small, but possible infant effects still deserve attention.
Adverse effects
Nausea, diarrhea, cramps, sweating, increased saliva or bronchial secretions and muscle twitching can occur. Their frequencies are not reliably established. Visual accommodation changes can impair driving. Increased weakness alongside these symptoms warrants prompt clinical review.
Sources
The linked Turkish profile contains the medicine record and its documented interaction list.