Pyridostigmine

Administration

• Type: Neostimine analogue, cholinesterase inhibitor
• Dosage Forms: oral immediate or extended release, IV
• Routes of Administration: IV, PO
• Common Trade Names:
• As opposed to physostigmine, pyridostigmine does not cross the blood brain barrier, and is thus a poor agent for agitation and CNS complications

Adult Dosing

• Myasthenia gravis: 60-1500 mg PO daily (immediate release) or 180-540mg PO daily (slow-release)
• Reversal of neuromuscular blocking agents: 0.1-0.25 mg/kg IV
• Organophosphate poisoning prophylaxis: 30mg PO q8h

Special Populations

• Pregnancy Rating: C
• Lactation risk: Infant risk minimal
• Renal dosing: lower dose may be required, titrate to effect

Contraindications

• Allergy to class/drug
• Mechanical bowel or urinary obstruction

Adverse Reactions

Serious

• Cholinergic crisis
• Bradyarrythmia

Common

• Nausea/vomiting, abdominal cramps, diarrhea
• Muscle cramps, fasciculation, asthenia
• Increased bronchial and salivary secretions

Pharmacology

• Half-life: 3 minutes (IV), 200 minutes (oral)
• Metabolism:
• Excretion: Renal

Mechanism of Action

• Neostigmine analogue; competitive cholinesterase inhibitor→ less acetylcholine breakdown→ more available acetylcholine in synapses

See Also

• Neostigmine
• Neuromuscular blocking agents
• Myasthenia gravis