Myasthenia Gravis
- PO (Adults ): Tablets/syrup: 30–60 mg every 3–4 hr initially; then adjusted as required; usual maintenance dose is 600 mg/day in divided doses (range 60–1500 mg/day). Extended-release tablets: 180–540 mg 1–2 times daily (dosing interval should be at least 6 hr; may be associated with ↑ risk of cholinergic crisis; concurrent immediate-release products may be required).
- PO (Children ): 7 mg/kg (200 mg/m2)/day in 5–6 divided doses.
- IM IV (Adults ): 2 mg (1/30 of oral dose); may be repeated every 2–3 hr. During labor/delivery: 1 mg before second stage of labor is complete.
- IM (Neonates Born to Myasthenic Mothers): 50–150 mcg/kg every 4–6 hr.
Antidote for Nondepolarizing Neuromuscular Blocking Agents
- IV (Adults ): 10–20 mg; pretreat with 0.6–1.2 mg atropine IV.
