Which temporizing therapies can rapidly improve Myasthenia gravis?
Both plasma exchange (PE) and intravenous immunoglobulin (IVIG) induce improvement in most Myasthenia gravis patients within 1 to 2 weeks.
Typical courses of therapy might include six exchanges every other day over 2 weeks, or 400 mg/kg/day of IVIG for 5 days. Improvement usually peaks at 2 to 4 weeks and then gradually abates at 6 to 8 weeks.
These therapies seem to have equivalent efficacy in general, though some patients may respond better to one or the other.
There are no data suggesting that combined therapy is any more beneficial than treatment with either agent alone.
They are helpful when rapid improvement is needed (i.e., myasthenic crisis), to prepare symptomatic patients for steroid induction, and for surgical procedures such as thymectomy.
In rare instances, patients refractory to chronic oral therapies may require indefinite courses of treatment with these temporizing therapies on a regular schedule.
