In the first trial with 87 patients with acute exacerbation of generalized MG, no significant change in muscle strength between day 0 and day 15 was observed between the two treatment groups.69 The second trial with a crossover design of 12 patients with moderate-to-evere MG in a stable phase showed no significant difference between the two groups after 1 and 4 weeks of treatment.70 The Cochrane group reported that an unpublished, randomized controlled trial of intravenous immunoglobulin versus oral methylprednisolone in 33 patients with acute exacerbation of generalized MG failed to demonstrate any significant difference between the two treatment arms.71 Another randomized controlled trial comparing two doses of intravenous immunoglobulin in 173 patients with acute Rabbit polyclonal to IL1B exacerbation of generalized MG did not demonstrate any significant difference in efficacy between the doses of 1 1 g/kg and 2 g/kg.72 There is some evidence that intravenous AL 8697 immunoglobulin is efficacious in acute severe exacerbation of generalized MG, but the evidence is less clear in chronic cases.73 Intravenous immunoglobulin is typically used in acute exacerbation of MG or to optimize muscle strength before surgery. kinase (MuSK), but there are other as yet undiscovered antigens. These AL 8697 antibodies reduce the number of functional AChRs and thus impair neuromuscular transmission. The prevalence of MG has increased from around 5 per million population between 1915 and 19341 to about 200 per million population now,2 in part due to improved detection of the antibodies to the postsynaptic proteins. The estimated annual incidence of MG is between 1 in 10,000 to 1 1 in 50,000 of the population,3 but the clinical recognition of this rare disease remains difficult with many patients going undiagnosed AL 8697 for many months from symptom onset, and the diagnosis only correctly made after several physician consultations. In the past 70 years, treatment advances have reduced the mortality of MG from 70% between 1915 and 19341 to 5% or less now.4 In this review an overview will be given of the mechanism, evidence, indication, and relevant adverse effect profile of the different treatment options in generalized MG. Several potential future therapies will also be discussed. Symptomatic treatment Acetylcholinesterase inhibitors In MG, the first-line option is symptomatic treatment with acetylcholinesterase inhibitors. Pyridostigmine bromide is the most commonly used drug. Other acetylcholinesterase inhibitors such as neostigmine are rarely used because of their poorer pharmacodynamic profiles and tolerability. In an observational study of 14 MG patients comparing pyridostigmine with neostigmine, it was concluded that over 1 year, pyridostigmine was more effective with less adverse events.5 Similar conclusions were reached in another observational study of 69 patients which compared the use of pyridostigmine with neostigmine.6 There is no large randomized controlled trial of acetylcholinesterase inhibitors in MG, but the clear response of this drug in observational studies would make depriving patients in the placebo arm of a randomized controlled trial unethical and unjustifiable.7 Pyridostigmine is most effective early in the course of MG and over time increasing tolerance to the drug develops which may necessitate dose escalation. Most MG patients do not achieve adequate response with acetylcholinesterase inhibitor treatment and will require further immunosuppression. It is also noteworthy that some MuSK antibody-positive patients may show nonresponsiveness to acetylcholinesterase inhibitors. In one study, 71% of MuSK antibody positive patients failed to respond to acetylcholinesterase inhibitors, compared to 18% respectively of AChR antibody positive and seronegative patients.8 Pyridostigmine is generally well tolerated. Adverse events include muscarinic side effects such as nausea, vomiting, abdominal cramping, diarrhea, diaphoresis, increased lacrimation, excessive respiratory secretions, bradycardia, and atrioventricular block. Antimuscarinics such as AL 8697 propantheline bromide provide effective symptomatic relief against the abdominal adverse events induced by pyridostigmine. Pyridostigmine may also cause nicotinic adverse events such as muscle cramps and fasciculations, but these rarely require a change in the dose of the drug. High doses of pyridostigmine may desensitize AChRs and induce weakness resulting in a cholinergic crisis. If there is such a concern, cholinesterase inhibitors need to be temporarily withdrawn and the patient carefully monitored for improvement. Short-term immunosuppression Corticosteroids Corticosteroids are thought to act on the immune system by inhibiting the activation of T-cells and impairing the function of cells of the monocyte/macrophage lineage. Adrenocorticotrophic hormone (ACTH) was first described to have a beneficial effect in MG in 1935. 9 Good improvement was reported in a study of 100 patients with severe refractory MG given ACTH.10 In four large retrospective studies of generalized MG using various doses of corticosteroids and with different follow-up durations, 74% of a total of 422 patients achieved AL 8697 good overall improvement of muscle strength or remission.11C14 A prospective study of 600 MG patients (151 generalized, 449 pure ocular) treated with moderate doses of corticosteroids followed by low-dose maintenance showed an overall improvement in 95% of cases, but no clear breakdown between the generalized and ocular cases were given.15 A randomized double-blind trial of prednisolone versus placebo in 13 patients with generalized MG showed no significant improvement of muscle strength at 6 months.16 Another.