Neuromuscular effects of monoamine oxidase inhibitors

The MAOI drugs produce neuromuscular effects at therapeutic and toxic doses when given alone or in combination with other drugs. These effects range from muscle tension and twitches to forceful myoclonic jerks. These effects may also be a part of a more pervasive toxic syndrome that includes autonomic and mental symptoms as well. There is some evidence that serotonergic mechanisms play a role in mediating the neuromuscular effects of MAOIs. The authors have hypothesized that MAOIs produce a condition of heightened neuromuscular excitability due to a combination of increased serotonergic tone and central disinhibition of alpha-motoneuron mediated spinal activity. Further study is needed in which objective pharmacologic and neurophysiologic measures are used.