AUGMENTATION OF THE RESTLESS LEGS SYNDROME WITH CARBIDOPA LEVODOPA/

Dopaminergic agents and carbidopa/levodopa have become the preferred t reatment for both the restless legs (RL) syndrome and for periodic lim b movements in sleep (PLMS). For once-nightly treatments with carbidop a/levodopa, a problem with morning end-of-dose rebound increases in le g movements has been reported to occur in the about one-fourth of the patients. In our clinical studies a previously unreported but far more significant problem of markedly augmented RL symptoms occurred in the afternoon and the evening prior to taking the next nightly dose. A sy stematic prospective evaluation of this augmentation in 46 consecutive patients treated with carbidopa/levodopa for RL syndrome or PLMS diso rder found this augmentation to be the major adverse effect of treatme nt. Augmentation occurred for 31% of PLMS patients and 82% of all RL p atients. It was greater for subjects with more severe RL symptoms and for patients on higher doses (greater than or equal to 50/200 mg carbi dopa/levodopa) but was unrelated to gender, age or baseline severity o f PLMS patients. This augmentation was severe enough to require medica tion change for 50% of the RL patients and 13% of PLMS patients. Augme ntation resolved with cessation of the medication and could be minimiz ed by keeping the dose low.