Common adverse reactions include sedation, lethargy, vertigo, headache, nausea and diarrhea. Other infrequent side-effects are muscular hypotonia, urinary disturbances, confusion, speech disturbances, ataxia, hallucination, nightmares, euphoria, insomnia, depression, anxiety, agitation, tremor, nystagmus, paresthesias, seizures, myalgia, fever, respiratory or cardiovascular depression, hypotension, dry mouth, gastrointestinal disorder, sexual dysfunction, visual disorder, rash, pruritus, urticaria, hyperhidrosis, angioedema, rarely taste alterations, blood sugar changes and paradoxical increase in spasticity. Some of the CNS and genitourinary symptoms may be related to the underlying diseases rather than to drug therapy.