 |
 |
NMS, AWS August 1999 In its chapter on antipsychotic (neuroleptic) drugs, The Metck Manual briefly describes the rare but life-threatening condition Neuroleptic Malignant Syndrome (NMS), due to use of such drugs. About 1% of such users are at risk of NMS, and about 10% of the victims die. But NMS also may arise from use of drugs other than neuroleptics, specifically some common anti-PD drugs. Symptoms and signs are rather complex, but the main ones are high fever, muscular rigidity, and altered mental state. Curiously, Merck fails to mention an abrupt withdrawal syndrome (AWS, my neologism) just like NMS and due, not to intake but to suddenly reduced intake of certain drugs, again including some common anti-PD drugs. Examples below are from the maker-submitted and FDA-approved descriptive articles in the Physicians' Desk Reference (PDR): Amantadine(Symmetrel): Sporadic cases reported of NMS associated with dose reduction or withdrawal (Precautions). Benztropine(Cogentin): Severe anhidrosis (failure to sweat), fatal hyperthermia (fever), paralytic ileus (gut immobile), esp. if patient also on any of certain antipsychotics (Warnings). Carbidopa/Levodopa(Sinemet): Sporadic reports of syndrome like NMS (AWS), esp. if patient also using neuroleptics (Warnings). Clozapine(Clozaril): Several reports of NMS in patients using Clozaril alone or with other CNS-active agents (Warnings). Olanzapine(Zyprexa): No mention of this drug specifically, but general description of NMS included (Warnings). Pramipexole(Mirapex): One case of rhabdomyolysis (muscle death). Withdrawal-emergent hyperpyrexia and confusion: not from Mirapex specifically, but NMS-like syndrome associated with rapid dose reduction of antiparkinson drugs in general (Precautions}. Ropinirole(Requip): Though not reported with Requip, withdrawal-emergent hyperpyrexia and confusion associated with rapid dose reduction of antiparkinson drugs (Precautions). Selegiline(Eldepryl): Although Eldepryl at low dosage inhibits MAO-B selectively, it apparently is not always so. Severe CNS toxicity resulted in hyperpyrexia and death in one patient taking Eldepryl and the tricyclic antidepressant amitriptyline, and somewhat similar reaction has been associated with selective serotonin reuptake inhibitors (Warnings). Tolcapone(Tasmar): Hyperpyrexia and Confusion: In trials, four cases of a syndrome, like that reported on rapid reduction or withdrawal of other dopaminergic drugs, were associated with similar reduction of tolcapone. Rhabdomyolysis (muscle necrosis), possibly caused by the overexertion of prolonged rigidity, was also observed. One patient died, the others recovered slowly. Since marketing began, a few more cases reported (Precautions). Note: This is separate from tolcapone's liver-damage problem. Cheers, Joe -- J. R. Bruman (818) 789-3694 3527 Cody Road Sherman Oaks, CA 91403-5013