Did antismoking therapy make him sick?
Mr. M has symptoms of neuroleptic malignant syndrome. For years, he has been taking antipsychotics without suffering complications. What caused his acute episode?
Other possibilities. Mr. M’s pneumonia might have caused dehydration, which can also lead to NMS.
Bupropion also reportedly alters metabolism of chlorpromazine and other phenothiazine antipsychotics by inhibiting the cytochrome P-450 2D6 isoenzyme. This pharmacokinetic interaction could have precipitated Mr. M’s NMS episode independent of an antipsychotic dosage increase.16
Because this case is so complex, pinpointing a specific cause for Mr. M’s apparent NMS symptoms is difficult. Be aware that combining psychotropics can lead to NMS. Patients who present with mental status changes, hyperthermia, rigidity, and/or increased creatine kinase while taking psychotropics should be promptly evaluated and managed.
Treating NMS
A review of NMS treatment by Davis et al17 suggests that you:
- consider NMS in the differential diagnosis of an acutely delirious patient who has used antipsychotics, no matter how long he or she has been taking the medication(s) or how stable the dosage
- check for other signs of NMS—such as rigidity or autonomic instability—during the physical examination.
- consider NMS as a possible cause of dysarthria, diaphoresis, dysphagia, sialorrhea, and myoclonus, although these are less common signs of the disorder
- include CPK levels, chemistry panel, CBC, and liver enzyme assessment in the early evaluation of laboratory results. Consider performing a urine drug screen to check for illicit substance use. Head CT results might also help confirm NMS diagnosis.
If sedation becomes necessary, use benzodiazepines cautiously. Serial CPKs and daily reassessment of clinical degree of rigidity are essential; continued rigidity may indicate use of dopamine agonists and dantrolene.17
Related resources
- Neuroleptic Malignant Syndrome Information Service. Archive of articles addressing NMS diagnosis and treatment, and listing of psychotropics associated with NMS. www.nmsis.org.
- Aripiprazole • Abilify
- Benztropine • Cogentin
- Bupropion SR • Wellbutrin, Zyban
- Ceftazidime • various
- Chlorpromazine • Thorazine
- Dantrolene • Dantrium
- Donepezil • Aricept
- Lithium carbonate • various
- Lorazepam • Ativan
- Olanzapine • Zyprexa
- Risperidone • Risperdal
The authors report no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.
