Nefopam abuse

OBJECTIVE: To report 3 patients who abused nefopam, a central analgesic that inhibits serotonin, norepinephrine, and dopamine reuptake. CASE SUMMARIES: CASE 1: A 42-year-old white woman with migraines started nefopam therapy about 10 years ago. She now obtains nefopam by prescription forgery and self-administers intramuscular nefopam 300 mg/d. She experiences anticholinergic effects of nefopam and, when attempting withdrawal, depressive symptoms. CASE 2: A 40-year-old white woman with osteoporosis has injected 120 mg of nefopam intramuscularly daily for several years. When she tried to increase doses due to worsening of her symptoms, she experienced tremor, involuntary movements, and dry mouth, and became aggressive. She then resumed the initial doses. She now reports symptoms of depression when attempting withdrawal. CASE 3: A 33-year-old white man, with a history of alcohol and benzodiazepine dependence and ileostomy, and an implanted drug delivery system, has been prescribed nefopam. Fifteen days after therapy was initiated, his daily consumption was 840 mg/d, and further increased to 1840 mg/d. He experienced violent behavior, agitation, facial dysesthesia and myoclonus, tremor of fingers, and sweating. He did not attempt withdrawal. DISCUSSION: The patients described above are drug-dependent according to the Diagnostic and Statistical Manual, 4th Edition. All patients developed a pharmacodynamic tolerance phenomenon, which can develop rapidly. Violent behavior, tremor after massive intake, and depressive symptoms during withdrawal are similar to those reported with psychostimulant abuse. CONCLUSIONS: When abused, nefopam has primarily psychostimulant-like effects, which are probably linked to its dopamine reuptake inhibition properties.