Reactions 758 - 3 Jul 1999

SClomipramine

Serotonin syndrome: case reportA 60-year-old woman developed serotonin syndrome

during treatment with clomipramine for depression andanxiety.

The patient had taken clomipramine 200 mg/day for 5months, with a serum concentration of 1600 nmol/L (normal< 1900). Her clomipramine dosage was then increased to 250mg/day, but another serum concentration was not obtained.Three months after this dosage increase, the woman presentedwith confusion, weakness, anxiety, profuse diarrhoea andtremulousness, and she was uncoordinated. Her BP was100/50mm Hg, she had a fever of 41.6°C, facial twitching,sustained bilateral clonus at the ankles and myoclonic jerkingof her left leg.

Laboratory tests showed the following serum levels: calcium1.81 nmol/L (normal 2.2–2.58), magnesium 0.66 nmol/L(0.8–1.2), creatine phosphokinase 4300 U/L (< 150),increasing to 39 900 U/L within 72 hours; AST 3560 U/L (< 35)and ALT 2680 U/L (<35). Her platelet count decreased from269 000/mm3 on admission to 44 000/mm3 in 24 hours andcoagulation studies were consistent with disseminatedintravascular coagulation. An ECG showed ventriculartachycardia and an electroencephalogram showed generalisedslowing with epileptiform activity. Her serum clomipramineconcentration was 1100 nmol/L and that of the majormetabolite was 1130 nmol/L, giving a total of 2230 nmol/L(normal < 1900).

A few hours after the patient was hospitalised, she becameobtunded and was transferred to an intensive care unit. Shewas treated with cooling blankets, IV fluids, lidocaine,phenytoin and broad-spectrum antibacterials. However, herhypotension and ventricular tachycardia were difficult tocontrol. Rhabdomyolysis resulted in acute renal failure and sherequired dialysis. Four weeks after she was hospitalised, thepatient developed opportunistic infections and died.Rosebush PI, et al. Serotonin syndrome as a result of clomipramine monotherapy.Journal of Clinical Psychopharmacology 19: 285-287, Jun 1999 -Canada 800767556

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Reactions 3 Jul 1999 No. 7580114-9954/10/0758-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved