fixed drug eruption induced by meprobamate and confirmed by positive patch test

A ZAIEM, W KAABI, R SAHNOUN, R DAGHFOUS, M LAKHAL, S EL AIDLI. Centre National de Pharmacovigilance, Recueil et Analyse des effets indésirables, Tunisia

Introduction:

Meprobamate is a drug widely prescribed in Tunisia for anxiety disorders or for the short-term relief of the symptoms of anxiety. Drowsiness is the most frequent adverse effect of meprobamate. Other effects include nausea, vomiting, diarrhoea, paraesthesia, weakness, and CNS effects. Fixed drug eruption (FDE) is an exceptional cutaneous adverse effect of this drug. We report a case of FDE induced by meprobamate with positive patch test.

Case report:

HZ, a 22-year-old woman, was prescribed for depression Mepronizine® (meprobamate and aceprometazine), Depamide® (valpromide) and Temesta® (lorazepam). On the second day of treatment, the patient presented red erythematous and pruriginous plaques in her right forearm (2 plaques), in her left hip (3 plaques), in her neck (1 plaque) and in her thighs (2 plaques). After stopping the previous treatment, the patient\'s lesions resolved completely within 3 weeks with residual pigmentation.

One month later, we performed patch tests with Mepronizine®, meprobamate alone, Depamide® and Temesta® at concentrations of 10% in petrolatum. These patches were placed on the residual pigmented lesions. Twenty four hours later, the patient presented reactivation of lesions on which were placed Mepronizine® and meprobamate patches. Depamide® and Temesta® were reintroduced later without reactivation of the previous lesions of FDE.

The case was notified to the pharmacovigilance center and was analysed according to Begaud’s method of imputation.

Discussion:

The intrinsic imputation score of Mepronizine® was valued as I3 (likely relationship) because of the suggestive delay of occurrence of FDE, the regression of erythema after drug withdrawal and the suggestive semiology (FDE is exclusively induced by drugs). The intrinsic score of Depamide® and Temesta® was valued as doubtful because of the negative rechallenge.

The role of meprobamate in the genesis of this FDE was retained mainly because of the positive patch test prepared with meprobamate alone.

FDE to meprobamate is an exceptional adverse effect of this drug which was reported only in few cases.

Conclusion:

This study reported an exceptional case of FDE induced by meprobamate, which was confirmed by positive patch test.