Epidemiological study of cutaneous adverse drug reactions in oman

Cutaneous adverse drug reactions (CADR) from all regions of Oman are monitored by spontaneous adverse reaction reporting and monitoring system.

A total of 100 patients with cutaneous adverse drug reactions were analyzed in a cohort study for 15 months from 1(st) June 2005 to 31(st) August 2006.

Out of 100, 85 cases were reported in one year time; from 1(st) of June 2005 to 31(st) of May 2006, where 80 were Omani patients and 5 expatriates. Therefore, the incidence was found to be 36 cases per million of total population of Oman (85/ 2,340,815), and 45 per million of Omani population (80/ 1,781,558) for that period. CADR patients comprised 8.5% of the total admitted patients in the skin ward at Al-Nahda Hospital; a tertiary dermatology center. While incidence of CADR among outpatients attending dermatology clinics in Al-Nahda hospital was found to be only 0.3%. Under reporting was the main reason behind this low incidence. However, relatively higher incidence was reported in cases of Toxic Epidermolytic Necrosis (TEN); 2 per million. The clinical patterns and the drugs causing CADR are remarkably similar to those observed in other countries except for minor variations. Urticaria followed by Fixed Drug Eruptions (FDE) and Maculopapular Eruptions (MPE) were the most common reactions. Based on WHO definition of severe ADR; 21% of the cases were classified as severe reactions. One death reported a case of TEN due to Intramuscular Diclofenac. Non-steroidal,anti-inflammatory drugs (NSAIDs) and the antimicrobial agents were the most frequent offending drugs. Most cases of TEN were caused by injection Diclofenac, where most of FDE were caused by NSAIDs.

Based on these results; it was recommended in a circular no. 44/2007/47 from the Director General of the Directorate of Drug Control to restrict the use of Diclofenac Injection.