Drug-induced exanthem following dabigatran.

OBJECTIVE

To report an incident of a drug-induced exanthem during treatment with dabigatran in a patient without prior exposure to the drug.

CASE SUMMARY

A 20-year-old white male was prescribed oral dabigatran 150 mg twice daily for thromboembolic prevention because of nonvalvular atrial fibrillation. After 2 weeks of dabigatran therapy, a raised, pruritic, erythematous rash developed on the patient's inner thigh and forearm. Upon discontinuation of dabigatran and initiation of oral corticosteroid treatment, the rash resolved. Dabigatran therapy was not readministered and thromboembolic prevention therapy with warfarin was instituted.

DISCUSSION

The clinical evidence for efficacy of dabigatran was derived largely from the RE-LY trial, which provided an open-label comparison with warfarin for the reduction of stroke and systemic embolism in nonvalvular atrial fibrillation. The most frequent adverse reactions leading to discontinuation of dabigatran were bleeding and gastrointestinal events. In the RE-LY study, drug hyper-sensitivity, allergic edema, anaphylactic reaction, and anaphylactic shock were reported in <0.1% of patients receiving dabigatran. Despite the low incidence of hypersensitivity reported in the RE-LY trial, the use of the Naranjo probability scale indicated a probable relationship between the rash and dabigatran therapy in this patient.

CONCLUSIONS

Upon initiation of dabigatran therapy, surveillance for hyper-sensitivity reactions should be included as part of routine drug monitoring.