Ritodrine-induced erythema multiforme.

Abstract

TO THE EDITOR: Ritodrine hydrochloride is a beta--sympathomimetic agent that significantly inhibits uterine contraction.' Some side effects of ritodrine (e.g., palpitations, tremor, nausea, vomiting) are relatively frequent;' neutropenia, metabolic disturbances, and pulmonary edema are less frequent.' We report the cases of two women who developed serious erythema multiforme during treatment. A 27-year-oldwoman, gravida I, para 0, in the 28th weekof twin pregnancy, was hospitalized because of premature contractions; the cervix was effaced 70 percent and closed. The presenting part (breech) of the first child was at station + I. The patient was given papaverine 80 mg im and dexamethasone 12mg im. Uterine contractions subsided considerably but did not disappear. At this point, ritodrine 100ltg/min iv was instituted. Five weeks after starting ritodrine therapy (33rd weekof gestation) the patient started complaining of pruritus on her abdomen, which spread to her chest and limbs. A fine maculopapular rash resemblingerythema multiforme was found on her whole body extending to the soles of her feet and palms (Figure I). There was no rash on the mucosal membranes. An extensive serological work-up was performed which proved negative for Epstein-Barr virus (EBV), cytomegalovirus (CMV), rubella, and coxsackie; Weil-Felix test, urinalysis, and cultures from skin and blood were negative. The white blood cell count (WBC) was normal, thrombocytes 170 OOO/mm', hemoglobin 10.5 g/dL, and hematocrit 31.3 g/IOOmt. Electrolytes, liver function tests, and clotting tests were normal. Ritodrine was stopped with gradual improvement of the pruritus and rash. The patient delivered twins four days later by cesarean section and the erythema disappeared after three days. Migration inhibiting factor assay (MIF) and mast cell degranulation test (MCDT) studied with ritodrine as an antigen were both negative. A 32-year-oldwoman, gravida I, para 0, was hospitalized because of premature contractions in the 27th weekof gestation. Ritodrine of 100ltg/min iv was instituted and the contractions subsided. After five weeks(32nd week of gestation) a maculopapular rash appeared on her body including her palms and the soles of her feet, accompanied by pruritus. The dermatological diagnosis was consistent with erythema multiforme (Figure 2). Urinalysis and cultures from skin and blood for bacteria and viruses were negative. Serological work-Up ruled out EBV,CMV, rubella, and coxsackie infection. The Weil-Felix test was negative. WBC, thrombocyte count, hemoglobin, hematocrit, electrolyte levels, liver function tests, and clotting tests were within normal range. MCDT