Correspondence

Failure of nifedipine treatment in primary pulmonary hypertension Sir, In an attempt to emulate the success described by Camerini et al. in a recent article in the British Heart Journal, ' we tried nifedipine in the treatment of a 36-year-old woman who had both clinical and haemo-dynamic findings of primary pulmonary hyper-tension. The patient was studied using a Swan-Ganz catheter; the procedure used by Camerini et al. was not changed. The following results were obtained: Only diazoxide at the lowest dose appeared to decrease total pulmonary resistance significantly. Nifedipine failed to do so. Other trials with mol-sidomine (a new long acting vasodilator) and hyd-ralazine were also unfruitful. As proposed by Klinke,2 drugs used to attempt to treat primary pulmonary hypertension need acute testing before being started on a long term basis; moreover, monitoring of the pulmonary vascular pressure is mandatory to avoid aggravating the condi-tion. We would like to emphasise that whereas prim-ary pulmonary hypertension may occasionally be ameliorated by various drugs, this response is indi-vidual and not the rule