A double blind, randomised, multicentre comparison of two doses of intravenous iloprost in the treatment of Raynaud's phenomenon secondary to connective tissue diseases.

OBJECTIVE: To compare low (0.5 ng/kg/min) and standard dose (2 ng/kg/min) iloprost (a stable carbacyclin analogue of prostacyclin) in patients with Raynaud's phenomenon secondary to connective tissue disorders.

DESIGN: Double blind, random allocation, three six hour infusions on consecutive days. Follow up period eight weeks.

SETTING: Rheumatology units, five teaching hospitals.

PATIENTS: 55 Patients with Raynaud's phenomenon (greater than seven attacks per week), 32 secondary to well documented classical progressive systemic sclerosis (American Rheumatism Association criteria), 11 CREST syndrome, 5 mixed connective tissue disease, 1 rheumatoid arthritis, 1 Sjögren's syndrome, 1 childhood dermatomyositis, and 4 abnormal nailfold capillaroscopy and antibody profiles but no definite diagnosis.

INTERVENTIONS: All other treatment for Raynaud's phenomenon was discontinued two weeks before entry. 28 Patients were randomly allocated to receive the low dose, 27 the standard dose. Differing dilutions allowed infusion rates to be started at 10 ml/h with increments of 10 ml/h every 15 minutes until infusion rates reached 0.5 ng/kg/min and 2 ng/kg/min respectively. MAIN OUTCOME MEASURE(s)--Reduction in frequency, duration, and severity of attacks of Raynaud's phenomenon. Assessment of ulcer and ischaemic lesion healing.

RESULTS: Both dosage regimens were equally effective in reducing severity, frequency, and duration of Raynaud's attacks. Ulcer healing occurred to similar degree in both treatment groups (standard dose 44%, low dose 39%). Low dose was associated with significantly fewer side effects.

CONCLUSIONS: Both dosage regimens reduce severity of Raynaud's phenomenon and encourage ulcer healing. Low dose was associated with fewer side effects and was better tolerated by the patients.