Topical heparin for the treatment of acute superficial phlebitis secondary to indwelling intravenous catheterA double-blind, randomized, placebo-controlled trial

Objective: To assess the clinical efficacy of a topical gel containing 1000 IU · g⁻¹ of heparin, applied three times daily for a maximal period of 7 days to patients with acute superficial phlebitis secondary to indwelling intravenous catheter. Methods: A Double-blind, randomized, placebo-controlled study was conducted in one of the internal medicine wards of a tertiary General Hospital in Barcelona, Spain. Inpatients of both genders over 18 years of age that developed superficial phlebitis and gave informed consent were included in the study. The sample size estimation was 132 patients. Sixty-six patients were allocated to each group. There were five protocol deviations and 24 withdrawals in the intervention group, and one protocol deviation and 25 withdrawals in the control group. Consequently, 37 patients in the intervention group and 40 in the control group completed the trial. The main outcome measure was the disappearance of the symptoms and signs of superficial phlebitis. Clinical course, investigator's global impression and adverse events were also recorded. Results: According to the intention-to-treat analysis, after treatment for 7 days superficial phlebitis healed in 27 of the 61 patients (44.3%) who received topical heparin, and in 17 of the 65 patients (26.1%) receiving placebo, giving a relative risk [95% confidence interval (CI)] of 1.69 (1.03–2.78). This indicates that six patients (95% CI, 3–72) have to be treated in order to induce one additional healing. The clinical course and the overall clinical impression were similar in both groups. One patient treated with topical heparin developed mild urticaria. Conclusion: Topical heparin is safe and effective for the treatment of superficial phlebitis secondary to indwelling intravenous catheter. Received: 10 August 1998 / Accepted in revised form: 19 October 1998