Efficacy of niprisan in the prophylactic management of patients with sickle cell disease

Background: Niprisan is a new drug extracted from indigenous herbs that has been developed by the Nigerian National Institute for Pharmaceutical Resea rch and Development for the prophylactic management of patients with sickle cell disease. Objective: The objective of this study was to assess the efficacy and toler ability of niprisan in the management of patients with sickle cell disease. Methods: This was a randomized, double-blind, placebo-controlled, crossover trial. Patients who met the criteria for homozygous sickle cell disease an d had 3 painful or vaso-occlusive crises per year were randomized to 1 of 2 study groups. Group A took niprisan 12 mg/kg body weight for 6 months befo re crossing over to placebo for another 6 months; group B took placebo for 6 months before crossing over to niprisan for another 6 months. There was a 1-month washout period before the crossover. The main outcome measures wer e the incidence of crises; the occurrence of painful episodes; certain clin ical, hematologic, and biochemical measures; and patients' daily self-asses sment of health. Results: Eighty-four patients met the inclusion criteria, but complete data were available for only 69 patients at the end of 12 months, 33 in group A and 36 in group B. Loss to follow-up was related to social and logistic fa ctors rather than study drug. One oral dose of 12 mg/kg niprisan daily sign ificantly reduced the frequency of sickle cell crises, bone pain, and hospi tal admission (P < 0.05). The mean number of crises per person per month wa s 0.05 in patients who received niprisan initially, compared with 0.11 per person per month after the crossover to placebo. Patients generally rated t heir health as better and reported less sickness and absenteeism with nipri san than with placebo. Apart from headache, which was reported by 9 patient s while taking niprisan, there were no important adverse effects. Conclusion: Niprisan was efficacious in the prophylactic management of pati ents with sickle cell disease, although additional confirmatory studies in larger sample sizes are needed.