Limited evidence shows that medicines derived from plants (so-called phytomedicines) may help reduce painful crises in sickle cell disease, according to a Cochrane review of 2 trials involving 282 participants. Among the findings:

• Niprisan may help to reduce episodes of sickle cell disease crises associated with severe pain, though further trials are required to fully assess its role.
• Ciklavit requires further study before recommendations can be made regarding its use.
• No serious adverse symptoms or derangement of liver or kidney function was reported with either formulation.