SHOULD THALIDOMIDE BE INCLUDED IN THE PHILIPPINE NATIONAL FORMULARY FOR THE TREATMENT OF ERYTHEMA NODOSUM LEPROSUM?

Leprosy remains to be an important public health problem in the Philippines. Despite the WHO recommendation of oral prednisone and clofazimine for the treatment of erythema nodosum leprosum (ENL), this view is not shared by all experts worldwide, and many have questioned the evidence behind this claim (Naafs 2006).

Purpose: This paper aims to analyze the need to reconsider thalidomide for inclusion in the Philippine National Formulary (PNF).

Method: Thalidomide was assessed based on the following criteria for inclusion in the core list: 1)burden of the illness, 2) efficacy and safety, 3) pharmacoeconomics, 3) appropriateness to the capability of health workers at different levels of health care.

Result: Although the prevalence rate of leprosy is <1%, the Leprosy Control Program is still identified as one of the key health programs of the Department of Health (DOH). Since treatment of lepra reactions is a priority strategy for further reducing the leprosy burden (WHO 2011), thalidomide may then be considered as an important drug for the Leprosy Control Program. Thalidomide fulfils the efficacy criteria of PNF with a relative risk for thalidomide based on the outcome for preventing future ENL relapses of 0.18 (CI 0.071, 0.464) and NNT 1.66. The main concern regarding thalidomide use is its teratogenicity. There are still reports of thalidomide embryopathy (TE). Thirty-four cases of TE were reported between 1969-1996 in South America, and 2 suspected cases were identified between 2007-2008. Another disadvantage of thalidomide is the cost (Php76,881 per patient; cost-effectiveness ratio of Php163,576.60 per ENL case prevented), compared to Prednisone (Php651 per patient; cost-effectiveness ratio of Php3,829.41) and Clofazimine, which is free. Leprosy patients experiencing ENL require expert care. And since thalidomide may have serious side effects, it should only be used in specialty treatment centers.

Conclusion: After a thorough evaluation of thalidomide against the various criteria, thalidomide does not fulfil the criteria for inclusion in the core list of essential medicines in the PNF because of questions on its safety and cost-effectiveness. However, assuming strict regulations can be enforced to prevent birth defects; thalidomide may be recommended in the PNF complementary list as alternative treatment for patients unresponsive to oral steroids or clofazimine, or those seeking for other treatment options due to the untoward effects of the other treatment modalities.