Global warming and performance of antiepileptic therapeutics

During early 1990s, there were 30 million patients with epilepsy in the world1. They require long-term medication with various antiepiletic formulations. The efficacy of various therapeutic formulations being offered to those suffering from an epileptic disorder (Table 1) could be severely lowered in the face of impending global warming and frequent occurrence of the El niño effects. Even though the recommended storage temperatures for various antiepileptics (Table 1) range between 15–25 ◦C or 15–30 ◦C2, and none requires refrigeration facilities, an inadvertent exposure to higher temperatures could vitiate their therapeutic efficacy. A new record concerning global temperatures was established during July 1998, when the average global temperature reached 15.5 ◦C, and July 1998 was recorded as the hottest month in nearly 120 years3. Moreover, high ambient temperatures when accompanied by high humidity would involve enormous transmission of heat to antiepileptics. This was evident during the 1995 heatwave in Chicago when the maximum temperature recorded was 40 ◦C, though the heatindex, the estimate of radiative and evaporative transfer of heat, was 48.3 ◦C4. The high heat-index in developing countries when accompanied by poor electricity supplies would upset electrically-operated cooling facilities5. The cumulative effect of high ambient temperatures, heat-index and poor air-cooling would be disastrous on potency and bioavailability of various antiepileptics. The antiepileptic formulations (Table 1) with desired storage temperature maxima of 25 or 30 ◦C2, would not be expected to behave differently from therapeutic agents with identical storage requirements during field usage. This is vindicated from the field efficacy of ampicillin, sulfamethoxazole and trimethoprim, storage temperature not exceeding 25 ◦C2, and acetaminophen and vitamin B2 preparations, storage temperature not exceeding 30 ◦C2, in Bangladesh during the early 1990s. An analysis of 137 brands of the above four therapeutics, being marketed in various regions of Bangladesh, for residual potency, revealed that there were 37 sub-standard formulations being offered