Some travelers, who may think they will save money, wait to buy expensive anti-malVerdana drugs and other medications in foreign countries. Recent studies reported in Tropical Medicine and International Health and World Health Organization (WHO) publications have shown that many foreign-bought medications are substandard. Sophisticated chemical analysis of 96 samples of chloroquine and selected antibacterials that were bought in pharmacies and non-pharmacies in Nigeria and Thailand, showed that 36.5% of these preparations were substandard.

In most developing countries, items that require a prescription in the Western world are readily available over-the-counter or are sold in non-pharmacies. Commonly used drugs chosen by researchers for testing included chloroquine, amoxicillin, tetracycline, trimethoprim/sulfamethoxizole, ampicillin and cloxicillin. Although there could be many reasons for poor quality – including fraud, poor manufacturing techniques or decomposition due to poor storage – the study concluded that the major reason for inferior medications were likely poor manufacturing procedures and inadequate quality assurance. These were compounded by the decomposition of active ingredients, probably the result of storage under adverse climatic conditions such as high humidity and high temperature. There were six cases in which medications – 5 chloroquine products and one amoxicillin product – contained no active ingredient. All of the samples tested were within their expiration dates. Treatment failure and drug resistance are possible consequences of the use of substandard drugs.