Do national medicinal drug policies and essential drug programs improve drug use?: a review of experiences in developing countries.

Increasing concerns regarding access to and appropriateness of medicinal drug use have led many governments in developing countries to develop national policies and regulations intended to increase the affordability, supply, safety, and rational use of pharmaceuticals. However, little is known about the intended and unintended impacts of these social experiments on actual drug use. We conducted a critical review and synthesis of the international literature in an attempt to define the current state of knowledge regarding drug policy effects on drug use, and to extract from the evidence important lessons for future policy and research. Literature sources included the archives and computerized databases, articles published in medical and pharmacy journals, as well as published annotated bibliographies. The evaluated interventions included three broad categories: (1) multi-component national drug policies including essential drug programs; (2) drug supply and cost-sharing programs; and (3) regulatory measures. Most of these studies utilized weak research designs that evaluated programs solely on the basis of post-intervention measures. Only two studies measured pre-policy utilization, but did not include a control group. Thus, none of the results are conclusive, and the findings represent, at best, hypotheses for more rigorous studies of policy impacts. Some suggestive findings include an association between increases in the supply of essential drugs (combined with training) and more appropriate use of medications in primary care settings. In addition, preliminary data suggest some unintended effects of de-registration of drugs or upward reclassification of specific medicines. Similarly, loosening restrictions have sometimes been accompanied by increased dispensing of specific drugs by unqualified personnel. The available studies focused only on a few categories of national and regulatory policies. Because of poor study design, the results do not provide valid data to determine whether national drug policies improve drug use. Moreover, no studies have evaluated the effects of major and recent changes, such as increased use of product patents, national pharmaceutical insurance policies, and increased privatization of pharmaceutical products and services. Future studies need to explore the consequences of these emerging developments on drug access and use. Despite the difficulties inherent in evaluation of national policies, stronger research designs can and should be carried out. Interrupted time-series analysis and other more rigorous designs should become standard designs for policy evaluation in the same way that standard treatment guidelines are intended to guide medical practice.

Efficacy and safety of liposomal amphotericin B (AmBisome) for visceral leishmaniasis in endemic developing countries.

Reported are the results of a study to determine the efficacy and safety of liposomal amphotericin B (AmBisome) for treating visceral leishmaniasis (kala-azar) in several developing countries where the disease is endemic (Brazil, India, and Kenya). At each study site, sequential cohorts of 10 patients each were treated with AmBisome at a dose of 2 mg.kg-1.day-1 (2 MKD). The first cohort received regimen 1:2 MKD on days 1-6 and day 10 (total dose: 14 mg/kg). If the efficacy with this regimen was satisfactory, a second cohort received regimen 2:2 MKD on days 1-4 and 10 (total dose: 10 mg/kg); and a third cohort received regimen 3:2 MKD on days 1, 5, and 10 (total dose: 6 mg/kg). In India, regimens 1, 2, and 3 (which were studied concurrently) each cured 100% of 10 patients. In Kenya, regimen 1 cured all 10 patients, regimen 2 cured 90% of 10 patients, but regimen 3 cured only 20% of 5 patients. In Brazil, regimen 1 was only partially curative: 5 of 13 patients (62%). Therefore, 15 patients were administered regimen 4 (2 MKD for 10 consecutive days; total dose, 20 mg/kg) and 13 patients were cured (83%). These results suggest that for the treatment of kala-azar the following doses of AmBisome should be administered: in India and Kenya, 2 mg/kg on days 1-4 and day 10; and in Brazil, 2 mg/kg on days 1-10.

PIP: The efficacy and safety of liposomal amphotericin B (AmBisome) for the treatment of visceral leishmaniasis (kala-azar) were evaluated in a phase II clinical trial conducted in Brazil, India, and Kenya--countries where kala-azar is endemic. At each study site, sequential cohorts of 10 patients each received three different dosage regimens of AmBisome. The first cohort received 2 mg/kg/day (MKD) on days 1-6 and day 10 (total dose, 14 mg/kg). If the efficacy of this regimen was satisfactory, the second cohort received 2 MKD on days 1-4 and day 10 (total dose, 10 mg/kg) and a third cohort was administered 2 MKD on days 1, 5, and 10 (total dose, 6 mg/kg). In India, all three regimens (studied concurrently) cured 100% of the total of 30 patients. In Kenya, the first regimen cured all 10 patients (100%), the second cured 9 of 10 patients (90%), and the third cured only 1 of 5 patients (20%). In Brazil, since the first regimen cured only 5 of 13 patients (62%), the next 15 patients were given 2 MKD for 10 consecutive days (total dose, 20 mg/kg); this intensified regimen cured 13 of the 15 patients (83%). Adverse effects were minor, primarily fever and chills associated with infusion and irregular pulse. These findings suggest that leishmaniasis patients in India and Kenya should receive 2 mg/kg of AmBisome on days 1-4 and day 10, while those in Brazil should be given 2 mg/kg on days 1-10. AmBisome treatment is especially recommended for those for whom standard agents are likely to be ineffective, toxic, or difficult to administer.

Globalisation of drug regulation and drug regulators in developing countriesGroping in the dark even when there is a light switch; an example from Sri Lanka.

Drug regulatory agencies in developing countries are often relatively small and poorly funded; they are therefore necessarily heavily dependent upon the experience gained and the assessments carried out by larger national agencies elsewhere. This applies both to the basic efficacy/safety evaluation of new chemical entities and the quality evaluation of products based on well-known active components and also to other acts of major agencies, e.g., with respect to unexpected problems arising with a drug or the correction of inadmissible advertising. To date, far too little information on these matters is available to the agencies of developing countries. In part this is due to lack of formalised international arrangements, but the agencies which should be able to provide this information are also sometimes poorly structured to do so, and in some instances serious doubts exist as to the reliability of regulatory work carried out elsewhere, whether this relates to evaluation of drugs, inspection of manufacturing plants or other matters. These problems are often compounded by the fact that agencies in developing countries may have an insufficient legal infrastructure to carry out their task to the full.

Debrisoquine and mephenytoin oxidation in Sinhalese: a population study.

The frequency distributions of the 0-8 h urinary metabolic ratios of debrisoquine and mephenytoin were measured in 111 healthy, unrelated Sinhalese resident in Sri Lanka. Blood samples were taken from 77 of these subjects for CYP2D6 genotyping. Bimodality in the distribution of the log10 debrisoquine/4-hydroxydebrisoquine ratio was not evident from visual inspection and by kernel density analysis. The results of genotyping indicated that 82% of the population were either homozygous for the wild-type CYP2D6 gene or heterozygous for the wild type allele and the whole gene deletion. Eighteen per cent of the Sinhalese population were heterozygous for the CYP2D6B mutation and the wild-type allele. All of these genotypes give rise to the extensive metaboliser phenotype in white Caucasians. No CYP2D6A mutations were identified and no individuals who were homozygous for the mutant alleles were detected, which is in accord with an absence of phenotypic poor metabolisers of debrisoquine. The mutant CYP2D6 allele frequency in Sinhalese (9%) is only half that observed in white Caucasians. The S/R-mephenytoin ratio ranged from 0.09 to 2.27 (median 0.38). By visual inspection and kernel density analysis the distribution of the S/R-mephenytoin ratio was bimodal and, using a value of 0.9 for the antimode, 16 (14%) subjects were poor metabolisers. In conclusion, the prevalence of the poor metaboliser phenotype in Sinhalese appears much lower for debrisoquine and higher for mephenytoin than in white Caucasians. These findings are similar to those observed in Indians living in Bombay and in Oriental populations.

Essential drugs and registration of pharmaceuticals: the Sri Lankan experience.

Many factors influence the regulation of pharmaceuticals in a country. The essential drugs concept, formulated by the World Health Organization to assist developing countries in selecting appropriate drugs, also provides a basis for regulation. Sri Lanka has long regulated pharmaceuticals as part of its health policy. Over 70% of 3436 pharmaceutical product registrations were found to be drugs (or alternatives) named in the country's essential drugs list. This is despite the fact that product registrations are mainly for the private health care sector, and the list is for the state sector. The essential drugs concept therefore appears to have influenced the pharmaceuticals registered in Sri Lanka.