“The intervals between reports of adverse reactions and drug withdrawal have not consistently closed over the past 60 years,” says lead author Igho Onakpoya, a medical researcher at the University of Oxford in the United Kingdom. “Of greatest concern, however, is the rate of withdrawal in Africa, which we found to be significantly lower than international counterparts.”
“The intervals between reports of adverse reactions and drug withdrawal have not consistently closed over the past 60 years.”
Igho Onakpoya, University of Oxford, United Kingdom
In the study, published last week (4 February) in the journal BMC Medicine, researchers analysed drug databases and the websites of regulatory authorities to identify products withdrawn from the market due to adverse reactions.
Between 1953 and 2013, they identified 462 products that were taken off the market, with an average interval of six years between the first reported reaction and withdrawal. Liver toxicity was the most common reason for withdrawal, followed by immune-related reactions.
During this period, “the rate of withdrawals per country was significantly lower in Africa” than on other continents, the paper says, with 1.17 drugs withdrawn per country in Africa, compared with 3.26 in Asia and 5.42 in South America.
The study estimated withdrawals per country and per million people, but did not compare withdrawal rates to the overall pool of licensed drugs in each country.
According to Onakpoya, low withdrawal rates in Africa may be attributed to ineffective or non-existent regulatory bodies, and a focus on granting marketing licences for imported products rather than monitoring the safety of drugs once they are on the market.
Another reason is that health professionals and patients in Africa report fewer adverse reactions than those on other continents in the first place, he adds.
Among other measures, the authors call for universal guidelines to be drawn up on withdrawing drugs, better access to clinical trial reports and stronger drug monitoring in developing countries, especially in Africa.
Margareth Ndomondo-Sigonda, who coordinates the African Medicines Regulatory Harmonization Programme, says the challenges are “so enormous” that African countries realise they must share information and efforts.
The programme is an African Union initiative that helps countries develop policies that harmonise drug regulations.
Citing the African Medicines Regulators Conference, held in Ethiopia in December 2015, as well as renewed calls from the World Health Organization and the African Union to establish an African Medicines Agency, Ndomondo-Sigonda says the outlook is good.
“The urgency for drug regulation is growing, and with people now working together in a unified way, we hope to see robust regulatory systems across the continent,” she says.