The quality of antihypertensive drugs sold in Lagos State depicts the prevalence of falsely labelled and substandard nifedipine tablets, the most commonly used drug to treat hypertension is high, experts have said.
In a recent study, researchers tested the quality of nifedipine tablets collected from registered pharmacies in Lagos State and found 76.5 per cent of them were of poor quality, Trubune reports.
In this first study of antihypertensive drugs in Lagos State, the researchers collected 14 brands of nifedipine tablets from 17 pharmacies in each of the six local government areas (LGAs).
The 2019 study in the journal PLoS ONE was entitled “Evaluating the quality of antihypertensive drugs in Lagos State, Nigeria”.
It involved Elizabeth Thithi Ndichu; Kelechi Ohiri; Oluwafemi Sekoni; Olasunmbo Makinde and Kevin Schulman.
Of the 102 branded nifedipine tablets collected between May and July 2017, 30 (29.3 percent) were falsely labeled, 76 (74.5 percent) were substandard, 78 (76.5 percent) were of poor quality and 24 (23.5 percent) were of good quality.
Among the false nifedipine tablets, two samples met the standards set for purity while 28 did not. Among the 76 substandard nifedipine tablets, 28 were also falsely labeled.
Overall, of the 30 (29.4 percent) falsely labeled nifedipine tablets, 18 (60 percent) were from manufacturers in Asia, seven (23.3 percent) from Africa and came from manufacturers based in Nigeria, and five (16.7 percent) from Europe or unknown locations.
Of the false nifedipine tablets, 17 (56.7 percent) came from LGAs with low socioeconomic status, and 40 (52.6 percent) of the substandard drug samples came from LGAs with high socioeconomic status.
Most of the good-quality nifedipine tablets, 14 (58.3 percent), were from LGAs with low socioeconomic status. Eighteen (60 percent) of the falsely labeled nifedipine tablets, 37 (48.7 percent) of the substandard nifedipine tablets, and 15 (62.5 percent) of the good-quality nevirapine tablets were from manufacturers based in Asia.
This study revealed that the challenges of assuring drug quality at the retail level where drug quality is impossible to determine from visual inspection alone given that the packaging of both poor- and high-quality drug were similar.
Given the study’s findings that the price of nifedipine tablets was not related to quality, they suggested that it is possible for manufacturers to supply high-quality products to this market at current market prices.
According to them, “Treatment of noncommunicable diseases in this setting will require efforts to monitor and assure drug quality.”
Addressing the prevalence of low-quality drugs, they declared, can use strategies based on a public regulatory approach, a private market approach, or a combination of the two.