Whether through formal or informal channels, many people in Africa get their malaria drugs from the commercial sector comprised of private clinics, retail pharmacies, the ubiquitous drug shops or even hawkers in the market. A few years ago, The Lancet reported that drug quality is often compromised simply by the conditions under which these medicines are kept. Now a study in PLoS One revisits the quality issue from two points of view – the actual content of the tablets and the appropriateness of medicines in stock.
The Lancet article (Taylor et al., 2001) reported that in Nigeria shops, “279 (48%) samples did not comply with set pharmacopoeial limits, and this proportion was uniform for the various types of drugs tested. Although some preparations contained no active ingredient, most had amounts just outside the pharmacopoeial limits. We identified samples with both too much and too little active drug content.”
The new study by Bate and colleagues tested “195 different packs of malaria drugs sold in six African cities (and) showed 35 per cent of them either did not contain high enough levels of active ingredient or did not dissolve properly.” World News Australia quoted Dr Bate who explained that, “”Our study shows that efforts to increase access to quality antimalarial drugs in Africa are increasingly important. Substandard drugs not only endanger lives today, but also jeopardise future malaria treatment strategies by accelerating parasite resistance.”
Concerning the specific medicines located and tested, Bate and colleagues found that, “38% of SP, 48% of amodiaquine, 24% of mefloquine, 31% of artesunate, 27% of artemether, 55% of dihydroartemisinin and 19% of artemether- lumefantrine fixed-dose combinations” failed testing by thin-layer chromatography (TLC), dissolution or both.
The actual availability for sale of certain drugs was also cause for concern. WHO has actively recommended against use of monotherapy artemisinin-based drugs to avoid the dangers of promoting resistance to this lifeline of malaria treatment. Specifically, WHO observes that 10 endemic countries never registered monotherapies, 13 have taken regulatory measures against artemisinin montherapy, while another 13 have stated their intentions to do so. Nigeria, one of the largest markets for malaria drugs, is not on this list.
Nigeria appears to be taking a passive approach to artemisinin monotherapies – letting the registration of those already approved lapse. Visits to medicine shops from Abuja to Uyo confirm that this policy does not result in the quick removal of the medicines. Since artemisinin drugs have a shelf life of less than two years, another passive approach would have been to simply disallow further import and let existing stocks run out, but the approach based on lapsing registration allows continued imports.
Another concern about the drugs found in Bate’s study and in visits to Nigerian shops is the continued presence of sulfadoxine- pyrimethamine (SP) for sale as a treatment drug. Since SP is currently the only drug approved for IPTp and since SP continues to experience growing resistance in children, the wise decision in theory has been to withdraw SP from the market and from treatment generally and reserve it only for IPTp in antenatal care clinics.
Promulgations and policies either by global organizations or national bodies do little to help control malaria if there is no functional regulatory enforcement in place. We will quickly lose more malaria control tools – pushing the hope for eradication even farther into the future.