Potential contribution of prescription practices to the emergence and spread of chloroquine resistance in south-west Nigeria: caution in the use of artemisinin combination therapy.
BACKGROUND
Prescription practices have been shown to influence the emergence of anti-malarial drug resistance. Thus efforts in this study were devoted to evaluating the prescribing practices prior to introduction of the artemisinin based combination therapy (ACT) in Nigeria and its potential contribution to emergence of chloroquine resistant malaria in south-west Nigeria, in order to forestall a similar situation with the ACT.


METHODS
A retrospective quantitative study was designed to examine case records of patients treated for malaria in either a government or a private hospital in Ibadan, south-west Nigeria, over a 20-year period, cutting across three phases of resistance to chloroquine in Nigeria: pre-resistance, emerging resistance and dissemination of resistance. Patient prescriptions were examined for use of anti-malarial drugs, sub-therapeutic doses of chloroquine, co-administration of anti-histamines with chloroquine. Descriptive statistics of frequency and percentage were used to describe trends in the parameters assessed using EPI-info.


RESULTS
Case record files of 2,529 patients were examined. Chloroquine was the main drug used in treatment of malaria throughout the periods studied, with frequency of prescription at both sites ranging from 91.4% to 98.3% during the pre-resistance years. It was administered as standard doses during the pre resistance years. Anti-histamines, especially promethazine, were routinely co-administered with chloroquine at this period too. However, the practice of prescribing sub-therapeutic doses of chloroquine at the private health care facility coincided with the latter phase of emerging resistance and phase of dissemination of resistance. Frequency of prescription of sub-therapeutic doses increased from 6.7% in 1983 (pre-resistance years) to 43.6% in 1997 (dissemination of resistance phase) at the private health care facility. Frequency of co-administration of anti-histamines with chloroquine also reduced during the period of dissemination of resistance.


CONCLUSIONS
The results from this study describe a lack of adherence to national treatment guidelines, especially in the private sector, and a relationship between prescription practices and dissemination of drug resistant falciparum malaria. As Nigeria adopts the use of ACT, there is an urgent need to improve malaria treatment practices in Nigeria in order to prolong the clinical shelf-life of the combination.
Gbotosho
Grace O
GO
Malaria Research Laboratories, Institute of Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria. solagbotosho@yahoo.co.uk
Happi
Christian T
CT
Ganiyu
Abideen
A
Ogundahunsi
Olumide A
OA
Sowunmi
Akin
A
Oduola
Ayoade M
AM
D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use*; D037621:Artemisinins / Q000627:therapeutic use*; D002738:Chloroquine / Q000627:therapeutic use*; D004351:Drug Resistance; D004359:Drug Therapy, Combination / Q000592:standards; D006633:Histamine Antagonists / Q000627:therapeutic use; D006801:Humans; D016778:Malaria, Falciparum / Q000188:drug therapy; D009549:Nigeria; D010818:Practice Patterns, Physicians' / Q000592:standards*; D011398:Promethazine / Q000627:therapeutic use; D012189:Retrospective Studies
D000962:Antimalarials; D037621:Artemisinins; D006633:Histamine Antagonists; D002738:Chloroquine; D011398:Promethazine