Riamet: Dosing and Timing

Availability	Tab Riamet ( Arthemether 20mg/ Lumefantrine 120mg)
Indication	Treatment of acute uncomplicated malaria infections caused by a parasite called “Plasmodium falciparum”.
Dosing	Weight Num of tabs Num of tabs in total course 10-15kg 1 tab 4 tabs 15-25kg 2 tabs 8 tabs 25-35kg 3 tabs 12 tabs >35kg 4 tabs 16 tabs
Timing	1.       Six doses are taken over 3 days. 2.       One tablet at the time of onset of symptom, again after 8 hours and then twice daily on each of the following two days (8, 24, 36, 48 and 60 hours after the first dose) 3.       All doses must be taken and at the right times, to gain the full benefits of this medicine.
Missed Dose Management	Take the missed dose as soon as you remember unless it is almost time for your next dose.  Then take your next dose at the usual time.  Do not take a double dose to make up for a forgotten dose.If vomits within 1 hour of taking the tablets, take another dose.
Wrong Administration Time Management	Not mentioned in product leaflet. No published literature on the management Based on study by Ehrhardt & Meyer, 2009, Pharmacokinetic– pharmacodynamic (PK–PD) data, suggested that the main PK determinant of cure was either the area under the actual plasma lumefantrine concentration time curve (AUC) or, as a proxy, the concentration of lumefantrine at day 7.  Lumefantrine plasma concentrations at day 7 of >500 ng/mL are required to result in cure rares of more than 90%.  To increase the AUC, a 6-dose regimen was then tested and proved highly effective and well tolerated in adults when each 4 tablets were given at 0, 8, 24, 36, 48 and 60 hours of the treatment course. Conclusion: Treatment success is dependent on plasma concentration.

References:  

1. Riamet product leaflet
2. NAG, 2014
3. Ehrhardt, S., & Meyer, C. G. (2009). Artemether-lumefantrine in the treatment of uncomplicated Plasmodium falciparum malaria. Therapeutics and Clinical Risk Management, 5, 805–15. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/19851528