Modification of Piroxicam-Mediated Analgesia in Lamivudine-Artesunate Treated Mice

Temidayo Olurishe1, Helen Kwanashie1, Joseph Anuka1, Haruna Muktar2. 1Department of Pharmacology and Clinical Pharmacy, Ahmadu Bello University, Zaria, Kaduna, Nigeria, 2Haematology Department, Ahmadu Bello University Teaching Hospital, Zaria, Kaduna, Nigeria.

Pain is often associated with HIV-malaria co-morbidity. With lamivudine (3TC) and artesunate (AS) being components of drug management in the co-morbid state, pharmacological response to analgesics may be altered. This study investigated possible effects of 3TC-AS administration on piroxicam (PM) mediated analgesia in healthy and diseased rodents (n = 6). To healthy mice, 3TC (20 mg/kg) was administered daily for 21 days to two groups of mice with one of the groups receiving an added 10 mg/kg of AS from day 15. Another group of mice received only AS from day 15-21, while a fourth group served as saline control, and a fifth group received 5 mg/kg PM as standard. All animals were challenged with 10 ml/kg of 0.6% acetic acid solution thirty minutes after PM administration to all but the vehicle group, with all drugs administered intraperitoneally. An acute study in healthy mice was also conducted to determine the effect of AS on acetic acid mediated pain. Number of stretches over twenty minutes duration was recorded. A similar experimental protocol was set up but with animals that received cyclophosphamide-induced immunosuppression (100 mg/kg stat; 50 mg/kg on day 8) and were also inoculated with approximately 1x107 Plasmodium berghei parasites. Analgesia was evaluated on days 15 and 21 in the healthy animals and on day 15 in the diseased animals. In the acute study AS showed analgesic activity which was diminished in the presence of 3TC. PM-mediated analgesia was also significantly decreased by the 3TC-AS (P<0.01, ANOVA and Dunnett’s test) in healthy mice, but not significantly in diseased animals (despite reduction in analgesic effect). Data from this study suggests the possible need for caution or alternate analgesic medication with 3TC-AS co administration.