Antiretroviral Therapy may have Anxiogenic Effect on Subjects

Aims: To observe the effects of the antiretroviral drugs, Lamivudine, Zidovudine, and Efavirenz individually and in combination on locomotor behavior and anxiety.

Methods: Fifty (50) mice were divided into five (5) groups of ten (10) mice each. Group one served as control and was given normal saline. The next three groups received oral solutions of Lamivudine, Zidovudine, and Efavirenz respectively at doses of 2 mg/kg, 4 mg/kg and 8 mg/kg at volumes not exceeding 10 ml/kg body weight (i.e. 0.1 ml/10 g). The fifth group received a combined oral solution of the three antiretroviral drugs.

Results: In the Open field test, the frequency of line crossing, rearing frequency, and centre square entry are significantly (P=0.05) lower in the antiretroviral treated groups compared to the control, with a significantly higher centre square entry in the combined treated group than in the individual treated groups. In the light/dark transition box, it was observed that the duration in the light chamber was significantly (p=0.05) lower in the lamivudine and Efavirenz treated groups compared to control. The duration in the Zidovudine and combined treatment groups, though lowered, was not significantly different. There was an increase in grooming duration in the Efavirenz and the combined treatment groups, and a significant decrease in transitions in all the treatment groups compared to control. In the elevated plus maze, the frequency of open arm entry is significantly lower in the Efavirenz treated group compared to control. It is also significantly higher in the combined treatment group compared to all three individual treatment groups. The open arm duration is significantly lower in the three individual treatment groups compared to control. It is significantly lower in the Efavirenz treated group compared to the lamivudine and Zidovudine treated groups. The frequency of head dip did not differ significantly in the lamivudine and Zidovudine treated groups compared to control. It is significantly lower in the Efavirenz treated group compared to control. However it is significantly higher in the combined treatment group compared to control.

Conclusion: Taken together, our findings indicate an anxiogenic effect of antiretroviral therapy. However our results do not show a conclusive evidence that combined antiretroviral therapy has a greater anxiogenic effect on the subjects than single antiretroviral therapy.