How antiretroviral therapy prolongs life
With the development of safe and effective drugs, however, people infected with HIV (human immunodeficiency virus) now have longer and healthier lives. Antiretroviral therapy can prolong the lives of many HIV/AIDS infected individuals. There are four types of ARV drugs:
l Nucleoside reverse transcriptase inhibitors (NRTIs) such as Zidovudine (formerly called azidothymidine, AZT) interfere with HIV-1 replication by inhibiting viral reverse transcriptase, RT (see diagram).
l Non-nucleoside reverse transcriptase inhibitors (NNRTIs) cause conformational changes at the active site of reverse transcriptase thereby inhibiting its activity.
l Protease inhibitors such as indinavir, ritonavir and nelfinavir prevent the cutting of the precursor polypeptide that is processed into smaller core proteins.
l Entry inhibitors: these drugs prevent the passage of HIV into host cells.
Monotherapy has limited success due to the rapid development of resistant HIV strains. Triple combination therapy or highly active antiretroviral therapy (HAART) significantly reduces viral load. The cost of HAART has been reduced with the manufacture of generic drugs.
HAART is now known to be accompanied by fatal metabolic complications that result in conditions such as decreased bone strength, lactic acidosis, diabetes mellitus, pancreatitis, lipodystrophy, obesity, brain damage, bleeding inside the brain caused by ruptured blood vessels, stroke and heart attack.
In Zambia, Dr Manasseh Phiri reported that these adverse drug reactions such as obesity may bring a new wave of stigma whereby people may be able to tell by looks persons that are on treatment.
l Kazhila Chinsembu is a lecturer at the University of Namibia, Windhoek. Email: firstname.lastname@example.org