Key takeaways
Abacavir (Ziagen) and tenofovir alafenamide (Vemlidy) are both antiretroviral (ARV) medications used to treat viral infections, but they are used for different conditions. Abacavir is primarily used as part of combination treatments for HIV, while tenofovir alafenamide is used for hepatitis B virus (HBV) and is also part of combination treatments for HIV. Both medications belong to the nucleoside reverse transcriptase inhibitor (NRTI) class, which works by blocking the virus from making copies of itself. Abacavir is available in both tablet and oral solution forms and can be taken once or twice daily, while tenofovir alafenamide is taken as a tablet once daily with food. Abacavir is available as a generic, whereas tenofovir alafenamide is only available as a brand-name medication. Abacavir requires a genetic test before use due to the risk of a severe allergic reaction, while tenofovir alafenamide has a risk of kidney and bone issues. Common side effects of abacavir include headache and nausea, whereas tenofovir alafenamide may cause headache and stomach pain. Additionally, tenofovir alafenamide should not be used alone for HIV treatment, as it can lead to resistance.
