Lamivudine: What It Is and How It Helps

Lamivudine is a common antiviral used to treat HIV and chronic hepatitis B. It works by blocking the virus from copying itself. Doctors often prescribe it as part of a combination plan; using lamivudine alone for HIV can cause resistance.

Doses and how to take

Typical adult dose for HIV is 150 mg twice daily or 300 mg once daily as a combined pill. For hepatitis B the usual dose is 100 mg once daily. Your doctor will pick the dose based on your diagnosis, other meds, and kidney function. If you have kidney disease your dose may need to be lowered.

Side effects and safety

Side effects are usually mild. The most common ones are headache, tiredness, nausea, and stomach pain. Rare but serious reactions include liver problems, lactic acidosis, and worsening hepatitis B after stopping the drug. If you notice dark urine, yellowing skin or eyes, severe stomach pain, or fast breathing, get medical help right away.

Take lamivudine exactly as prescribed. Missing doses can let the virus rebound and lead to resistance. If you forget one dose, take it as soon as you remember unless it is almost time for the next dose. Do not double up.

Lamivudine interacts with fewer drugs than some antivirals, but interactions still matter. Tell your doctor about all medicines you use, especially other antivirals, chemotherapy drugs, and some antibiotics. Combining lamivudine with other nucleoside reverse transcriptase inhibitors is common; doctors balance effectiveness and side effect risks when choosing combinations.

Pregnancy and breastfeeding: Lamivudine is often used during pregnancy to lower the risk of mother-to-child HIV transmission. Still, talk to your obstetrician and infectious disease provider about risks and benefits. If you are breastfeeding and have HIV, local guidelines and your clinician will advise whether breastfeeding is safe or if alternatives are needed.

Testing and monitoring help keep treatment safe. Before and during treatment your doctor may check liver function, kidney function, and viral load. For hepatitis B patients, stopping lamivudine can trigger flare-ups, so supervised stopping is important.

Resistance can develop, especially with poor adherence or monotherapy. Doctors monitor viral load; if lamivudine stops working they may switch drugs or add others. Some resistant strains may respond to other approved antivirals, but options depend on prior treatment and resistance tests.

Storing lamivudine is simple: keep it at room temperature, away from moisture and heat. Keep pills in their original bottle and out of reach of children.

If cost is an issue, ask about generic lamivudine, patient assistance programs, or local health services that help with HIV and hepatitis medications. Always buy medicines from reputable pharmacies.

Questions to ask your doctor: Why is lamivudine right for me? How long will I take it? What tests will you do while I'm on it? What side effects should prompt a call? Good answers make treatment safer and easier to stick with.

This page gives practical facts but does not replace medical advice. For personal guidance, talk to your healthcare provider. Need help finding a clinic or low-cost options? We can point you today.