Potential side effects and toxicity: This remains one of the most easily tolerated HIV medications. Potential side effects/toxicities (rarely seen) may include headache, nausea, vomiting, diarrhea, fever, fatigue, hair loss, insomnia, malaise (general ill feeling), nasal symptoms, cough, peripheral neuropathy, low white blood cells and anemia.
Rare but potentially fatal toxicity with all NRTIs is pancreatitis (inflammation of the pancreas), hepatomegaly with steatosis (enlarged, fatty liver) and lactic acidosis (accumulation of lactate in the blood and abnormal acid-base balance). Lactic acidosis has been seen in patients taking NRTIs but is more common and more severe in women, people who are obese and people who have been taking nukes for a long time; and more common in people with liver disease, but can occur in people without a history of liver damage. People with lactic acidosis may experience persistent fatigue, abdominal pain or distension, nausea/vomiting, and difficulty breathing or shortness of breath; and enlarged, fatty liver. Pancreatitis can be life-threatening and may cause pain in the stomach and back, along with nausea, vomiting and blood in the urine. Your physician will check for pancreatitis by checking for increased levels of amylase and lipase in the blood. Risks for pancreatitis include: higher than recommended doses of NRTIs, advanced HIV, and alcohol use. Children should be monitored carefully for pancreatitis.
Potential drug interactions: Epivir (3TC) and Emtriva (FTC) can lower the levels of Hivid, and should be avoided. No other significant drug interactions.
Tips: Exciting benefit: drug resistance that the virus develops against Epivir—the M184V mutation—makes the virus less fit to replicate and has even been shown to keep T-cells from dropping during a treatment interruption as much as they would have otherwise. It is also approved for treatment of hepatitis B virus (HBV), under the brand name Epivir HBV. So if you have hepatitis B and HIV, this drug works for both diseases, but make sure you are taking Epivir at HIV doses—always ask your doctor or pharmacist. Worsening of hepatitis B (HBV) in people co-infected with HIV/HBV has occurred when Epivir was discontinued. Epivir is also available combined with Retrovir (Combivir, one tablet twice-a-day), in a new once-a-day formula with Ziagen (Epzicom, one tablet daily) and in a triple combination with both Retrovir and Ziagen (Trizivir, one tablet twice-a-day).
Doctor
Lamivudine (3TC) is the most widely used nucleoside for good reason. It is potent and well-tolerated, has low toxicity, and can be combined with almost every other nucleoside/nucleotide except emtricitabine (Emtriva) or ddC (Hivid). It is also available in three fixed-dose-combination tablets (Combivir, Epzicom, and Trizivir). It can be dosed once or twice daily, allowing for flexible use in many regimens. Its primary weakness is a low threshold for allowing the virus to acquire a single mutation (M184V) that renders this drug ineffective. However, even if this mutation occurs, many providers elect to continue using 3TC because M184V renders the virus less “fit” (unable to make copies of itself as efficiently as wild-type virus) and also increases the virus’s susceptibility to AZT. Additionally, 3TC has activity against hepatitis B.—Chad J. Zawitz, MD
Activist
We used to think this was a wimpy drug back a few years ago, since resistance to it is developed quite easily. But we have learned that virus resistant to 3TC seems to be weaker than ones that are not, so doctors still prescribe it even if you have resistance to it (the mutation is 184V). It does not seem to cause severe side effects, although some people have reported fatigue and changes in pigmentation in the palms of their hands. It can treat hepatitis B also. It is available alone or in combination with Ziagen (Epzicom) or AZT (Combivir) or in a three-drug combo with Ziagen + AZT (Trizivir). An interesting study showed that people who have to stop their meds due to toxicity but kept taking Epivir had a lower CD4 cell drop than those who stopped all drugs.—Nelson Vergel
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