What the label lists and what reports show
Lamivudine side effects
Lamivudine's FDA label: “The most common reported adverse reactions (incidence greater than equal to 15%) in adults were headache, nausea, malaise and fatigue, nasal signs and symptoms, diarrhea, and cough.” FAERS holds 25,152 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is virologic failure (1,899 reports).
- Generic listed
- Boxed warning
Check it at the source: the lamivudine FDA label on DailyMed (effective January 5, 2026, Strides Pharma Science Limited); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of lamivudine tablets ?Lamivudine tablets can cause serious side effects including: See "What is the most important information I should know about lamivudine tablets ?" Build-up of an acid in your blood (lactic acidosis). Lactic acidosis can happen in some people who take lamivudine tablets. Lactic acidosis is a serious medical emergency that can cause death. Call your healthcare provider right away if you get any of the following symptoms that could be signs of lactic acidosis: feel very weak or tired feel cold, especially in your arms and legs unusual (not normal) muscle pain feel dizzy or light-headed trouble breathing have a fast or irregular heartbeat stomach pain with nausea and vomiting Serious liver problems can happen in people who take lamivudine tablets. In some cases these serious liver problems can lead to death. […]
Source: FDA drug label, Strides Pharma Science Limited, effective January 5, 2026 (SPL set ac824c7e-9c9f-487b-ad2f-d50eaef5cbda), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common reported adverse reactions (incidence greater than equal to 15%) in adults were headache, nausea, malaise and fatigue, nasal signs and symptoms, diarrhea, and cough.
Table 3. Selected Clinical Adverse Reactions (Greater than or Equal to 5% Frequency) in Four Controlled Clinical Trials (NUCA3001, NUCA3002, NUCB3001, NUCB3002)
| Adverse Reaction | Lamivudine 150 mg Twice Daily plus RETROVIR (n = 251) | RETROVIR Either zidovudine monotherapy or zidovudine in combination with zalcitabine. (n… |
|---|---|---|
| Headache | 35% | 27% |
| Malaise & fatigue | 27% | 23% |
| Fever or chills | 10% | 12% |
| Nausea | 33% | 29% |
| Diarrhea | 18% | 22% |
| Nausea & vomiting | 13% | 12% |
| Anorexia and/or decreased appetite | 10% | 7% |
| Abdominal pain | 9% | 11% |
| Abdominal cramps | 6% | 3% |
| Dyspepsia | 5% | 5% |
| Neuropathy | 12% | 10% |
| Insomnia & other sleep disorders | 11% | 7% |
| Dizziness | 10% | 4% |
| Depressive disorders | 9% | 4% |
| Nasal signs & symptoms | 20% | 11% |
| Cough | 18% | 13% |
| Skin rashes | 9% | 6% |
| Musculoskeletal pain | 12% | 10% |
| Myalgia | 8% | 6% |
| Arthralgia | 5% | 5% |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following adverse reactions are discussed in other sections of the labeling: Exacerbations of hepatitis B [see Boxed Warning, Warnings and Precautions (5.1)]. Lactic acidosis and severe hepatomegaly with steatosis [see Warnings and Precautions (5.2)]. Pancreatitis [see Warnings and Precautions (5.3)]. Immune reconstitution syndrome [see Warnings and Precautions (5.4)]. The most common reported adverse reactions (incidence greater than equal to 15%) in adults were headache, nausea, malaise and fatigue, nasal signs and symptoms, diarrhea, and cough. (6.1) The most common reported adverse reactions (incidence greater than equal to 15%) in pediatric patients subjects were fever and cough. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Strides Pharma Inc. at 1-877-244-9825 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Clinical Trials Experience in Adult Subjects. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. …
Source: FDA drug label, Strides Pharma Science Limited, effective January 5, 2026 (SPL set ac824c7e-9c9f-487b-ad2f-d50eaef5cbda), via openFDA; the full label on DailyMed
What do FAERS reports show?
25,152 reports list lamivudine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 3,540 are coded as a death and 6,944 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 15 reactions below, 7 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Lamivudine: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions