Cimduo Side Effects

Generic name: lamivudine / tenofovir disoproxil

Medically reviewed by Drugs.com. Last updated on Mar 28, 2025.

Note: This document provides detailed information about Cimduo Side Effects associated with lamivudine / tenofovir disoproxil. Some dosage forms listed on this page may not apply specifically to the brand name Cimduo.

Applies to lamivudine / tenofovir disoproxil: oral tablet.

Precautions

It is very important that your doctor check you and your child's progress at regular visits, especially during the first few weeks that you take this medicine. Blood and urine tests may be needed to check for any unwanted effects.

Do not take Temixys™ together with adefovir (Hepsera®).

Two rare but serious reactions to this medicine are lactic acidosis (too much acid in the blood) and liver toxicity. Call your doctor right away if you or child have abdominal or stomach discomfort, cramping, nausea, vomiting, diarrhea, or a decreased appetite, muscle cramping or pain, unusual tiredness or weakness, trouble breathing, or yellow skin or eyes.

This medicine may cause a hepatitis B infection to worsen if you stop using it. Your doctor may check for the presence of hepatitis B before and during treatment with this medicine and for at least several months after your last dose.

This medicine may increase the risk of kidney problems. To lower this risk, avoid other medicines that can be harmful to the kidneys such as aminoglycoside antibiotics, certain other antiviral medicines, and NSAID pain medicines.

Check with your doctor right away if you or your child have loss of appetite, nausea, or pains in the stomach, side, or abdomen, possibly radiating to the back. These could be symptoms of pancreatitis (swelling of the pancreas).

This medicine may also increase your or your child's risk of developing fractures (broken bones). Ask your doctor about this if you have any concerns.

Your immune system may get stronger when you start using HIV medicines. Tell your doctor right away if you notice any changes in your health. Sometimes the immune system will start to fight infections that were hidden in your body, such as pneumonia, herpes, or tuberculosis. Autoimmune disorders (eg, Graves' disease, polymyositis, and Guillain-Barré syndrome) may also occur.

This medicine may cause you to have excess body fat. Tell your doctor if you notice changes in your body shape, such as an increased amount of fat in the upper back and neck, or around the chest and stomach area. You might also lose fat from the legs, arms, and face.

This medicine does not decrease the risk of transmitting the HIV infection to others through sexual contact or by contaminated blood. Make sure you understand and practice safe sex, even if your partner also has HIV. Avoid sharing needles with anyone.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (St. John's wort) or vitamin supplements.

Serious side effects of Cimduo

Along with its needed effects, lamivudine / tenofovir disoproxil may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking lamivudine / tenofovir disoproxil:

Other side effects of Cimduo

Some side effects of lamivudine / tenofovir disoproxil may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

For healthcare professionals

Applies to lamivudine / tenofovir disoproxil: oral tablet.

General adverse events

In a controlled trial with lamivudine, tenofovir disoproxil fumarate (DF), and efavirenz, the most common side effects were mild-to-moderate gastrointestinal events and dizziness. Mild side effects (grade 1) were common and included dizziness, diarrhea, and nausea.^[Ref]

Metabolic

• Very common (10% or more): Elevated fasting cholesterol (19%)
• Uncommon (0.1% to 1%): Lipodystrophy, elevated fasting triglycerides
• Frequency not reported: Higher 1,25 vitamin D levels

Lamivudine:

• Very rare (less than 0.01%): Lactic acidosis
• Postmarketing reports: Hyperglycemia, lactic acidosis, redistribution/accumulation of body fat

Tenofovir DF:

• Very common (10% or more): Hypophosphatemia
• Uncommon (0.1% to 1%): Hypokalemia
• Rare (0.01% to 0.1%): Lactic acidosis
• Postmarketing reports: Lactic acidosis, hypokalemia, hypophosphatemia

Antiretroviral therapy:

• Frequency not reported: Increased glucose levels

Combination antiretroviral therapy:

• Frequency not reported: Redistribution/accumulation of body fat (including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, "cushingoid appearance")^[Ref]

Elevated fasting cholesterol (greater than 240 mg/dL) and fasting triglycerides (greater than 750 mg/dL) have been reported in 19% and 1% of patients using lamivudine, tenofovir DF, and efavirenz, respectively.

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) have been reported with the use of nucleoside analogs.

Hypokalemia and hypophosphatemia have occurred as a result of proximal renal tubulopathy.^[Ref]

Dermatologic

• Very common (10% or more): Rash event (included rash, pruritus, maculopapular rash, urticaria, vesiculobullous rash, pustular rash; 18%)

Lamivudine:

• Common (1% to 10%): Rash, alopecia
• Rare (0.01% to 0.1%): Angioedema
• Postmarketing reports: Urticaria, alopecia, pruritus

Tenofovir DF:

• Very common (10% or more): Rash
• Rare (0.01% to 0.1%): Angioedema
• Postmarketing reports: Rash^[Ref]

Nervous system

• Very common (10% or more): Headache (14%)
• Common (1% to 10%): Dizziness
• Uncommon (0.1% to 1%): Peripheral neuropathy (included peripheral neuritis, neuropathy)

Lamivudine:

• Common (1% to 10%): Headache
• Very rare (less than 0.01%): Peripheral neuropathy/paresthesia

Tenofovir DF:

• Very common (10% or more): Dizziness
• Common (1% to 10%): Headache^[Ref]

Other

• Very common (10% or more): Pain (13%)
• Common (1% to 10%): Fever, asthenia

Lamivudine:

• Common (1% to 10%): Fatigue, malaise, fever
• Postmarketing reports: Weakness

Tenofovir DF:

• Very common (10% or more): Asthenia
• Common (1% to 10%): Fatigue
• Postmarketing reports: Asthenia

Antiretroviral therapy:

• Frequency not reported: Increased weight, increased blood lipid levels^[Ref]

Musculoskeletal

• Very common (10% or more): Elevated creatine phosphokinase (12%)
• Common (1% to 10%): Back pain, arthralgia, myalgia
• Frequency not reported: Decreased bone mineral density, increased biochemical markers of bone metabolism (serum bone-specific alkaline phosphatase, serum osteocalcin, serum C telopeptide, urinary N telopeptide), clinically relevant fractures (excluding fingers and toes)

Lamivudine:

• Common (1% to 10%): Arthralgia, muscle disorders
• Rare (0.01% to 0.1%): Rhabdomyolysis
• Postmarketing reports: Muscle weakness, elevated creatine phosphokinase, rhabdomyolysis

Tenofovir DF:

• Uncommon (0.1% to 1%): Rhabdomyolysis, muscular weakness
• Rare (0.01% to 0.1%): Myopathy
• Frequency not reported: Bone abnormalities (infrequently contributed to fractures)
• Postmarketing reports: Rhabdomyolysis, osteomalacia (manifested as bone pain and infrequently contributed to fractures), muscular weakness, myopathy

Combination antiretroviral therapy:

• Frequency not reported: Osteonecrosis^[Ref]

Elevated creatine phosphokinase (males: greater than 990 units/L; females: greater than 845 units/L) has been reported in 12% of patients using lamivudine, tenofovir DF, and efavirenz.

Proximal renal tubulopathy (including Fanconi syndrome) sometimes leading to bone abnormalities (infrequently contributing to fractures) has been reported.

Rhabdomyolysis, osteomalacia, muscular weakness, and myopathy have occurred as a result of proximal renal tubulopathy.^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (11%)
• Common (1% to 10%): Nausea, increased serum amylase, abdominal pain, vomiting, dyspepsia

Lamivudine:

• Common (1% to 10%): Nausea, vomiting, abdominal pain/cramps, diarrhea
• Rare (0.01% to 0.1%): Pancreatitis, elevated serum amylase

Tenofovir DF:

• Very common (10% or more): Diarrhea, vomiting, nausea
• Common (1% to 10%): Abdominal pain, abdominal distension, flatulence
• Uncommon (0.1% to 1%): Pancreatitis
• Postmarketing reports: Pancreatitis, increased amylase, abdominal pain^[Ref]

Increased serum amylase (greater than 175 units/L) has been reported in 9% of patients using lamivudine, tenofovir DF, and efavirenz.

Pancreatitis (some cases fatal) has been reported in antiretroviral nucleoside-experienced pediatric patients using lamivudine alone or in combination with other antiretroviral agents.^[Ref]

Psychiatric

• Very common (10% or more): Depression (11%)
• Common (1% to 10%): Anxiety, insomnia

Lamivudine:

• Common (1% to 10%): Insomnia^[Ref]

Genitourinary

• Common (1% to 10%): Hematuria

Tenofovir DF:

• Postmarketing reports: Proteinuria, polyuria^[Ref]

Hematuria (greater than 100 RBC/high power field) has been reported in 7% of patients using lamivudine, tenofovir DF, and efavirenz.^[Ref]

Hepatic

• Common (1% to 10%): Elevated AST, elevated ALT

Lamivudine:

• Uncommon (0.1% to 1%): Transient elevated liver enzymes (AST, ALT)
• Rare (0.01% to 0.1%): Hepatitis
• Postmarketing reports: Hepatic steatosis, posttreatment exacerbation of hepatitis B

Tenofovir DF:

• Common (1% to 10%): Increased transaminases
• Rare (0.01% to 0.1%): Hepatic steatosis, hepatitis
• Frequency not reported: Acute exacerbation of hepatitis
• Postmarketing reports: Hepatic steatosis, hepatitis, increased liver enzymes (most commonly AST, ALT, GGT)

Combination antiretroviral therapy:

• Frequency not reported: Hepatic decompensation^[Ref]

Elevated AST (males: greater than 180 units/L; females: greater than 170 units/L) and ALT (males: greater than 215 units/L; females: greater than 170 units/L) have been reported in 5% and 4% patients using lamivudine, tenofovir DF, and efavirenz, respectively.

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) have been reported with the use of nucleoside analogs.

Severe acute exacerbations of hepatitis B have been reported in patients coinfected with HIV-1 and hepatitis B virus after discontinuation of lamivudine or tenofovir DF.

Hepatic decompensation (some fatal) has been reported in patients coinfected with HIV-1 and hepatitis C receiving combination antiretroviral therapy for HIV-1 and interferon alfa with or without ribavirin.^[Ref]

Hematologic

• Common (1% to 10%): Decreased neutrophils

Lamivudine:

• Uncommon (0.1% to 1%): Neutropenia, anemia, thrombocytopenia
• Very rare (less than 0.01%): Pure red cell aplasia
• Postmarketing reports: Anemia (including pure red cell aplasia and severe anemias progressing on therapy)^[Ref]

Decreased neutrophils (less than 750/mm3) has been reported in 3% of patients using lamivudine, tenofovir DF, and efavirenz.

Severe neutropenia and severe anemia have been reported occasionally with lamivudine.^[Ref]

Respiratory

• Common (1% to 10%): Pneumonia

Lamivudine:

• Common (1% to 10%): Cough, nasal symptoms

Tenofovir DF:

• Postmarketing reports: Dyspnea^[Ref]

Renal

Tenofovir DF:

• Uncommon (0.1% to 1%): Increased creatinine, proximal renal tubulopathy (including Fanconi syndrome)
• Rare (0.01% to 0.1%): Renal impairment, renal failure, acute renal failure, acute tubular necrosis, nephrogenic diabetes insipidus
• Postmarketing reports: Renal insufficiency, acute renal failure, renal failure, acute tubular necrosis, Fanconi syndrome, proximal renal tubulopathy, interstitial nephritis (including acute cases), nephrogenic diabetes insipidus, increased creatinine, nephritis (including acute interstitial nephritis)^[Ref]

Proximal renal tubulopathy generally resolved or improved after tenofovir DF was stopped; however, decreased CrCl did not completely resolve in some patients after stopping tenofovir DF. Patients at risk of renal dysfunction (e.g., baseline renal risk factors, advanced HIV disease, concomitant nephrotoxic drugs) were at increased risk of incomplete recovery of renal function despite stopping tenofovir DF.

Rhabdomyolysis, osteomalacia, bone abnormalities (infrequently contributing to fractures), hypokalemia, muscular weakness, myopathy, and hypophosphatemia have occurred as a result of proximal renal tubulopathy.^[Ref]

Hypersensitivity

Lamivudine:

• Postmarketing reports: Anaphylaxis

Tenofovir DF:

• Postmarketing reports: Allergic reaction (including angioedema)^[Ref]

Immunologic

• Frequency not reported: Immune reconstitution/reactivation syndrome, autoimmune disorders in the setting of immune reconstitution (e.g., Graves' disease, polymyositis, Guillain-Barre syndrome, autoimmune hepatitis)^[Ref]

Endocrine

• Frequency not reported: Higher serum parathyroid hormone levels^[Ref]

See also:

Frequently asked questions

• How much does HIV treatment Cimduo cost?
• What drugs are contained in the HIV treatment Cimduo?
• What is the difference between HIV treatments Symfi and Symfi Lo?

Further information

Cimduo side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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