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Efavirenz Side Effects

Medically reviewed by Last updated on Dec 27, 2023.

Applies to efavirenz: oral tablet.

Serious side effects of Efavirenz

Along with its needed effects, efavirenz 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 efavirenz:

More common

Less common


Incidence not known

Other side effects of Efavirenz

Some side effects of efavirenz 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:

More common

Less common or rare

Incidence not known

For Healthcare Professionals

Applies to efavirenz: oral capsule, oral tablet.


The most significant side effects included nervous system symptoms, psychiatric symptoms, and rash. The most common side effects (at least moderate severity) were impaired concentration, abnormal dreams, rash, dizziness, nausea, headache, fatigue, insomnia, and vomiting in patients using this drug in combination with lamivudine-zidovudine or indinavir.

Administration of this drug with food may increase drug exposure and may increase the rate of side effects (especially nervous system symptoms).[Ref]


Increased nonfasting serum cholesterol and HDL have been reported; clinical significance unknown.

Increased nonfasting triglycerides (at least 751 mg/dL) and glucose (greater than 250 mg/dL) have been reported in up to 11% and up to 5% of patients, respectively.[Ref]

Very common (10% or more): Increased nonfasting serum cholesterol (up to 54%), increased HDL (up to 35%), increased nonfasting triglycerides (up to 11%)

Common (1% to 10%): Increased glucose, anorexia, hypertriglyceridemia, decreased weight (included cachexia/wasting), weight gain, weight loss

Uncommon (0.1% to 1%): Hypercholesterolemia

Frequency not reported: Redistribution/accumulation of body fat (including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, "cushingoid appearance"), insulin resistance, hyperglycemia, hyperlactatemia, alcohol intolerance, increased appetite[Ref]

Nervous system

Nervous system symptoms generally began the first or second day of therapy and often resolved after 2 to 4 weeks. Nervous system symptoms of any grade and regardless of causality (52.7%) included dizziness, insomnia, impaired concentration, somnolence, abnormal dreams, hallucinations, amnesia, agitation, euphoria, depersonalization, confusion, abnormal thinking, and stupor during clinical trials with this drug in combination with other antiretroviral agents. These symptoms were mild in 33.3%, moderate in 17.4%, and severe in 2% of patients. Therapy was discontinued in 2.1% of patients due to these side effects.

Side effects of moderate or severe intensity included dizziness (up to 9%), headache (up to 8%), impaired concentration (up to 5%), and somnolence (up to 2%).

Vacuolar axonopathy and hypersomnolence leading to coma and death was reported in a patient with elevated drug levels.[Ref]

Very common (10% or more): Dizziness (included lightheadedness/fainting; up to 28.1%)

Common (1% to 10%): Impaired concentration, headache, somnolence, disturbance in attention, paresthesia (included numbness/tingling)

Uncommon (0.1% to 1%): Agitation, amnesia, ataxia, abnormal coordination, convulsions, abnormal thinking, vertigo, taste perversion

Frequency not reported: Depersonalization, confusion, stupor, impaired attention span, impaired coordination, migraine headaches, neuralgia, peripheral neuropathy, speech disorder, parosmia, vacuolar axonopathy and hypersomnolence leading to coma and death

Postmarketing reports: Cerebellar coordination and balance disturbances, hypoesthesia, neuropathy, tremor, tinnitus[Ref]


Very common (10% or more): Skin rash of any grade (26.3%), rash (included erythema multiforme, rash, erythematous rash, follicular rash, maculopapular rash, petechial rash, pustular rash, urticaria, macules, papules, erythema, redness, inflammation, allergic rash, welts, hives, itchy, pruritus; up to 16%), grade 2 rash (diffuse maculopapular rash, dry desquamation; 14.7%), grade 1 rash (erythema, pruritus; 10.7%)

Common (1% to 10%): Pruritus, increased sweating, urticaria (included allergic rash/welts/hives), erythema/redness/inflammation, blisters/ulcerations/lesions, dry skin

Uncommon (0.1% to 1%): Grade 3 rash (vesiculation, moist desquamation, ulceration), grade 4 rash (erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, necrosis requiring surgery, exfoliative dermatitis)

Frequency not reported: Nail disorders, skin discoloration, leukocytoclastic vasculitis

Postmarketing reports: Erythema multiforme, photoallergic dermatitis, Stevens-Johnson syndrome[Ref]

Rashes were usually mild-to-moderate maculopapular skin eruptions. The median time to onset of rash in adults was 11 days. In most patients, the rash resolved within 1 month despite continued use of the drug. Treatment was discontinued in 1.7% of patients due to rash.

There was limited experience using this drug in patients who previously discontinued other nonnucleoside reverse transcriptase inhibitors due to rash. In 19 such patients formerly on nevirapine, about half developed a mild to moderate rash; 2 of those patients discontinued therapy because of the rash.[Ref]


Very common (10% or more): Depression (up to 19%), insomnia (included dreams/sleeping problems; up to 16.3%), anxiety (up to 13%)

Common (1% to 10%): Nervousness (included agitation/hyperactive), abnormal dreams, severe depression, hallucinations

Uncommon (0.1% to 1%): Affect lability, confusional state, euphoric mood, suicidal ideation, nonfatal suicide attempts, aggressive behavior, paranoid reactions, manic reactions, drug abuse

Frequency not reported: Obsessive disorder, irritability, mood changes, vivid dreams, nightmares, delirium, increased libido, decreased libido, aggravated depression, apathy

Postmarketing reports: Aggressive reactions, agitation, delusions, emotional lability, mania, neurosis, paranoia, psychosis, completed suicide, psychosis-like behavior[Ref]

Psychiatric symptoms generally began the first or second day of therapy and often resolved after 2 to 4 weeks. Patients with history of psychiatric disorders were at greater risk of serious psychiatric side effects. Psychiatric side effects classified as serious during controlled trials included severe depression, suicidal ideation, nonfatal suicide attempts, aggressive behavior, paranoid reactions, and manic reactions. One percent of patients discontinued or interrupted therapy due to at least 1 of these side effects.

Side effects of moderate or severe intensity included insomnia (up to 7%), depression (up to 5%), anxiety (up to 4%), abnormal dreams (up to 3%), and nervousness (up to 2%).[Ref]


Very common (10% or more): Diarrhea (up to 14%)

Common (1% to 10%): Nausea (included nausea/vomiting), vomiting, elevated amylase, dyspepsia, abdominal pain (included groin/pelvic pain), constipation

Uncommon (0.1% to 1%): Pancreatitis, flatulence

Frequency not reported: Asymptomatic increases in serum amylase levels, gastritis, gastroenteritis, gastroesophageal reflux, dry mouth, burning mouth syndrome

Postmarketing reports: Malabsorption[Ref]

Elevated amylase (greater than 2 times the upper limit of normal [ULN]) has been reported in up to 6% of patients.

A 42-year-old HIV-positive woman's saquinavir in her highly active antiretroviral therapy was replaced with this drug to increase compliance. Two weeks after initiation, the patient reported severe and constant burning in her tongue, gums, and oral mucosa and was diagnosed with burning mouth syndrome (BMS). Efavirenz was discontinued and the BMS resolved within a week.[Ref]


Very common (10% or more): Pain (included flank and back pain; up to 13%)

Common (1% to 10%): Fatigue (included asthenia, malaise), edema (included enlarged/swollen, leg edema, peripheral edema), fever

Uncommon (0.1% to 1%): Asthenia

Frequency not reported: False-positive urine cannabinoid test results, vitamin D deficiency, hot flushes, malaise, influenza-like symptoms, peripheral edema, syncope

Postmarketing reports: Flushing, contraceptive failure (with an implantable hormonal contraceptive)[Ref]

False-positive urine cannabinoid test results have been observed with some screening assays in uninfected and HIV-infected subjects using this drug.[Ref]


Increased ALT, AST, and GGT to greater than 5 times ULN have each been reported in up to 8% of patients. Isolated elevations of GGT may have reflected enzyme induction not associated with liver toxicity.

During clinical trials, elevations in ALT and AST to greater than 5 times ULN occurred in 20% and 13%, respectively, of patients seropositive for hepatitis B and/or C. Therapy was discontinued in 3% of coinfected patients due to liver or biliary system disorders.

Some of the postmarketing reports of hepatic failure occurred in patients with no preexisting liver disease or other identifiable risk factors.[Ref]

Common (1% to 10%): Increased ALT, increased AST, increased GGT

Frequency not reported: Acute hepatitis

Postmarketing reports: Hepatic failure (a few reports were characterized by a fulminant course, with some cases progressing to transplantation or death), hepatic enzyme increase, hepatitis[Ref]


Common (1% to 10%): Neutropenia

Rare (less than 0.1%): Hemolytic anemia[Ref]

Neutropenia (less than 750/mm3) was reported in up to 10% of patients.[Ref]


Common (1% to 10%): Cardiovascular dysfunction

Frequency not reported: QT interval prolongation, torsades de pointes, tachycardia, thrombophlebitis

Postmarketing reports: Palpitations[Ref]


Uncommon (0.1% to 1%): Hypersensitivity

Frequency not reported: Skin rash, eosinophilia, and systemic involvement (lymphadenopathy, interstitial nephritis, pneumonia, pulmonary infiltration, hepatitis, fever, rigor, myalgia, arthralgias)

Postmarketing reports: Allergic reactions[Ref]


Uncommon (0.1% to 1%): Hematuria

Rare (less than 0.1%): Urolithiasis

Frequency not reported: Impotence

Postmarketing reports: Gynecomastia[Ref]

Analysis of a 3 mm stone, eliminated by a 47-year-old HIV-1-infected male patient, showed a stone consisting of 60% efavirenz metabolites.[Ref]


Uncommon (0.1% to 1%): Dyspnea

Frequency not reported: Asthma, sinusitis, upper respiratory tract infection[Ref]


Uncommon (0.1% to 1%): Renal calculus

Rare (less than 0.1%): Renal colic

Frequency not reported: Podocyte damage[Ref]


Uncommon (0.1% to 1%): Blurred vision

Frequency not reported: Diplopia

Postmarketing reports: Abnormal vision[Ref]


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


Frequency not reported: Osteomalacia (due to drug-induced vitamin D deficiency), osteonecrosis

Postmarketing reports: Arthralgia, myalgia, myopathy[Ref]

Frequently asked questions


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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.