Efavirenz / Lamivudine / Tenofovir Dosage

Medically reviewed by Drugs.com. Last updated on Nov 30, 2023.

Applies to the following strengths: 600 mg-300 mg-300 mg; 400 mg-300 mg-300 mg

Usual Adult Dose for HIV Infection

1 tablet orally once a day

Use: As a complete regimen for the treatment of HIV-1 infection

Usual Pediatric Dose for HIV Infection

1 tablet orally once a day

Comments:

Symfi Lo(TM) is approved for patients weighing at least 35 kg.
Symfi(TM) is approved for patients weighing at least 40 kg.
Recommended for pediatric patients who can swallow a solid tablet

Use: As a complete regimen for the treatment of HIV-1 infection

Renal Dose Adjustments

CrCl less than 50 mL/min: Not recommended.

Liver Dose Adjustments

Mild liver dysfunction: No adjustment recommended; careful monitoring recommended.
Moderate or severe liver dysfunction (Child-Pugh B or C): Not recommended.

Dose Adjustments

Concomitant rifampin:

Patients weighing at least 50 kg: Increase efavirenz dose to 800 mg once a day.

Precautions

US BOXED WARNING:

POSTTREATMENT ACUTE EXACERBATIONS OF HEPATITIS B: Severe acute exacerbations of hepatitis B reported in patients coinfected with HBV and HIV-1 who have stopped lamivudine or tenofovir disoproxil fumarate, 2 components of this drug. Hepatic function of HBV/HIV-1-coinfected patients should be monitored closely; if appropriate, antihepatitis B therapy should be started.

CONTRAINDICATIONS:

Previous hypersensitivity reaction (e.g., Stevens-Johnson syndrome, erythema multiforme, or toxic skin eruptions) to any active component or any of the ingredients
Coadministration with elbasvir-grazoprevir

Safety and efficacy have not been established in patients weighing less than 35 kg (Symfi Lo[TM]) or less than 40 kg (Symfi[TM]).

Consult WARNINGS section for additional precautions.

Dialysis

ESRD requiring hemodialysis: Not recommended.

Other Comments

Administration advice:

Test patients for HBV infection before starting this drug.
In all patients, assess serum creatinine, serum phosphorus, estimated CrCl, urine glucose, and urine protein before starting this drug and during therapy as clinically appropriate.
Monitor liver function before and during therapy.
Administer on an empty stomach, preferably at bedtime; dosing at bedtime may improve tolerability of nervous system symptoms.

Storage requirements:

Store below 30C (86F); keep bottle tightly closed.
Dispense in original bottle.

General:

Symfi Lo(TM): Each 3-drug fixed-dose combination tablet contains efavirenz 400 mg, lamivudine 300 mg, and tenofovir disoproxil fumarate 300 mg.
Symfi(TM): Each 3-drug fixed-dose combination tablet contains efavirenz 600 mg, lamivudine 300 mg, and tenofovir disoproxil fumarate 300 mg.

Monitoring:

General: Pregnancy testing in females of reproductive potential (before starting therapy)
Hepatic: Liver enzymes in all patients (before and during therapy); hepatic function of HIV-1/HBV-coinfected patients with clinical and laboratory follow-up (for at least several months after stopping therapy)
Infections/Infestations: For chronic HBV infection in all patients (before starting therapy)
Metabolic: Serum phosphorus in patients at risk of renal dysfunction (before starting and periodically during therapy); cholesterol and triglycerides (before starting and periodically during therapy)
Musculoskeletal: Bone mineral density in patients with history of pathologic bone fracture or other risk factors for osteoporosis or bone loss
Renal: Estimated CrCl in all patients (before starting and as clinically appropriate during therapy); estimated CrCl, urine glucose, and urine protein in patients at risk of renal dysfunction (before starting and periodically during therapy)

Patient advice:

Read the US FDA-approved patient labeling (Patient Information).
Avoid taking this drug with concurrent/recent use of nephrotoxic agents.
Seek medical evaluation at once if severe psychiatric side effects develop.
This drug may impair mental abilities needed to perform potentially hazardous tasks (e.g., driving, operating machinery); CNS effects may be additive if used with alcohol or psychoactive drugs. Avoid potentially hazardous tasks if CNS symptoms (e.g., dizziness, impaired concentration, drowsiness) occur.
Contact physician without delay if rash occurs.
Watch for signs of liver inflammation/failure (early signs: fatigue, weakness, lack of appetite, nausea/vomiting; later signs: jaundice, confusion, abdominal swelling, discolored feces); consult healthcare provider without delay if such symptoms occur.
Monitor pediatric patients for signs/symptoms of pancreatitis.
Notify healthcare provider at once of any symptoms of infection.