Efavirenz / Lamivudine / Tenofovir Dosage

Medically reviewed by Drugs.com. Last updated on Nov 30, 2022.

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.

Frequently asked questions

• What is the difference between HIV treatments Symfi and Symfi Lo?
• What drugs are contained in the HIV treatment Symfi Lo?

Further information

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

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