Lamivudine Dosage

This dosage information may not include all the information needed to use Lamivudine safely and effectively. See additional information for Lamivudine.

The information at Drugs.com is not a substitute for medical advice. ALWAYS consult your doctor or pharmacist.

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for HIV Infection

300 mg daily, administered as either 150 mg orally every 12 hours or 300 mg orally every 24 hours

Usual Adult Dose for Nonoccupational Exposure

150 mg orally twice a day or 300 mg orally every 24 hours plus efavirenz plus (zidovudine or tenofovir)
Prophylaxis should be initiated as soon as possible, within 72 hours of exposure.

Duration: 28 days

Usual Adult Dose for Occupational Exposure

Basic regimen for HIV postexposure prophylaxis: 150 mg orally twice a day or 300 mg orally every 24 hours plus zidovudine or stavudine
Therapy should begin promptly, preferably within 1 to 2 hours postexposure.

Duration: Generally 28 days; however, the exact duration of therapy may differ based on the institution's protocol.

Usual Adult Dose for Chronic Hepatitis B

100 mg orally every 24 hours

Duration: Safety and effectiveness of treatment beyond one year have not been established. The optimum duration of treatment is not known.

Usual Pediatric Dose for HIV Infection

Oral solution:
Less than 4 weeks: 2 mg/kg orally twice a day has been recommended
1 month to less than 3 months: 4 mg/kg orally twice a day has been recommended
3 months to less than 16 years: 4 mg/kg orally twice a day; maximum of 150 mg/dose

16 years or older:
Less than 50 kg: 4 mg/kg orally twice a day; maximum of 150 mg/dose
50 kg or more: 150 mg orally twice a day or 300 mg orally once a day

Tablets:
14 to 21 kg: 75 mg orally twice a day (AM and PM)
Greater than 21 to less than 30 kg: 75 mg orally in the AM and 150 mg in the PM
30 kg or more: 150 mg orally twice a day (AM and PM)

Usual Pediatric Dose for Chronic Hepatitis B

2 years or older: 3 mg/kg orally every 24 hours
Maximum dose: 100 mg orally every 24 hours

Duration: Safety and effectiveness of treatment beyond one year have not been established. The optimum duration of treatment is not known.

Renal Dose Adjustments

Adult:
CrCl 30 to 49 mL/min:
HIV Infection/Occupational Exposure: 150 mg orally every 24 hours
Chronic Hepatitis B: 100 mg orally the first dose, then 50 mg orally every 24 hours

CrCl 15 to 29 mL/min:
HIV Infection/Occupational Exposure: 150 mg orally as the first dose, then 100 mg orally every 24 hours
Chronic Hepatitis B: 100 mg orally the first dose, then 25 mg orally every 24 hours

CrCl 5 to 14 mL/min:
HIV Infection/Occupational Exposure: 150 mg orally as the first dose, then 50 mg orally every 24 hours
Chronic Hepatitis B: 35 mg orally the first dose, then 15 mg orally every 24 hours

CrCl less than 5 mL/min:
HIV Infection/Occupational Exposure: 50 mg orally as the first dose, then 25 mg orally every 24 hours
Chronic Hepatitis B: 35 mg orally the first dose, then 10 mg orally every 24 hours

Adolescents 30 kg or more:
HIV Infection:
CrCl 30 to 49 mL/min: 150 mg orally every 24 hours
CrCl 15 to 29 mL/min: 150 mg orally as the first dose, then 100 mg orally every 24 hours
CrCl 5 to 14 mL/min: 150 mg orally as the first dose, then 50 mg orally every 24 hours
CrCl less than 5 mL/min or less: 50 mg orally as the first dose, then 25 mg orally every 24 hours

Pediatric: There are insufficient data to recommend a specific dose adjustment; however, a reduction in the dose and/or an increase in the dosing interval should be considered.

Liver Dose Adjustments

No adjustment recommended. Safety and efficacy have not been established in patients with decompensated liver disease.

Precautions

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination with other antiretroviral agents. Risk factors may include female gender, obesity, and prolonged nucleoside exposure. Caution is recommended in patients with risk factors for liver disease; however, cases have also been reported in patients with no known risk factors. Treatment should be suspended in any patient who develops clinical or laboratory signs suggestive of lactic acidosis or pronounced hepatomegaly.

HIV counseling and testing should be offered to all patients before beginning lamivudine for hepatitis B virus infection (HBV) and periodically during treatment. Epivir-HBV tablets and oral solution contain a lower dose of the same active ingredient in Epivir tablets and oral solution for HIV. If treatment with Epivir-HBV is prescribed for chronic HBV for a patient with unrecognized or untreated HIV infection, rapid emergence of HIV resistance will likely occur due to a subtherapeutic dose and inappropriate monotherapy. Likewise, if lamivudine is prescribed to an individual coinfected with HIV and HBV, the Epivir brand, not Epivir-HBV, should be used. The safety and efficacy of lamivudine in the treatment of coinfected patients have not been established.

Severe acute exacerbations of hepatitis, including fatalities, have been reported in patients with HBV (including those coinfected with HIV-1) who have discontinued antihepatitis B therapy, including lamivudine. Patients who discontinue antihepatitis B therapy should have close monitoring of hepatic function with clinical and laboratory follow-up for at least several months. If appropriate, resumption of antihepatitis B therapy may be necessary.

Pancreatitis has been reported, particularly in HIV-infected pediatric patients with prior nucleoside analog exposure. Patients should be monitored for pancreatitis and lamivudine should be discontinued immediately if clinical or laboratory signs of pancreatitis develop.

Immune reconstitution syndrome has occurred during combination antiretroviral therapy. Patients responding to therapy may develop an inflammatory response to indolent or residual opportunistic infections and require evaluation and treatment.

The potential for HIV cross-resistance among nucleoside reverse transcriptase inhibitors exists but has not been fully explored. It is unknown what effect lamivudine therapy will have on the activity of subsequently administered nucleoside reverse transcriptase inhibitors. Selection of antiretroviral agents for a patient's medication regimen should be done carefully and in consultation with an infectious disease specialist.

Due to high rates of resistance development in treated patients, initiation of lamivudine therapy for chronic HBV should only be considered when an alternative antiviral with a higher genetic barrier to resistance is not available or appropriate. Patients should be advised that lamivudine is not a cure for HBV and that the long-term benefits of treatment have not been established, especially with regard to hepatocellular carcinoma and decompensated cirrhosis. Resistant hepatitis B virus may emerge and disease may worsen during treatment.

Due to similar resistance profiles and lack of therapeutic benefit, the concomitant use of lamivudine and emtricitabine-containing medications is not recommended.

Related drugs not for coadministration with lamivudine include abacavir-lamivudine, abacavir/lamivudine/zidovudine, and lamivudine-zidovudine, in which lamivudine is one of the active components. Lamivudine and lamivudine-HBV should not be taken together.

Safety and efficacy of lamivudine-HBV have not been established in patients with decompensated liver disease or organ transplants; pediatric patients less than 2 years of age; or patients coinfected with HBV and hepatitis C virus, hepatitis delta, or HIV.

Dialysis

Adult:
Conventional 4-hour hemodialysis and peritoneal dialysis (CAPD and APD): No additional dose adjustments recommended after adjustment for creatinine clearance.
Prolonged or continuous hemodialysis: Data not available

Pediatric: Data not available

Other Comments

Lamivudine should be used in combination with other antiretroviral agents.

Lamivudine oral solution is preferred for patients unable to reliably swallow tablets.

Patients with diabetes should be aware that lamivudine oral solution contains sucrose (Epivir HBV: 4 g sucrose per 20 mL; Epivir: 3 g sucrose per 15 mL).

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