Zidovudine and Lamivudine

Pronunciation

(zye DOE vyoo deen & la MI vyoo deen)

U.S. Brand Names

Combivir®

Synonyms

AZT + 3TC; Lamivudine and Zidovudine

Generic Available

No

Canadian Brand Names

Combivir®

Use

Treatment of HIV infection when therapy is warranted based on clinical and/or immunological evidence of disease progression. Combivir® given twice daily, provides an alternative regimen to lamivudine 150 mg twice daily plus zidovudine 600 mg/day in divided doses; this drug form reduces capsule/tablet intake for these two drugs to 2 per day instead of up to 8.

Pregnancy Risk Factor

C

Pregnancy Implications

See individual agents.

Lactation

See individual agents.

Adverse Reactions

See individual agents.

Drug Interactions

Zidovudine: Substrate (minor) of CYP2A6, 2C8/9, 2C19, 3A4

Also see individual agents.

Mechanism of Action

The combination of zidovudine and lamivudine are believed to act synergistically to inhibit reverse transcriptase via DNA chain termination after incorporation of the nucleoside analogue as well as to delay the emergence of mutations conferring resistance

Pharmacodynamics/Kinetics

See individual agents.

Dosage

Children >12 years and Adults: Oral: One tablet twice daily

Note: Because this is a fixed-dose combination product, avoid use in patients requiring dosage reduction including children <12 years of age, renally impaired patients with a creatinine clearance 50 mL/minute, patients with low body weight (<50 kg or 110 pounds), or those experiencing dose-limiting adverse effects.

Patient Education

Combivir® is not a cure for HIV and you may continue to experience HIV-associated illness. Major toxicities are neutropenia and/or anemia; have blood counts checked regularly while on therapy. Pregnancy/breast-feeding precautions: Inform prescriber if you are or intend to become pregnant. Do not breast-feed.

Dental Health: Effects on Dental Treatment

No significant effects or complications reported

Dental Health: Vasoconstrictor/Local Anesthetic Precautions

No information available to require special precautions

Mental Health: Effects on Mental Status

Dizziness, insomnia, sedation are common; may cause depression. May rarely cause confusion or mania

Mental Health: Effects on Psychiatric Treatment

Leukopenia and granulocytopenia are common; caution with clozapine and carbamazepine. Increased toxicity may result if used concurrently with drugs that inhibit glucuronidation or excretion (lorazepam). Valproic acid increased zidovudine's AUC by 80% and decreased clearance by 38%.

Dosage Forms

Tablet: Zidovudine 300 mg and lamivudine 150 mg

References

"Public Health Service Task Force Recommendations for Use of Antiretroviral Drugs in Pregnant HIV-1-Infected Women for Maternal Health and Interventions to Reduce Perinatal HIV-1 Transmission in the United States," June 23, 2004. Available at: http://www.aidsinfo.nih.gov. Accessed July 1, 2004.

International Brand Names

Combivir® (CA)