Combivir is a fixed-dose combination antiretroviral medication containing lamivudine and zidovudine, designed for the treatment of human immunodeficiency virus (HIV-1) infection in adults and children. As a cornerstone of highly active antiretroviral therapy (HAART), it works by inhibiting reverse transcriptase, thereby reducing viral replication and slowing disease progression. This combination offers simplified dosing and enhanced adherence support, making it a reliable option for long-term management of HIV. Clinical evidence supports its role in maintaining undetectable viral loads and improving immune reconstitution when used as part of a comprehensive treatment regimen.

Features

• Contains 150 mg lamivudine and 300 mg zidovudine per tablet
• Fixed-dose combination for simplified regimen management
• Bioequivalent to individual components administered separately
• Film-coated tablet for ease of swallowing
• Manufactured under strict quality control standards
• Suitable for use in pediatric patients weighing at least 30 kg

Benefits

• Provides dual nucleoside reverse transcriptase inhibitor (NRTI) activity in a single tablet
• Reduces pill burden and supports treatment adherence
• Demonstrates proven efficacy in suppressing HIV viral load
• Helps maintain or increase CD4 cell counts
• May delay disease progression to AIDS-defining conditions
• Supported by extensive clinical trial data and real-world evidence

Common use

Combivir is indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents. It is typically prescribed as part of a three-drug regimen for both treatment-naïve patients and those switching from individual component therapy. The medication is used across diverse patient populations, including appropriate pediatric patients, and may be incorporated into various treatment strategies based on resistance testing and treatment history.

Dosage and direction

The recommended adult dosage is one tablet taken orally twice daily, with or without food. For pediatric patients weighing 30 kg or more, the same adult dosage applies. Tablets should be swallowed whole with water and not chewed, crushed, or split. Dosage adjustment may be necessary in patients with renal impairment (creatinine clearance <50 mL/min). Treatment should be initiated and monitored by healthcare providers experienced in HIV management.

Precautions

• Monitor complete blood counts regularly due to risk of hematologic toxicity
• Assess liver function before and during treatment
• Evaluate patients for hepatitis B coinfection before initiation
• Monitor for clinical signs of pancreatitis, especially in pediatric patients
• Assess for symptoms of myopathy and peripheral neuropathy
• Regular monitoring of blood lactate levels recommended
• Pregnancy testing recommended before initiation in women of childbearing potential
• Consider potential for lipoatrophy with long-term use

Contraindications

• Hypersensitivity to lamivudine, zidovudine, or any component of the formulation
• Life-threatening allergic reactions to any of the components
• Use with other medications containing lamivudine or zidovudine
• Patients with significantly reduced bone marrow reserve evidenced by granulocyte count <1000 cells/mm³ or hemoglobin <9.5 g/dL
• Combination with stavudine due to antagonistic effects

Possible side effects

Common (≥10%):

• Headache
• Nausea
• Fatigue
• Malaise
• Nasal signs and symptoms
• Diarrhea
• Cough
• Rash

Less common (1-10%):

• Anemia
• Neutropenia
• Insomnia
• Dizziness
• Fever
• Myalgia
• Arthralgia
• Elevated liver enzymes

Rare (<1%):

• Lactic acidosis
• Severe hepatomegaly with steatosis
• Pancreatitis
• Peripheral neuropathy
• Myopathy
• Hepatic failure
• Stevens-Johnson syndrome

Drug interaction

• Ganciclovir/valganciclovir: Increased risk of hematologic toxicity
• Ribavirin: Antagonistic effect with zidovudine; avoid concomitant use
• Stavudine: Pharmacologic antagonism; contraindicated
• Doxorubicin: May enhance myelosuppressive effects
• Interferon alfa: Increased risk of hepatic decompensation and neutropenia
• Nephrotoxic agents: May reduce clearance of lamivudine
• Probenecid: May increase zidovudine exposure
• Trimethoprim/sulfamethoxazole: Increases lamivudine concentration

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next scheduled dose. Do not double the dose to make up for a missed dose. Maintain regular dosing schedule to ensure consistent drug levels. If multiple doses are missed, contact healthcare provider for guidance on resuming therapy.

Overdose

Symptoms may include nausea, vomiting, lethargy, and hematologic toxicity. Hemodialysis may enhance elimination of lamivudine but has limited effect on zidovudine removal. Management should include supportive care with monitoring of hematologic parameters and treatment of specific symptoms. There is no specific antidote; treatment should be directed at supporting vital functions and managing complications.

Storage

Store at 20-25°C (68-77°F); excursions permitted to 15-30°C (59-86°F). Keep in original container with tight closure. Protect from moisture and light. Keep out of reach of children. Do not use if packaging is damaged or tablets show signs of deterioration. Properly dispose of unused or expired medication according to local regulations.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Treatment decisions should be made in consultation with qualified healthcare professionals. The prescribing physician should be familiar with the complete prescribing information and current treatment guidelines. Individual patient response may vary, and appropriate monitoring is essential throughout treatment.

Reviews

Clinical studies demonstrate Combivir’s efficacy in maintaining viral suppression with 60-80% of patients achieving undetectable viral loads (<50 copies/mL) at 48 weeks when combined with a third agent. Real-world evidence supports sustained virologic response rates comparable to other NRTI backbones. Patients report high satisfaction with the reduced pill burden, though some note gastrointestinal side effects during initial treatment phases. Healthcare providers appreciate the established safety profile and convenience of the fixed-dose combination in appropriate patient populations.