Lamivudine-Zidovudine 150mg-300mg

Lamivudine-Zidovudine 150mg-300mg – Quick Overview

Lamivudine-Zidovudine 150mg-300mg (formerly branded Combivir®) is a fixed-dose combination tablet used with other antiretroviral medicines to treat HIV-1 infection in adults and adolescents weighing at least 30 kg. It combines two nucleoside reverse transcriptase inhibitors that work together to slow HIV replication. This medicine is prescription-only and carries an FDA boxed warning for serious blood and liver-related toxicity.

Medical Supervision & Regulatory Status

Lamivudine-Zidovudine 150mg-300mg is FDA-approved and available only by prescription in the United States, though the Combivir brand name has been discontinued in the U.S., with generic equivalents available where approved by the FDA. It carries an FDA boxed warningcovering hematologic toxicity, symptomatic myopathy, lactic acidosis and severe hepatomegaly, and severe acute exacerbations of hepatitis B, so close medical supervision is required.

Clinical Context

HIV-1 infection progressively weakens the immune system by attacking CD4 cells, and if left untreated, it can lead to opportunistic infections and advanced immunodeficiency (AIDS). Long-term, consistent antiretroviral therapy is essential to suppress viral replication and preserve immune function.

Combining two nucleoside reverse transcriptase inhibitors is a foundational treatment strategy in HIV therapy, forming the “backbone” of most combination regimens, because it attacks the virus at the same enzymatic step through complementary mechanisms, reducing the risk of resistance compared to a single agent.

Lamivudine-zidovudine fits into therapy as part of a broader antiretroviral regimen — it is not used alone but combined with a third antiretroviral agent from a different drug class, as directed by a physician based on resistance testing and treatment history.

How Lamivudine-Zidovudine Works

Both lamivudine and zidovudine belong to the nucleoside reverse transcriptase inhibitor (NRTI) class of antiretroviral medicines.

In simple terms, both drugs work by mimicking the natural building blocks HIV needs to copy its genetic material; once incorporated into the growing viral DNA chain by the reverse transcriptase enzyme, they cause the chain to terminate prematurely, halting viral replication.

By combining two NRTIs with complementary resistance profiles, this fixed-dose tablet helps suppress HIV replication more effectively as part of a complete antiretroviral regimen, supporting long-term immune system preservation.

What is Lamivudine-Zidovudine 150mg-300mg?

• Drug Class: Nucleoside reverse transcriptase inhibitor (NRTI) combination
• Active Ingredients: Lamivudine 150 mg, Zidovudine 300 mg
• Mechanism: Both components terminate viral DNA chain synthesis by HIV reverse transcriptase, blocking viral replication
• Form: Oral tablet
• Dosing Frequency: One tablet taken orally twice daily
• Regulatory Status: FDA-approved, prescription-only (Rx)

Uses / Indications

• HIV-1 infection, combination therapy: Used in HIV-1-infected adults and adolescents weighing 30 kg or more, in combination with other antiretroviral agents, to suppress viral replication.

This is a fixed-dose tablet and cannot be dose-adjusted, so it is not suitable for patients requiring individualized dosing of either component.

How to Use / Dosage

The typical dosage is one tablet, containing 150 mg lamivudine and 300 mg zidovudine, taken orally twice daily, as part of a complete antiretroviral regimen prescribed by a physician. Because the components cannot be separated or adjusted, this tablet requires reliable ability to swallow tablets; liquid formulations of the individual components are available for those who cannot. If a dose is missed, take it as soon as remembered, unless it is close to the next scheduled dose — do not double up. Do not stop this medication without consulting your doctor, as interruptions can affect viral suppression and increase resistance risk; if you also have hepatitis B, stopping suddenly can cause a serious flare of liver disease.

Side Effects

Most people tolerate this combination with some side effects that should be discussed with a doctor. Common effects may include headache, nausea, fatigue, and mild gastrointestinal upset. Serious effects, though less common, may include hematologic toxicity such as neutropenia and anemia, symptomatic myopathy with prolonged use, and lactic acidosis with hepatomegaly and steatosis, including fatal cases.

Emergency Warning Signs — Seek immediate medical care if you experience:

• Unusual tiredness, muscle weakness, or shortness of breath (possible lactic acidosis)
• Signs of severe anemia (pale skin, rapid heartbeat, extreme fatigue)
• Unusual bruising or bleeding, or signs of infection (fever, chills)
• Muscle pain, tenderness, or weakness
• Yellowing of the skin or eyes (jaundice)
• Severe abdominal pain, nausea, or vomiting
• Worsening liver symptoms, especially if you also have hepatitis B and stop this medicine

Warnings & Precautions

This combination carries an FDA boxed warning for hematologic toxicity, myopathy, lactic acidosis, and severe hepatomegaly with steatosis, as well as severe hepatitis B flares after discontinuation. It is contraindicated in patients with a previous hypersensitivity reaction to lamivudine or zidovudine and should not be administered with other lamivudine- or zidovudine-containing products, or emtricitabine-containing products. Drug interactions are significant: co-administration of ribavirin and zidovudine is not advised due to worsened anemia risk in HIV/HCV co-infected patients, and combination therapy with interferon alfa with or without ribavirin has been linked to hepatic decompensation. Because this is a fixed-dose tablet, it is not recommended for patients requiring dosage adjustment, or those with hepatic impairment or experiencing dose-limiting adverse reactions; dose reduction of both components is recommended for patients with impaired kidney function. Use during pregnancy and breastfeeding should be discussed with a physician, as breastfeeding is not recommended for mothers with HIV due to transmission risk. Female sex and obesity may be risk factors for lactic acidosis and severe hepatomegaly with steatosis. Frequent blood counts are strongly recommended in patients with advanced HIV-1 disease, and periodic blood counts are recommended for other HIV-1-infected patients throughout therapy.

Who Should Not Use This Medication

• People with a known hypersensitivity reaction to lamivudine or zidovudine
• Individuals already taking another lamivudine-, zidovudine-, or emtricitabine-containing product
• Patients with impaired hepatic function, given the inability to adjust this fixed-dose tablet
• Anyone requiring individualized dosing of either component
• Patients under 30 kg body weight who cannot use the fixed adult dose

Storage Instructions

Store Lamivudine-Zidovudine 150mg-300mg tablets at room temperature, away from excess heat and moisture. Keep the container tightly closed and protect from direct light. Keep out of reach of children and pets, and dispose of unused or expired medication appropriately rather than in household trash.

Frequently Asked Questions

What is the cost of Lamivudine-Zidovudine 150mg-300mg without insurance?

The cost without insurance depends on the seller, brand availability, and pack size, and may also vary by location and available discounts. Generic versions are often more affordable than the discontinued brand product.

How can I order Lamivudine-Zidovudine 150mg-300mg online?

A valid prescription is required to order this medication. Typically, you upload a prescription or have your doctor send it directly, then order from a licensed pharmacy for home delivery. Always verify the pharmacy is properly licensed before ordering.

Is Lamivudine-Zidovudine 150mg-300mg available over the counter?

No, it is not available over the counter in the United States or most other countries. Regulations may vary by region, but medical supervision is required due to its serious safety warnings.

Does Lamivudine-Zidovudine 150mg-300mg require a prescription? Yes, a prescription is required. This ensures proper evaluation of kidney and liver function before starting, along with ongoing monitoring for safety.

How long does it take to work?

Viral suppression typically develops over several weeks to months of consistent use as part of a full antiretroviral regimen, with viral load testing used to monitor treatment response over time.

Can I stop taking this medication suddenly?

No, stopping suddenly without medical advice can lead to loss of viral suppression, increased resistance risk, and, in patients with hepatitis B, a serious flare of liver disease.

Does this medication interact with other drugs?

Yes, it can interact with ribavirin, interferon alfa, and other lamivudine- or zidovudine-containing products. Always tell your doctor about all medications and supplements you take before starting therapy.

Resources

• MedlinePlus – Lamivudine and Zidovudine: https://medlineplus.gov/druginfo/meds/a696011.html
• FDA – Lamivudine and Zidovudine Tablets Prescribing Information: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/022018Lbl.pdf
• DailyMed (NIH) – COMBIVIR Lamivudine and Zidovudine Tablet Label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=479a2784-8db2-4fe5-94ba-55316a3c4e4f

References:

1. FDA – Lamivudine and Zidovudine Tablets Full Prescribing Information, including Boxed Warning: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/022018Lbl.pdf
2. DailyMed (NIH) – COMBIVIR (lamivudine and zidovudine) Tablet Label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=479a2784-8db2-4fe5-94ba-55316a3c4e4f
3. MedlinePlus – Lamivudine and Zidovudine: https://medlineplus.gov/druginfo/meds/a696011.html

Medical Disclaimer:

This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Consult a qualified specialist or physician before using Lamivudine-Zidovudine.