Avilam150 mg

Avilam is a nucleoside reverse transcriptase inhibitor (NRTI) indicated, at this HIV-specific dose, for the treatment of HIV-1 infection in adults and pediatric patients.

• Established/approved use: Avilam is used as part of a combination antiretroviral therapy (ART) regimen with other antiretroviral agents (typically two other active drugs) for the treatment of HIV-1 infection. It must never be used as monotherapy or added as a single agent to a failing regimen.
• Guideline-supported use: Recommended by WHO and national ART guidelines as a component of first-line and alternative combination regimens for both treatment-naive and, in specific situations, treatment-experienced patients, guided by resistance testing where available.
• Not indicated for: Avilam at this HIV-treatment dose is not intended for chronic hepatitis B monotherapy; a separate, lower-dose lamivudine product is used for hepatitis B, and patients should not substitute between the two without physician guidance.

Use of Avilam must always be directed by a physician experienced in HIV management, with regular monitoring of viral load, CD4 count, and treatment adherence.

Each tablet/oral solution of Lamivudine [For HIV Infection] contains the active ingredient lamivudine at the HIV-indicated strength, formulated as follows (strengths vary by manufacturer and market presentation):

• Tablet: Lamivudine 150 mg or 300 mg
• Oral solution: Lamivudine 10 mg/mL

Lamivudine [For HIV Infection] also contains standard pharmaceutical excipients appropriate to the dosage form; patients with known excipient sensitivities should review the specific product's package insert.

Avilam is a synthetic nucleoside analogue with activity against the human immunodeficiency virus (HIV). It belongs to the class of nucleoside reverse transcriptase inhibitors (NRTIs), which form the backbone of most combination antiretroviral regimens.

Avilam is supplied as oral tablets and, for patients unable to swallow tablets (including young children), as an oral solution. It is well absorbed orally, is not significantly metabolized by hepatic cytochrome P450 enzymes, and is eliminated predominantly unchanged by the kidneys.

Avilam belongs to the therapeutic class of Antiretroviral agents, specifically the subclass Nucleoside Reverse Transcriptase Inhibitors (NRTIs).

Mechanism of Action

Lamivudine [For HIV Infection] is a nucleoside analogue that is phosphorylated intracellularly to its active 5'-triphosphate form (lamivudine triphosphate). This active metabolite competes with the natural nucleotide substrate (deoxycytidine triphosphate) for incorporation into viral DNA by HIV reverse transcriptase. Once incorporated, it causes premature chain termination because it lacks a 3'-hydroxyl group needed to extend the DNA chain, thereby halting viral replication.

Pharmacokinetics

• Absorption: Rapidly and well absorbed orally, with bioavailability of approximately 80–85% in adults; may be taken with or without food.
• Distribution: Widely distributed, with modest cerebrospinal fluid penetration.
• Metabolism: Minimally metabolized; not a substrate for hepatic CYP450 enzymes to a clinically significant degree.
• Elimination: Predominantly excreted unchanged in urine via active tubular secretion; plasma elimination half-life is approximately 5–7 hours in adults, while the intracellular half-life of the active triphosphate is considerably longer, supporting once- or twice-daily dosing.

• Avilam tablets may be swallowed whole, with or without food.
• The oral solution should be measured accurately using an appropriate oral dosing device (not a household spoon).
• Take Avilam at the same times each day to maintain consistent drug levels.
• Do not skip, delay, or double doses; if a dose is missed, take it as soon as remembered unless it is almost time for the next dose.
• Avilam must always be taken exactly as prescribed and in combination with the other antiretroviral medicines in the regimen; do not stop, interrupt, or take it alone without medical advice, as incomplete adherence promotes HIV drug resistance and treatment failure.

Avilam is not a significant substrate, inhibitor, or inducer of hepatic CYP450 enzymes, so clinically significant metabolic drug interactions are uncommon. However, the following interactions are clinically relevant:

• Trimethoprim/sulfamethoxazole (co-trimoxazole): Trimethoprim inhibits the renal tubular secretion of lamivudine, increasing lamivudine plasma concentrations; used together clinically (e.g., for opportunistic infection prophylaxis) but with awareness of increased exposure.
• Sorbitol-containing medicines: Concomitant chronic use of sorbitol-containing oral solutions can reduce lamivudine exposure; avoid chronic co-administration where possible.
• Other cytidine-analogue antivirals (e.g., emtricitabine): Avilam should not be combined with other lamivudine-like (cytidine analogue) antiretrovirals, as they share mechanism and resistance pathways without added benefit and with additive toxicity risk.
• Interferon alfa and ribavirin (in HBV/HCV co-infected patients): Increased risk of hepatic decompensation has been reported when nucleoside analogues are combined with interferon-based regimens; monitor closely.

Always inform the prescribing physician of all other medicines, supplements, and herbal products being used before starting Avilam.

Common side effects

• Headache
• Nausea, vomiting, diarrhea, abdominal discomfort
• Fatigue and malaise
• Nasal symptoms, cough
• Insomnia and other sleep disturbances
• Musculoskeletal pain, arthralgia

Serious side effects

• Lactic acidosis and severe hepatomegaly with steatosis (a class warning for NRTIs), which can be life-threatening; symptoms include unusual fatigue, abdominal pain, nausea, and difficulty breathing — seek immediate medical attention if these occur.
• Severe acute exacerbation of hepatitis B in patients co-infected with hepatitis B virus (HBV) who discontinue Avilam; close clinical and laboratory monitoring is required for several months after stopping.
• Pancreatitis, reported more frequently in pediatric patients with advanced HIV disease or prior extensive nucleoside exposure.
• Immune reconstitution inflammatory syndrome (IRIS) — an inflammatory response to previously subclinical infections that may occur after starting combination ART including Avilam.
• Redistribution/accumulation of body fat (lipodystrophy) with long-term antiretroviral therapy.

Pregnancy: Combination antiretroviral therapy, including regimens containing Avilam, is generally recommended during pregnancy in women living with HIV to treat maternal infection and reduce the risk of perinatal (mother-to-child) HIV transmission, per current guideline-directed care. Avilam should be used in pregnancy only under the direction of a physician, who will weigh the benefits against any potential risks and select an appropriate regimen; do not start or stop antiretroviral therapy during pregnancy without medical advice.

Lactation: Lamivudine is excreted into breast milk. Infant feeding decisions for mothers living with HIV should be individualized based on maternal viral suppression, local guidelines, and physician advice, as breastfeeding carries a risk of postnatal HIV transmission. Consult the treating physician before breastfeeding while taking Avilam.

• Lactic acidosis/hepatomegaly with steatosis: A class warning for NRTIs including Avilam; discontinue promptly if clinical or laboratory findings suggestive of this condition develop.
• Hepatitis B co-infection: Patients co-infected with HBV who discontinue Avilam may experience severe hepatitis exacerbation; hepatic function should be monitored closely for several months after stopping therapy, with re-institution of anti-HBV therapy considered if warranted.
• Pancreatitis: Discontinue promptly if clinical signs, symptoms, or laboratory abnormalities suggestive of pancreatitis develop, particularly in pediatric patients.
• Immune reconstitution inflammatory syndrome: Monitor for inflammatory symptoms of previously subclinical opportunistic infections after starting therapy.
• Adherence and resistance: Avilam must be taken exactly as prescribed, as part of the complete combination regimen, without stopping, skipping doses, altering the dose, or sharing this medicine with others without medical advice — incomplete adherence promotes selection of drug-resistant HIV strains and treatment failure.
• Renal impairment: Dose adjustment is required; use with caution and appropriate monitoring in patients with reduced renal function.

Limited data exist on acute overdose with Avilam. No specific antidote is known. In the event of a suspected overdose, seek immediate medical attention or contact a poison control center. Management is supportive and symptomatic; general measures such as monitoring of vital signs and, if clinically appropriate as advised by a physician, hemodialysis may be considered given lamivudine's renal elimination, though its efficacy for overdose is not established. Do not attempt to manage a suspected overdose at home without medical guidance.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

• Renal impairment: Avilam is eliminated primarily by the kidneys; dose or dosing-interval reduction is required based on creatinine clearance. Close monitoring is advised.
• Hepatic impairment: No dose adjustment is generally required based on hepatic function alone, as lamivudine is minimally hepatically metabolized; however, caution is warranted in patients with hepatitis B co-infection and decompensated liver disease (see Precautions).
• Elderly: Limited specific data are available; age-related decline in renal function should be considered, and renal monitoring is advised.
• Pediatric patients: Approved for use from 3 months of age using weight-based dosing (see Pediatric Uses).
• Pregnancy and lactation: See Pregnancy and Lactation section.

Avilam is intended for long-term, typically lifelong, use as part of a continuous combination antiretroviral regimen for the management of chronic HIV-1 infection. Duration and regimen composition should be determined and periodically reviewed by the treating physician based on virologic response, immune status, tolerability, and resistance testing. Avilam should not be discontinued or interrupted without medical supervision, particularly in patients co-infected with hepatitis B, due to the risk of hepatitis exacerbation and the development of HIV drug resistance.

Antiretroviral agents; Nucleoside Reverse Transcriptase Inhibitors (NRTIs)

Lamivudine [For HIV Infection] (lamivudine) is intracellularly phosphorylated by cellular kinases to lamivudine triphosphate, its pharmacologically active form. This metabolite acts as a competitive inhibitor of HIV-1 reverse transcriptase, competing with the natural substrate deoxycytidine triphosphate (dCTP) for incorporation into the growing proviral DNA chain. Because lamivudine triphosphate lacks a 3'-hydroxyl group, its incorporation results in obligate chain termination, preventing further elongation of viral DNA and halting HIV replication.

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Avilam is approved for the treatment of HIV-1 infection in pediatric patients from 3 months of age, always as part of a combination antiretroviral regimen appropriate for the child's age and weight.

• Dosing is weight-based, typically using the oral solution (10 mg/mL) in infants and young children, transitioning to tablets as the child grows and can swallow them reliably.
• Safety and efficacy in infants younger than 3 months have not been established.
• Pediatric patients with advanced HIV disease, particularly those with a history of prior nucleoside exposure, appear to be at increased risk of pancreatitis and should be monitored closely for symptoms such as abdominal pain, nausea, and vomiting.
• Growth, adherence, and virologic and immunologic response should be monitored regularly by a pediatric HIV specialist.