Proxivir 300

Indications

Proxivir, in conjunction with other antiretroviral agents, is prescribed for the treatment of HIV-1 infection. It is also indicated for the management of chronic hepatitis B in adults.

Pharmacology

Mechanism of Action: Tenofovir, the active ingredient in Proxivir, inhibits HIV reverse transcriptase by competing with the natural substrate, deoxyadenosine 5-triphosphate. This interference prevents the synthesis of viral DNA, crucial for viral replication.

Pharmacokinetics: Tenofovir is administered as a water-soluble diester prodrug. When taken orally, it reaches peak serum concentrations within 1.0 to 10.4 hours. It exhibits low protein binding (<0.7% to plasma proteins, <7.2% to serum proteins) and has an elimination half-life of approximately 17 hours. Tenofovir is excreted via renal filtration and active tubular secretion.

Dosage & Administration

For adults, the recommended dose of Tenofovir disoproxil is one 245 mg tablet orally once daily, irrespective of food intake. Pediatric patients aged 12 years and older, weighing at least 35 kg, should also take one 245 mg tablet daily.

Interactions

Proxivir may interact with medications like didanosine, atazanavir, and lopinavir/ritonavir, necessitating close monitoring for potential adverse reactions.

Contraindications

Proxivir is contraindicated in individuals with severe liver or kidney disease, acute hepatitis, and certain metabolic conditions.

Side Effects

Common side effects include headache, diarrhea, and nausea. Patients should promptly report serious side effects such as kidney problems or mood changes.

Pregnancy & Lactation

Tenofovir use during pregnancy is categorized as class B, indicating caution is advised. Breastfeeding is not recommended due to the risk of transmitting HIV-1 to infants.

Precautions & Warnings

Patients should be monitored for potential complications like lactic acidosis and liver enlargement. Renal function should be assessed regularly due to the drug’s renal elimination.

Use in Special Populations

Dosage adjustments are necessary for patients with renal impairment based on their creatinine clearance levels.

Storage Conditions

Store Proxivir tablets below 25°C in a dry place protected from light, and ensure they are out of reach of children.