PANVIRIN 400mg Capsules (Hard Gelatin)

What is PANVIRIN 400mg

PANVIRIN 400mg Capsules contain Ribavirin, an antiviral medication primarily used in the treatment of chronic Hepatitis C infection, often in combination with other antiviral agents like interferons or direct-acting antivirals (DAAs). Ribavirin is a synthetic nucleoside analogue with a broad spectrum of activity against several RNA and DNA viruses.

• Generic Name: Ribavirin
• Formulation: Hard Gelatin Capsules
• Strength: 400mg per capsule
• Packaging: 100 capsules per pack (10s blister x 10)
• Class: Antiviral agent
• Primary Indication: Chronic Hepatitis C (in combination therapy)

Ribavirin is not effective when used alone and should always be prescribed as part of a combination regimen tailored to the patient's specific genotype, viral load, and liver status.

How to use PANVIRIN 400mg

Correct administration of PANVIRIN 400mg ensures therapeutic efficacy and minimizes adverse effects. Always use this medication under the supervision of a healthcare professional.

• Swallow the capsule whole with a glass of water; do not crush, chew, or open the capsule.
• Take the medication with food to enhance absorption and reduce gastrointestinal side effects.
• Typically administered twice daily (morning and evening), depending on the total daily dose prescribed.
• Duration of therapy can range from 12 to 48 weeks based on the treatment protocol and viral genotype.
• Ensure adherence to the full treatment regimen to prevent viral resistance and relapse.
• If a dose is missed, take it as soon as remembered, unless it’s close to the next scheduled dose—do not double up doses.
• Regular monitoring (CBC, liver enzymes, hemoglobin levels) is necessary throughout the treatment period.

Patients must be counseled on the importance of birth control during and after therapy, as Ribavirin is teratogenic and contraindicated in pregnancy.

Mode of Action PANVIRIN 400mg

Ribavirin exerts its antiviral effects through multiple complex mechanisms, targeting viral replication and host immune response.

• Inhibition of Viral RNA Synthesis: Ribavirin mimics naturally occurring nucleosides, interfering with the synthesis of viral RNA by inhibiting RNA-dependent RNA polymerase.
• Lethal Mutagenesis: Incorporates into viral RNA leading to accumulation of mutations, rendering the virus nonviable (error catastrophe).
• Immunomodulatory Effects: Enhances T-helper cell type 1 (Th1) responses, aiding the immune system in clearing the virus.
• Inhibition of Inosine Monophosphate Dehydrogenase: Depletes intracellular guanosine triphosphate (GTP) pools, crucial for viral genome replication.

This multifaceted action makes Ribavirin effective against a variety of RNA viruses, particularly Hepatitis C when used in combination therapy. However, its effectiveness alone is minimal, hence it is never used as monotherapy.

PANVIRIN 400mg Interactions PANVIRIN 400mg

Ribavirin can interact with a range of medications, potentially altering therapeutic efficacy or increasing toxicity. It's crucial to inform your healthcare provider of all medications and supplements you are taking.

• Antiretroviral Drugs (e.g., Zidovudine, Didanosine): Ribavirin may increase the risk of mitochondrial toxicity, pancreatitis, or lactic acidosis.
• Interferon Alfa: Synergistic effect when used in combination for Hepatitis C, but may enhance hematologic toxicity.
• Azathioprine: Co-administration may increase the risk of myelotoxicity due to inhibition of purine metabolism.
• Warfarin: Close monitoring of INR is needed as Ribavirin may alter anticoagulant effect.
• HIV Medications: Caution is needed due to increased toxicity or interactions in HIV-HCV co-infected patients.

Patients are advised to avoid alcohol and non-essential medications unless approved by their healthcare provider. Monitoring of blood counts and liver function should be conducted regularly during therapy.

Dosage of PANVIRIN 400mg

The dose of Ribavirin is weight-based and individualized according to the patient's body weight, liver function, and concomitant medications. The following outlines standard dosage protocols:

• Body Weight ≤ 75 kg: Total daily dose = 1000 mg (400 mg AM + 600 mg PM)
• Body Weight > 75 kg: Total daily dose = 1200 mg (600 mg AM + 600 mg PM)
• Frequency: Usually taken twice daily with meals
• Duration: Ranges from 12 to 48 weeks depending on the viral genotype and combination regimen

In cases of renal impairment or anemia, dosage adjustments are essential:

• CrCl < 50 mL/min: Dose should be reduced or Ribavirin discontinued
• Hemoglobin < 10 g/dL: Consider dose reduction to 600 mg/day

Always follow your healthcare provider's instructions and avoid self-modifying the dose or treatment duration.

Possible side effects of PANVIRIN 400mg

Like all medications, PANVIRIN (Ribavirin) can cause side effects, ranging from mild to serious. Regular monitoring and communication with a healthcare provider are essential during treatment.

• Very Common:
  • Fatigue, headache, nausea
  • Anemia (hemolytic)
  • Irritability or mood changes
• Common:
  • Cough, dyspnea
  • Insomnia
  • Muscle or joint pain
  • Pruritus or rash
• Serious:
  • Severe hemolytic anemia
  • Suicidal thoughts or depression
  • Pancreatitis
  • Hepatic decompensation
  • Cardiac arrhythmias (especially in patients with preexisting heart disease)

Seek immediate medical attention for signs of allergic reaction, chest pain, or significant changes in mood or behavior.

PANVIRIN 400mg Contraindications PANVIRIN 400mg

PANVIRIN is contraindicated in certain individuals due to its serious adverse effect profile. Use should be avoided in the following cases:

• Pregnancy: Ribavirin is highly teratogenic and contraindicated in pregnant women or those planning pregnancy.
• Male partners of pregnant women: Must not take Ribavirin unless effective contraception is used.
• Severe Renal Impairment (CrCl < 50 mL/min): Due to accumulation and increased toxicity risk.
• Autoimmune Hepatitis: Ribavirin may exacerbate immune-related liver injury.
• Uncontrolled Psychiatric Disorders: Risk of exacerbation including suicidal ideation.
• Hemoglobinopathies (e.g., Thalassemia, Sickle Cell Anemia): Risk of severe hemolytic anemia.

Ribavirin is also contraindicated in patients with known hypersensitivity to the drug or any component of the capsule formulation.

Storage of PANVIRIN 400mg

Proper storage of PANVIRIN 400mg is important to maintain its stability and therapeutic efficacy.

• Temperature: Store at room temperature between 15°C to 30°C (59°F to 86°F)
• Humidity: Protect from excessive moisture and humidity
• Light: Keep the capsules in their original blister packaging to protect from light exposure
• Child Safety: Store out of reach and sight of children
• Do Not Freeze: Freezing can compromise capsule integrity
• Disposal: Do not dispose of via household waste or wastewater. Return unused medication to a pharmacy collection site when possible.

Always check the expiration date before use and consult your pharmacist regarding proper disposal methods if the medication is no longer needed.