Oseltamivir 75 mg Capsules – Powerful Antiviral for Influenza Treatment & Prevention

What is Oseltamivir 75 mg?

Oseltamivir 75 mg is an oral antiviral medication primarily used for the treatment and prevention of influenza A and B viruses. Marketed under various brand names including Tamiflu, it belongs to the neuraminidase inhibitor class of drugs, which work by stopping the flu virus from spreading in the body. It is especially effective when administered within the first 48 hours of flu symptoms.

Composition

• Active Ingredient: Oseltamivir Phosphate equivalent to Oseltamivir 75 mg
• Form: Hard gelatin capsule
• Color: Usually yellow or light-colored (varies by brand)

Mechanism of Action

Oseltamivir inhibits the action of neuraminidase, an enzyme that allows the influenza virus to replicate and spread between cells. By blocking this enzyme, the drug:

• Reduces viral spread
• Lessens the severity and duration of symptoms
• Helps prevent complications like bronchitis or pneumonia

Indications

1. Treatment of Influenza
   1. For patients aged 2 weeks and older with acute, uncomplicated flu symptoms
   1. Most effective when started within 48 hours of symptom onset
2. Prevention (Prophylaxis) of Influenza
   1. For people exposed to the virus (e.g., family members, healthcare workers)
   1. Recommended for high-risk groups: elderly, immunocompromised, unvaccinated

Dosage & Administration

Treatment of Influenza

• Adults & Adolescents (13 years and older):
  → 75 mg twice daily for 5 days
• Children (1 to 12 years):
  → Dose adjusted by weight (consult pediatric dosing guide)
• Infants (2 weeks to <1 year):
  → 3 mg/kg twice daily for 5 days (as prescribed)

Prevention of Influenza

• Adults & Adolescents:
  → 75 mg once daily for at least 10 days after exposure
• Children:
  → Dose adjusted by weight and duration based on risk level

Note: Capsules can be taken with or without food. Taking with food may reduce the chance of stomach upset.

Benefits

• Shortens flu duration by 1–2 days when started early
• Reduces severity of symptoms such as fever, chills, sore throat, cough, and body aches
• Helps prevent serious flu-related complications
• Effective as a preventive measure during community outbreaks or close contact with infected individuals

Side Effects

Common (usually mild and temporary):

• Nausea
• Vomiting
• Headache
• Abdominal pain
• Fatigue

Less Common but Serious:

• Allergic reactions (rash, swelling, difficulty breathing)
• Neuropsychiatric events (hallucinations, confusion, delirium—more common in children)
• Skin reactions like Stevens-Johnson Syndrome (rare)

Warnings & Precautions

• Should not be used for illnesses caused by viruses other than influenza
• Start treatment within 48 hours of flu symptom onset for best effectiveness
• Use with caution in patients with:
  • Kidney impairment (dose adjustment may be needed)
  • Heart conditions
  • Liver disease
• Not a substitute for seasonal flu vaccination
• Safety in long-term use (more than 6 weeks) is not established

Drug Interactions

Oseltamivir has a low potential for significant drug interactions, but it’s important to inform your doctor if you’re taking:

• Live attenuated influenza vaccine (avoid within 2 weeks before or 48 hours after taking oseltamivir)
• Probenecid (may increase oseltamivir levels)
• Other antivirals or medications that affect kidney function

Use in Specific Populations

• Pregnancy: Category C – use only if clearly needed and prescribed
• Lactation: Small amounts may pass into breast milk; consult a doctor
• Children: Safe when used with age-appropriate dosing
• Elderly: No dosage adjustment needed unless kidney function is impaired

Storage Instructions

• Store at room temperature between 15°C and 25°C (59°F to 77°F)
• Keep in a dry place away from moisture and direct sunlight
• Keep out of reach of children