Olsivir Capsule contains Oseltamivir Phosphate 75 mg, an antiviral agent indicated for the treatment and prevention of influenza A and B infections. Oseltamivir is a neuraminidase inhibitor that impedes the release of progeny influenza virus from infected host cells, thereby limiting viral spread within the respiratory tract. It is most effective when administered within 48 hours of symptom onset, reducing the duration and severity of influenza symptoms such as fever, cough, sore throat, and body aches. Olsivir Capsule is also used prophylactically to reduce the incidence of influenza in individuals exposed to the virus. The recommended dosage varies depending on patient age, weight, and clinical condition; adults typically receive 75 mg twice daily for five days during treatment, while prophylactic dosing is usually 75 mg once daily for up to 10 days. Oseltamivir is generally well tolerated, with common adverse effects including nausea, vomiting, and abdominal discomfort, which are usually transient. Caution is advised in patients with renal impairment, and dose adjustments may be necessary. Olsivir Capsule should be used under medical supervision, especially in pregnant or breastfeeding women, and is not a substitute for annual influenza vaccination.