Oseltamivir

Oseltamivir refers to antiviral agents that are active against influenza A and B viruses. Other trade names for the drug are Tamiflu, Floustop.

[1], [2], [3], [4], [5], [6], [7],

Indications Oseltamivir

The medication is prescribed for the treatment of patients infected with the influenza A and B virus, but can be used to prevent infection with this virus during seasonal influenza epidemics

[8], [9], [10], [11]

Release form

Capsules of 75 mg, powder for the preparation of a suspension in a vial (with a dispenser).

[12], [13], [14], [15], [16], [17]

Pharmacodynamics

The therapeutic effect of oseltamivir is based on inhibiting the activity of enzymes on the surface of the virion of the influenza virus. In the body, the active substance of the oseltamivir phosphate drug is transformed into an active metabolite - oseltamivir carboxylate, which selectively inhibits neurominidase-the glycosidase enzyme-antigen of the cell membranes of influenza viruses. As a result, the process of replication of viral cells and their multiplication in affected target cells of the mucous membrane of the respiratory tract ceases.

According to clinical studies, if the drug is taken within 36 hours after the onset of flu symptoms, the duration of the disease is reduced by almost 30%, and the severity of the symptoms and the likelihood of complications is reduced by 40%.

[18], [19], [20],

Pharmacokinetics

90% of oseltamivir phosphate, absorbed in the gastrointestinal tract, is metabolized into oseltamivir carboxylate, which enters the systemic circulation; 3% of the substance binds to blood plasma proteins. Biological availability is 75-80%.

The half-life of the drug from the plasma is on average 120 minutes. From the organism of oseltamivir, carboxylate is excreted by the kidneys (80%) and the intestine (20%); the half-life can be from 6 to 10 hours.

[21], [22], [23], [24], [25], [26]

Dosing and administration

Oseltamivir should be taken orally (regardless of meals). For the treatment of influenza it is recommended to take one capsule (75 mg) - twice a day; course of treatment - 5 days. The dosage of the suspension is similar. For the prevention of influenza take 75 mg once a day, the duration of the drug after contact with patients with influenza is 10 days (preventive effect of the drug lasts only during its use).

[32], [33], [34], [35]

Use Oseltamivir during pregnancy

The use of oseltamivir during pregnancy and during lactation is not recommended, since the safety of this drug for the treatment of pregnant women has not been investigated.

Contraindications

Contraindicated use of oseltamivir with weakened immunity, severe renal failure, chronic respiratory pathologies and cardiovascular system, as well as children under 12 years.

[27], [28]

Side effects Oseltamivir

The most common side effects of oseltamivir are manifested in the form of general weakness, headaches and dizziness; catarrhal phenomena (rhinorrhea, edema of the nasal mucosa, sore throat, cough); nausea, vomiting, diarrhea, abdominal pain; sleep disorders, seizures; allergic reactions (urticaria, spasm of bronchi, conjunctivitis); bleeding from the nose, cardiac arrhythmia, increased activity of hepatic enzymes. Possible hallucinations and mental disorders.

[29], [30], [31]

Overdose

Cases of overdose are not described. The most likely manifestation of excess of the therapeutic dose is an increase in the side effects of the drug. Symptomatic treatment should be used.

[36], [37]

Interactions with other drugs

The simultaneous administration of oseltamivir with such drugs as methotrexate, phenylbutazone and chlorpropamide is undesirable because of the possible delay in the excretion of their metabolites from the body.

[38], [39], [40], [41], [42]

Storage conditions

Keep out of reach of children, at temperatures up to + 25 ° C.

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Shelf life

Shelf life - 24 months.

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