"Oseltamivir": instructions for use, analogues, description of the preparation

What is the prescription for Oseltamivir? Instructions for use, analogs, indications and contraindications for this medication will be described below. Also, we will tell you about the form in which you can buy this medication, what properties it possesses, whether it has side effects, etc.

Form, composition, description of the medicinal product

In the sale of this drug comes in the form of white and yellow capsules. Oseltamivir is a pro-drug. When ingested, it undergoes hydrolysis and is converted to the active substance - oseltamivir carboxylate.

In addition to capsules, this medication is also available as a light powder for the preparation of an oral suspension.

Features of the drug

How does Oseltamivir work? The instruction for use states that the therapeutic effect of this drug is based on inhibiting the activity of enzymes that are located on the surface of the virion of the influenza virus.

After the receipt of the drug in the human body, its main component is transformed into an active metabolite. Thus, oseltamivir carboxylate selectively inhibits neurominidase. As a result of this influence, the process of multiplication of viral cells ceases.

According to specialists, this medication should be taken within 35 hours after the appearance of the first signs of influenza. Only so the duration of the disease can be reduced by 30%, and the likelihood of complications and the severity of the symptoms - by 40%.

Pharmacokinetics of the drug

Is the drug "Oseltamivir" absorbed? The instructions for use indicate that about 90% of oseltamivir phosphate is absorbed in the gastrointestinal tract. The active substance is converted to oseltamivir carboxylate, and then enters the systemic circulation.

About 3% of the active ingredient binds to plasma proteins. Its bioavailability is approximately 76-85%, and the half-life is 120 minutes.

From the human body, oseltamivir carboxylate is excreted by the kidneys (about 80%) and the intestines (20%). The half-life of this drug is 6-10 hours.

Indications for use

What is the purpose of Oseltamivir (pharmaceutical group - antiviral agents)? According to the attached instructions, this medication is used to treat influenza A and B. It is also often used to prevent these viral diseases.

Contraindications for use

Does Oseltamivir have contraindications (the description of the drug was presented above)? According to the instruction, this medicine is forbidden to take at:

• Hypersensitivity to the active component;
• Renal failure (safety and efficacy of the drug in this category of patients have not been determined);
• In childhood to 1 year (there is uncertainty regarding the formation of BBB in children);
• Pregnancy and breastfeeding (it is not known whether the drug is excreted into the breast milk of women, and whether it affects the fetus).

It should also be noted that this medication is not recommended for children under 13 years of age, since the experts did not determine the safety and effectiveness of Oseltamivir for the prevention and treatment of influenza.

Oseltamivir preparation: instructions for use

Vidal (the reference book of medicines) contains in itself the complete information on how and in what dosages it is necessary to take the given preparation. However, it should be noted that only the attending physician should prescribe this medication. After all, only an experienced specialist will be able to select the right treatment regimen that will quickly and effectively eliminate all unpleasant symptoms of a viral disease.

So in what dosage is Oseltamivir prescribed? Instructions for use indicate that this drug should be used no later than 2 days after the first signs of influenza.

Children over 13 years and adults are prescribed medication in an amount of 75 mg twice a day for 5 days. It should immediately be noted that increasing the dosage of the drug (eg, up to 150 mg per day) does not lead to an increase in the therapeutic effect.

If the drug should be prescribed to children aged 1-12 years, the dosage is selected depending on the weight of the child.

To prevent influenza, adults and children over 13 years of age are prescribed 75 mg 1 once a day for 6 weeks (for example, during an epidemic).

In patients with Cl creatinine less than 30 ml per minute, dosage adjustment is required (75 mg once daily for 5 days).

Side effects after taking medication

What adverse reactions occur after taking Oseltamivir? Instructions for use say that the most often manifested undesirable reactions are nausea and vomiting. In most cases, such effects are mild or moderate and usually occur during the first days of treatment.

It should also be noted that in some patients, bronchitis, vertigo, insomnia, unstable angina, pseudomembranous colitis, anemia, pneumonia, fracture of the humerus, peritonsillar abscess and fever develop in some patients.

Very rarely, people taking Oseltamivir receive abdominal pain, hearing disorder, epistaxis and conjunctivitis. In most cases, such reactions occur once and independently disappear, despite the continuation of therapy. Such phenomena do not require the abolition of the medication.

After the appointment of an antiviral drug in children and adolescents, undesirable effects also appear. These include phenomena such as a rash, toxic epidermal necrolysis, swelling of the tongue or face, arrhythmia, confusion, convulsions and worsening of the course of diabetes.

Drug Interactions

The information obtained during pharmacokinetic and pharmacological studies, says that the development of clinically significant drug interactions in this drug is unlikely.

In the instructions attached to the drug, it is said that the simultaneous use of this drug with probenecid results in an increase in the AUC of the active metabolite by a factor of 2. But dose adjustment is not required.

Cases of overdose

What signs are observed in patients taking high doses of Oseltamivir? The reviews and instructions say that until now no such cases have occurred. However, single doses of an antiviral drug may cause vomiting or nausea.

To eliminate such symptoms, symptomatic therapy is carried out.

Special recommendations for taking medication

What should the patient know before taking Oseltamivir? Instructions for use (in children and adults there may be different side effects) indicates that this drug is not applicable for annual vaccination. It does not prevent the development of complications that may occur in viral disease, as well as in bacterial infection.

Analogs of the medicinal product

"Oseltamivir" is a medicinal product intended for the treatment and prevention of influenza. It is an antiviral agent that refers to inhibitors of neuraminidases. This medication is widely known as Tamiflu. There are no structural analogues to it. The closest, but slightly inferior in effectiveness, are the following substitute drugs: Relenc, Arbidol, Flustol, Kagocel and others.

Reviews and evaluations of the effectiveness of the drug

According to the test results obtained in the United States and Mexico, new viruses are sensitive to neuraminidase inhibitors ("Zanamivir" and "Oseltamivir"), but they are resistant to another group - adamantanes ("Rimantadine", "Amantadine"), .

Also it should be noted that the experts have never established the effectiveness of this medication in the treatment of influenza in people with chronic cardiac and respiratory diseases.

According to doctors' reviews, this drug reduces the duration of symptoms for 1 day, but this is only if the treatment was started in the first few hours after contact with the patient.

To date, there is no reliable information about whether this drug affects the frequency of complications of viral or infectious diseases.