Tamiflu
Tamiflu: instructions for use and reviews
- 1. Release form and composition
- 2. Pharmacological properties
- 3. Indications for use
- 4. Contraindications
- 5. Instructions for use: method and dosage
- 6. Side effects
- 7. Overdose
- 8. Special instructions
- 9. Application during pregnancy and lactation
- 10. In case of impaired renal function
- 11. For violations of liver function
- 12. Use in the elderly
- 13. Drug interactions
- 14. Analogs
- 15. Terms and conditions of storage
- 16. Terms of dispensing from pharmacies
- 17. Reviews
- 18. Price in pharmacies
Latin name: Tamiflu
ATX code: J05AH02
Active ingredient: Oseltamivir (Oseltamyvir)
Manufacturer: GmbH, Catalent Germany Schorndorf (Germany), Ltd. F. Hoffmann-La Roche (Switzerland)
Description and photo update: 2019-12-08
Prices in pharmacies: from 1083 rubles.
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Tamiflu is an antiviral drug used to prevent and treat influenza.
Release form and composition
Tamiflu comes in the following forms:
- capsules: hard gelatinous, size No. 4 (dosage 30 mg and 45 mg) or No. 2 (dosage 75 mg), opaque, with a body and cap of light yellow (dosage 30 mg) or gray (dosage 45 mg) color, or with gray body and light yellow cap (dosage 75 mg); there are light blue inscriptions on the body and cap of the capsule (on the body - the name of the manufacturer, on the cap - indication of the dosage); the contents of the capsules are white or yellowish-white powder (10 pcs. in blisters, one blister in a carton);
- powder for preparation of suspension for oral administration: granular fine, white or light yellow color, with a fruity aroma; clumping is acceptable; ready-made suspension - opaque, from white to light yellow (30 g each in light-protective glass vials, in a cardboard package with a septum, one vial complete with a measuring cup, plastic adapter and dosing syringe).
Composition for 1 capsule Tamiflu:
- active ingredient: oseltamivir (in the form of oseltamivir phosphate) - 30 mg, 45 mg or 75 mg;
- auxiliary components: sodium stearyl fumarate, povidone, talc, sodium croscarmellose, pregelatinized starch;
- capsule shell: dye iron oxide yellow (dosage 30 mg and 75 mg), dye iron oxide red (dosage 30 mg and 75 mg), dye iron oxide black (dosage 45 mg and 75 mg), titanium dioxide, gelatin;
- ink for the inscription on the capsule: butanol, ethanol, methylated alcohol, shellac, indigo carmine-based aluminum varnish, titanium dioxide.
Composition for 1 g of Tamiflu powder:
- active substance: oseltamivir (in the form of oseltamivir phosphate) - 30 mg;
- auxiliary components: xanthan gum, sodium saccharinate, sorbitol, sodium benzoate, sodium dihydrogen citrate, titanium dioxide, fruit flavor.
The finished suspension contains Tamiflu oseltamivir in an amount of 12 mg / ml.
Pharmacological properties
Pharmacodynamics
Oseltamivir, the active component of Tamiflu, is a prodrug. Oseltamivir carboxylate, which is its active metabolite, is a selective inhibitor of influenza A and B neuraminidases. This enzyme, which activates the release of viruses from cells affected by them, provokes the multiplication and spread of harmful microorganisms throughout the body, including the epithelial layer of the respiratory tract. When using oseltamivir, the processes of viral replication are inhibited, and their pathogenicity is reduced. The activity of the release and spread of pathological agents from the organism of the carrier of the disease is also inhibited.
Tamiflu facilitates the course of the disease and shortens its duration, reducing the risk of developing complications such as otitis media, sinusitis, bronchitis or pneumonia. Clinical studies have shown that in children under 12 years of age, the duration of the disease is reduced by an average of 2 days.
When taken for prophylaxis by persons in contact with infected patients, family members of the patient are less likely to get any type of influenza by 92%. A clinically significant effect of the drug on the intensity of the body's response to the penetration of the virus into it was not found, antibodies are produced in the same way as without the use of Tamiflu. There are no confirmed cases of drug resistance formation.
Pharmacokinetics
Oseltamivir phosphate is absorbed at a high rate and almost completely from the gastrointestinal tract, where it turns into an active metabolite with the participation of hepatic and intestinal esterases. It is possible to identify the active metabolite in the blood plasma within 30 minutes after administration. The maximum content of the metabolite in the blood is reached after 120-180 minutes. The plasma concentration of the metabolite is 20 times that of oseltamivir itself.
Pharmacokinetic characteristics of Tamiflu do not depend on food intake. It penetrates into the tissues of the trachea, lungs, middle ear, mucous membrane of the nasopharynx and bronchi.
The metabolite binds to blood plasma proteins by about 3%, and the degree of binding to them of oseltamivir itself reaches 50%, but the pharmacodynamic parameters remain unchanged.
Oseltamivir and its active metabolite are excreted mainly in the urine and to a small extent in the feces. The half-life is approximately 5-10 hours.
Elimination of oseltamivir from the body is associated with certain difficulties in patients with severe renal dysfunction. AUC (area under the concentration-time pharmacokinetic curve) in such patients is inversely proportional to the degree of organ damage. No such dependence was observed in patients with liver dysfunctions.
Elderly patients do not need dose adjustment of Tamiflu. In children under 12 years of age, the metabolism of oseltamivir is accelerated: it is excreted from the body almost 2 times faster. Therefore, dose adjustment is necessary for them.
Indications for use
Tamiflu is used in adults and children over one year old for the prevention and treatment of influenza.
The use of the drug for prophylactic purposes is especially indicated for adults and adolescents over 12 years old, who are in groups where the risk of infection with the virus is quite high (large industrial institutions, school educational institutions, military units).
Contraindications
- chronic renal failure (creatinine clearance 10 ml / min or less, chronic peritoneal dialysis, continuous hemodialysis);
- children under 1 year of age (since the safety and effectiveness of the drug in children under 1 year of age have not been established)
- increased individual sensitivity to any ingredient of the drug.
Tamiflu is prescribed with caution to pregnant and lactating women, as well as to patients with severely impaired liver function.
Instructions for the use of Tamiflu: method and dosage
The drug is taken orally, regardless of food intake, however, Tamiflu's tolerance improves if taken with meals.
Treatment with the drug should be started no later than two days from the moment the first symptoms of the disease appear. Recommended doses:
- adult patients and adolescents 12 years and older: 75 mg (in the form of capsules or suspension) twice a day, course duration - 5 days. When taking doses of more than 150 mg per day, an increase in the effect is not observed;
- children aged 8 years and older (weighing 40 kg or more): 75 mg twice a day in the form of capsules, provided that the child can swallow the capsules; if taking capsules for any reason is not possible, the child is prescribed Tamiflu in the form of a suspension. The course of treatment is 5 days;
- children aged 1 year and older: children weighing 15 kg or less - 30 mg twice a day; children weighing 15-23 kg - 45 mg twice a day; children weighing 23-40 kg - 60 mg twice a day; children weighing more than 40 kg - 75 mg twice a day. The course of treatment is 5 days.
The use of Tamiflu for prophylaxis should be started no later than the first 2 days after contact with an infected person and continue taking the drug for at least 10 days. During the seasonal flu epidemic, the course of taking Tamiflu is 6 weeks. The drug is taken in the same doses as during treatment, but not twice, but once a day. The preventive effect of Tamiflu lasts as long as it lasts.
Recommendations for preparing a suspension for oral administration:
- Take a bottle of powder, gently tap it with your finger so that the contents are distributed at the bottom of the bottle.
- Using the supplied measuring cup, measure out 52 ml of water.
- Add a measured volume of water to the bottle with the powder, close it with a cap and shake for 15 seconds.
- Remove the cap from the bottle and insert the adapter.
- To ensure the correct position of the adapter, screw the bottle tightly with the cap.
To dispense the finished suspension, you must use the supplied syringe, which is marked with labels indicating the dose levels.
The suspension should be shaken before each use.
If there are signs of "aging" of the capsules and in cases where adults or children over 8 years old are not able to swallow the capsule, and Tamiflu is not available in powder form for preparation of a suspension, it is necessary to carefully open the capsule and mix its contents with one teaspoon of the sweetened product to hide the bitter taste of the capsule contents. You can use yogurt, honey, applesauce, chocolate syrup, sweetened condensed milk, table sugar, or light brown sugar dissolved in water. The mixture should be thoroughly mixed and allowed to be swallowed in full by the patient immediately after preparation.
Patients with mild to moderate hepatic insufficiency, patients with impaired renal function (creatinine clearance more than 30 ml / min), as well as elderly people, do not require dose adjustment.
With a creatinine clearance of 10-30 ml / min, it is necessary to reduce the dose of Tamiflu to 75 mg once a day every day for 5 days (during treatment). In the prevention of influenza in patients with creatinine clearance of 10-30 ml / min, the dose should be reduced to 30 mg daily as a suspension or the patient should be transferred to the drug every other day at a dose of 75 mg per day.
Side effects
In adult patients, vomiting and nausea are most often observed, which most often occur after taking the first dose of Tamiflu, are transient and go away on their own, without requiring discontinuation of the drug.
With a frequency of 1% or more, the following side reactions were also encountered: dizziness, weakness, sleep disturbances, headache, bronchitis, cough, abdominal pain, diarrhea, rhinorrhea, upper respiratory tract infections, dyspeptic disorders, pain of various localization.
In children, vomiting was most often observed, as well as nausea, bronchitis, asthma (including its exacerbation), sinusitis, pneumonia, epistaxis, conjunctivitis, acute otitis media, hearing disorders, lymphadenopathy, diarrhea, abdominal pain and dermatitis … Some of these side effects came on suddenly and stopped on their own without causing discontinuation of therapy.
During the post-marketing observation period, adverse reactions from the following systems and organs were noted:
- gastrointestinal tract and liver: rarely - gastrointestinal bleeding; very rarely - increased activity of liver enzymes, hepatitis;
- neuropsychic sphere: convulsions, abnormal behavior, hallucinations, anxiety, impaired consciousness, agitation, delirium, nightmares, disorientation in space and time (however, the role of Tamiflu in the occurrence of the listed phenomena is not fully known, since similar disorders were noted in others patients with influenza who have not received the drug);
- skin and subcutaneous tissue: rarely - urticaria, dermatitis, eczema, skin rash; very rarely - Quincke's edema, anaphylactoid and anaphylactic reactions, erythema multiforme, Lyell's syndrome.
Overdose
During clinical studies and post-marketing use of Tamiflu, cases of overdose have been reported. Mostly they were not accompanied by any undesirable phenomena. In other cases, the symptoms of overdose were increased side effects of the drug.
special instructions
During the use of Tamiflu, it is recommended to establish careful observation of the behavior of patients in order to detect early signs of abnormal behavior.
The effectiveness of the drug for other diseases (except for influenza A and B) has not been established.
One bottle of Tamiflu in powder form contains 25.713 g of sorbitol. When the drug is prescribed in a dose of 45 mg twice a day, 2.6 g of sorbitol enters the patient's body. This amount of sorbitol exceeds the daily allowance for patients with congenital fructose intolerance.
The prepared suspension can be stored for 10 days at a temperature not exceeding 25 ° C or for 17 days at a temperature of + 2… +8 ° C.
Influence on the ability to drive vehicles and complex mechanisms
There have been no studies examining the effect of Tamiflu on the ability to drive transport and engage in activities that require increased concentration and immediate psychomotor reactions. The data in the safety profile suggest a minimal effect of the drug on the performance of this work.
Application during pregnancy and lactation
According to the instructions, Tamiflu belongs to category B (in accordance with the FDA classification). During studies in which the toxic effect of the drug on reproductive performance was studied using the example of animals (rabbits, rats), no teratogenic effect was found. Experiments on rats did not reveal a negative effect of oseltamivir on fertility. Fetal exposure did not exceed 15-20% of that of the mother.
No controlled studies have been conducted in pregnant women. In accordance with the limited information obtained from post-marketing reports, animal experiments and retrospective monitoring of survival, there is no direct or indirect effect of Tamiflu on pregnancy and embryonic or postnatal development of the child. When prescribing a drug to pregnant women, it is necessary to take into account both safety information and the course of pregnancy, as well as the degree of pathogenicity of influenza virus strains circulating in the environment.
During preclinical studies, it was found that oseltamivir and its active metabolite penetrate into the milk of rats feeding offspring. Information on the excretion of the active ingredient Tamiflu with breast milk in humans and the use of oseltamivir by lactating women is somewhat limited. Oseltamivir and its active metabolite in small doses penetrate into breast milk, after which their subtherapeutic concentrations are found in the blood of an infant.
The administration of oseltamivir to nursing patients also requires consideration of the characteristics of comorbidities and the degree of pathogenicity of the circulating influenza virus strain.
With impaired renal function
When treating patients with impaired renal function with CC more than 60 ml / min, dose adjustment is not necessary. Patients with CC 30-60 ml / min should take Tamiflu at a dosage of no more than 30 mg 2 times a day for 5 days. For patients with CC 10-30 ml / min, the drug is prescribed in a dosage of 30 mg once a day for 5 days. Patients on continuous hemodialysis can take Tamiflu at an initial dose of 30 mg before dialysis, if the symptoms of influenza appear within 48 hours between dialysis sessions. To maintain a therapeutic plasma oseltamivir concentration, Tamiflu is recommended to be taken 30 mg after each dialysis session. Patients on peritoneal dialysis should take the drug at an initial dose of 30 mg before dialysis, and then at 30 mg for 5 days. Pharmacokinetic parameters in patients with diagnosed end-stage renal failure (CC less than 10 ml / min), not undergoing dialysis, have not been studied. As a result, there are no recommendations on the selection of a dosage regimen in this category of patients.
When taking Tamiflu for prophylactic purposes in patients with CC more than 60 ml / min, there is no need for dose adjustment. For patients with CC 30-60 ml / min, the drug should be prescribed at a dosage of 30 mg once a day. In patients with CC 10-30 ml / min, it is recommended to reduce the dose of the drug to 30 mg, which are taken every other day. Patients on continuous hemodialysis can take Tamiflu at an initial dose of 30 mg before the first dialysis session. To keep the oseltamivir plasma level at a therapeutic level, the drug should be taken at 30 mg after each subsequent odd dialysis session. Patients on peritoneal dialysis should take Tamiflu at an initial dose of 30 mg before dialysis, then 30 mg every 7 days.
For violations of liver function
Patients with liver dysfunctions of mild and moderate severity do not need to adjust the dose of Tamiflu in the treatment and prevention of influenza. In patients with severe liver dysfunctions, the pharmacokinetic features and safety of the drug have not been studied.
Use in the elderly
In elderly and senile patients, there is no need to adjust the therapy regimen for the treatment and prevention of influenza.
Drug interactions
Clinically significant interactions of Tamiflu with other drugs are unlikely.
Analogs
Tamiflu analogues are: Relenza, Arbidol, Oseltamivir, Flustop.
Terms and conditions of storage
Store in places inaccessible to children at a temperature not exceeding 25 ° C.
The shelf life of the powder is 2 years, the capsules are 7 years.
Terms of dispensing from pharmacies
Dispensed by prescription.
Reviews about Tamiflu
According to reviews, Tamiflu is well tolerated and effective against influenza viruses. Patients note that when taking the drug, they get sick much less often and more easily, since it facilitates the course of the disease. In some cases, side effects are observed, the most common of which are nausea and diarrhea (mainly in children).
Most parents are satisfied with the effect of Tamiflu when administered to their children. In many cases, taking a prophylactic drug before going to kindergarten or school will help prevent your child from getting the flu virus.
Price for Tamiflu in pharmacies
The approximate price of Tamiflu in capsules with a dosage of 75 mg is 1215–1405 rubles (for a package of 10 pcs.). Powder for the preparation of a suspension for oral administration is currently not available for sale.
Tamiflu: prices in online pharmacies
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Drug name Price Pharmacy |
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Tamiflu 75 mg capsule 10 pcs. 1083 RUB Buy |
Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
Information about the drug is generalized, provided for informational purposes only and does not replace the official instructions. Self-medication is hazardous to health!
