Oseltamivir Phosphate Capsules

Oseltamivir phosphate is a prodrug of its active metabolite, and its active metabolite (oseltamivir carboxylate) is a selective inhibitor of influenza virus neuraminidase. Neuraminidase is a glycoprotein enzyme on the surface of the virus, and its activity is essential for the release of newly formed virus particles from infected cells and the further spread of infectious viruses in the human body. The active metabolite of oseltamivir phosphate can inhibit the neuraminidase activity of influenza A and B viruses. The half-inhibitory concentration of viral neuraminidase activity in vitro is as low as nanogram levels. The active metabolite was observed to inhibit influenza virus growth in vitro, and it was also observed to inhibit influenza virus replication and pathogenicity in vivo. This product reduces the spread of influenza A or B viruses by inhibiting the release of the virus from infected cells. Studies on naturally acquired and laboratory influenza have shown that the use of oseltamivir phosphate does not affect the normal humoral immune response to infection in the human body. The antibody response to inactivated vaccines was not affected by oseltamivir phosphate treatment.

Oseltamivir phosphate

This product is a grayish white and light yellow two-color capsule, and the contents are white to yellowish white powder.

1. For the treatment of influenza A and B in adults and children aged 1 year and over (oseltamivir phosphate can effectively treat influenza A and B, but there is not much clinical application data for influenza B). 2. For the prevention of influenza A and B in adults and adolescents aged 13 years and over.

Oseltamivir phosphate can be taken with or without food. However, for some patients, taking the drug with food can improve the tolerability of the drug. Treatment of influenza should be started on the first or second day of the onset of influenza symptoms (ideally within 36 hours). Dosage instructions for adults and adolescents The recommended oral dose of oseltamivir phosphate in adults and adolescents over 13 years of age is 75 mg twice a day for 5 days. Children The following weight-dose table is recommended for children over 1 year of age Recommended weight dose (taken for 5 days) ≤ 15 kg 15-23 kg 23-40 kg 40 kg 30 mg, 2 times a day 45 mg, 2 times a day 60 mg, 2 times a day 75 mg, 2 times a day Prevention of influenza The recommended oral dose of oseltamivir phosphate for the prevention of influenza after close contact with influenza patients is 75 mg once a day for at least 7 days. The medication should also be started within 2 days of close contact. The recommended dose of oseltamivir phosphate for the prevention of influenza during the influenza season is 75 mg once a day. Data show that continuous use of the drug for 6 weeks is safe and effective. It has a preventive effect during the medication period. Medication guidance for special populations Influenza treatment in patients with renal insufficiency: No dose adjustment is required for patients with creatinine clearance greater than 30 ml/min. For patients with creatinine clearance of 10-30 ml/min, the recommended dose is reduced to 75 mg once a day for 5 days. Oseltamivir phosphate is not recommended for patients with creatinine clearance less than 10 ml/min and patients with severe renal failure who require regular hemodialysis or continuous peritoneal dialysis.

1. Since the launch of oseltamivir phosphate, reports of self-harm and delirium in patients with influenza who were treated with oseltamivir phosphate have been received. Most of the reports came from Japan, mainly pediatric patients, but the correlation between oseltamivir phosphate and these events is still unclear. During treatment with this drug, patients should be closely monitored for abnormal behaviors such as self-harm and delirium. 2. There is no evidence that oseltamivir phosphate is effective for diseases other than influenza A and influenza B. 3. The safety and effectiveness of oseltamivir for the treatment of influenza in children under 1 year old have not been determined. 4. The safety and effectiveness of oseltamivir for the prevention of influenza in children under 13 years old have not been determined. 5. There is no data on the safety and effectiveness of oseltamivir in patients who have poor or unstable health and must be hospitalized. 6. The safety and effectiveness of oseltamivir in the treatment and prevention of influenza in immunosuppressed patients has not been determined. 7. The effectiveness of oseltamivir in the treatment of influenza in patients with chronic heart and/or respiratory diseases has not been determined. There is no difference in the incidence of complications observed between the treatment group and the placebo group in these populations. 8. Oseltamivir phosphate cannot replace influenza vaccines. The use of oseltamivir phosphate should not affect annual influenza vaccination. The preventive effect of oseltamivir phosphate against influenza is only available when the drug is used. Oseltamivir phosphate should only be considered for the treatment and prevention of influenza after reliable epidemiological data show that influenza virus infection has occurred in the community. 9. The recommended doses for treatment and prevention should be adjusted for patients with creatinine clearance of 10-30 ml/min. Oseltamivir phosphate is not recommended for patients with creatinine clearance less than 10 ml/min, and patients with severe renal failure who require regular hemodialysis and continuous peritoneal dialysis (see [Pharmacokinetics] and [Dosage and Administration]). 10. Data on drug dosage for children without renal failure. 11. No effect of the drug on the patient's ability to drive a vehicle or operate machinery has been observed. However, the possible impact of influenza itself must be considered.

It is contraindicated for those who are allergic to any ingredient of this product.

Precautions for children: The safety and effectiveness of oseltamivir phosphate for children under 1 year old have not been determined. Precautions for pregnancy and lactation: 1. Pregnancy In animal reproduction studies conducted on rats and rabbits, no teratogenicity of the drug was observed. In three studies of rats before and after delivery, oseltamivir phosphate was given to rats at toxic doses. In two studies, unweaned rat pups showed growth retardation and prolonged labor. In the fertility and reproductive toxicity studies conducted on rats, the dose of oseltamivir used did not affect the fertility of rats. The drug exposure received by embryos of rats and rabbits is about 15-20% of that of rats and rabbits. There is currently insufficient data on the treatment of pregnant women with oseltamivir phosphate, so it is impossible to evaluate the potential possibility of fetal malformation or fetal toxicity caused by oseltamivir phosphate. Therefore, pregnant women can only take oseltamivir phosphate when the expected benefits outweigh the potential risks. 2. Lactation For lactating rats, oseltamivir and its active metabolites (oseltamivir carboxylate) can be secreted in breast milk. It is not known whether oseltamivir and its active metabolites are secreted in human milk. Preliminary inference from animal test data indicates that approximately 0.01 mg of oseltamivir and 0.3 mg of active metabolites are secreted in human milk daily. Therefore, oseltamivir phosphate should only be taken when the expected benefit to the nursing mother outweighs the potential risk to the infant. Elderly precautions: The dose does not need to be adjusted for treatment and prevention of elderly patients (see [Pharmacokinetics]).

Interaction with influenza vaccine: There is no evaluation of the interaction between oseltamivir phosphate and live attenuated influenza vaccine. However, due to the possible interaction between the two, oseltamivir phosphate should not be taken within two weeks of taking live attenuated influenza vaccine, and live attenuated influenza vaccine should not be used within 48 hours after taking oseltamivir phosphate unless clinically necessary. Because oseltamivir phosphate, as an antiviral drug, may inhibit the replication of live vaccine viruses. Trivalent inactivated influenza vaccine can be used at any time before or after taking oseltamivir phosphate. Pharmacological and pharmacokinetic study data show that there is basically no significant clinically significant interaction between oseltamivir phosphate and other drugs. Oseltamivir phosphate is rapidly converted into active metabolites (oseltamivir carboxylate) by esterases mainly distributed in the liver. There are few reports of drug interactions related to competing esterases in the literature. The low protein binding rate of oseltamivir and its active metabolites suggests that drug interactions related to protein binding are unlikely to occur. In vitro studies have shown that neither oseltamivir phosphate nor its active metabolites are good substrates for P450 mixed function oxidase or glucuronyl transferase (see [Pharmacokinetics]). There is no mechanism of drug interaction with oral contraceptives. Cimetidine is a nonspecific inhibitor of cytochrome P450 isoenzymes and can compete with alkaline or cationic substances for renal tubular secretion, but it has no effect on the plasma concentration of oseltamivir or its active metabolites. Therefore, clinical drug interactions related to changes in gastric pH (antacids) and competitive clearance with the renal tubular secretion pathway are unlikely to occur. However, there are no in vivo studies on the interaction between oseltamivir phosphate and antacids. Drug interactions related to competitive secretion with renal tubules are unlikely to have important clinical significance, because most drugs have a wide safety range, and the excretion of active metabolites of oseltamivir phosphate has two pathways: glomerular filtration and renal tubular secretion, and the clearance capacity of these two pathways is very large. However, it should be used with caution in combination with drugs that are also secreted by the kidneys and have a narrow safety range (such as chlorsulfuronamide, methotrexate, and phenylbutazone). When used in combination with probenecid, the body utilization of active metabolites is increased by 2 times due to the decreased ability of the renal tubular secretion. However, due to the wide safety margin of active metabolites, no dose adjustment is required when co-administered with probenecid. Co-administration with amoxicillin does not change the plasma concentrations of the two drugs, indicating that the competitive effect of anion pathway elimination is not significant. In post-marketing surveillance, there have been case reports of interactions with ganciclovir, which is also secreted through the renal tubules. Co-administration with paracetamol (acetaminophen) did not change the plasma concentrations of oseltamivir, its active metabolites, or paracetamol. No changes in the pharmacokinetic parameters of oseltamivir, its active metabolite (oseltamivir carboxylate), or aspirin were found when oseltamivir (75 mg, twice daily for 4 days) was taken with aspirin (single dose of 900 mg). No changes in the pharmacokinetic parameters of oseltamivir and its active metabolite (oseltamivir carboxylate) were found when oseltamivir (single dose of 150 mg) was taken with a single dose of an antacid containing aluminum hydroxide and magnesium hydroxide or a single dose of an antacid containing calcium carbonate. In the Phase III clinical study of influenza treatment and influenza prevention, oseltamivir phosphate was used in combination with some commonly used drugs, such as ACE inhibitors (enalapril, captopril), thiazide diuretics (bendroflumethiazide), antibiotics (penicillin, cephalosporin, azithromycin, erythromycin, doxycycline), H2 receptor blockers (ranitidine, cimetidine), beta-blockers (propranolol), xanthines (theophylline), sympathomimetic drugs (pseudoephedrine), opioids (codeine), steroid hormones, inhaled bronchodilators and analgesics (aspirin, ibuprofen and paracetamol). No adverse events were observed or their incidence was changed when oseltamivir phosphate was used in combination with these drugs.

seal

75mg (as oseltamivir)

24 months

Yichang HEC Changjiang Pharmaceutical Co., Ltd.

• Founded in:

  2001-08-08

• Address:

  No. 38, Binjiang Road, Yidu City, Yichang City, Hubei Province

• Tax NO.:

  91420000730842584F

• Registered Funds:

  879.9677 million yuan

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