Relenza
Relenza: instructions for use and reviews
- 1. Release form and composition
- 2. Pharmacological properties
- 3. Indications for use
- 4. Contraindications
- 5. Method of application and dosage
- 6. Side effects
- 7. Overdose
- 8. Special instructions
- 9. Application during pregnancy and lactation
- 10. Use in childhood
- 11. Drug interactions
- 12. Analogs
- 13. Terms and conditions of storage
- 14. Terms of dispensing from pharmacies
- 15. Reviews
- 16. Price in pharmacies
Latin name: Relenza
ATX code: J05AH01
Active ingredient: zanamivir (zanamivir)
Producer: Glaxo Wellcome Production (France)
Description and photo updated: 2018-23-11
Prices in pharmacies: from 436 rubles.
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Relenza is an antiviral drug used in the treatment of influenza A and B.
Release form and composition
The dosage form of Relenza is a dosed powder for inhalation: from almost white to white [in a cardboard box 1 bottle containing 20 doses (5 rotadisks of 4 cells), complete with Diskhaler].
Composition of 1 dose of powder:
- active substance: zanamivir (micronized) - 5 mg;
- auxiliary component: lactose monohydrate - up to 25 mg.
Pharmacological properties
Pharmacodynamics
Relenza is an antiviral drug, a potent and highly selective inhibitor of neuraminidase (a surface enzyme of the influenza virus). Due to viral neuraminidase, viral particles are released from the infected cell and it is possible to accelerate the penetration of the virus through the mucous barrier to the surface of epithelial cells, which ensures infection of other cells of the respiratory tract.
The inhibitory activity of zanamivir includes all 9 subtypes of influenza virus neuraminidases, including virulent and circulating for various species. Half the inhibitory concentration (IC 50) for virus strains A and B is 0.09–95.2 pM.
Influenza virus replication is limited to cells of the surface epithelium of the respiratory tract. Due to the effect of zanamivir in the extracellular space, the reproduction of two types of influenza A and B virus is reduced and the release of viral particles from the cells of the surface epithelium of the respiratory tract is prevented.
For inhaled use, the efficacy of zanamivir has been confirmed in controlled clinical trials. The use of the drug as a therapy for acute infections caused by the influenza virus, compared with placebo, led to a decrease in the release of the virus. The development of resistance to zanamivir with normal immunity was not observed.
The use of Relenza in at-risk healthy people in doses used in the treatment of influenza led to an improvement in symptoms and a reduction in the duration of illness. A combined analysis of the results of the Phase III trials showed that the median time to symptom relief was reduced to one and a half days. There was also a decrease in the number of complications after the flu and the use of antibiotics used in their treatment.
Zanamivir is most effective when therapy is started as soon as possible after the first symptoms of the disease appear. It has also been proven to be effective when used as a prophylactic agent.
Pharmacokinetics
Zanamivir is characterized by a low absolute bioavailability (on average after oral administration - 2%). Absorbed after oral inhalation of about 10-20% of the administered dose. C max (maximum concentration of the substance) after a single dose of 10 mg is 97 ng / ml, the time to reach it is 1.25 hours. Due to the low degree of absorption, there is a low systemic concentration and an insignificant area under the pharmacokinetic curve "concentration - time". Due to low absorption, the plasma concentration of zanamivir in the blood is low (with repeated inhalations, the indicators remain at a low level).
The binding of the substance to blood plasma proteins is <10%. V d (volume of distribution) in adults is approximately 16 liters, which roughly corresponds to the volume of extracellular fluid. After oral inhalation, zanamivir is deposited in the respiratory tract in high concentrations and ensures the delivery of Relenza to the entrance gate of the infection. In the epithelial layer of the respiratory tract after inhalation of 10 mg of zanamivir, the concentration of the substance significantly exceeds the average IC 50 for neuraminidase (12 hours after inhalation - 340 times, 24 hours after inhalation - 52 times). This provides a rapid inhibition of the viral enzyme. The main sites of deposition are the lungs and the oropharynx (the average is 13.2% and 77.6%, respectively).
Zanamivir is not metabolized; it is excreted unchanged by the kidneys.
After oral inhalation, T 1/2 (half-life) from blood plasma ranges from 2.6-5.05 hours. The total clearance rate is 2.5-10.9 l / h.
Indications for use
According to the instructions, Relenza is prescribed for the treatment and prevention of infection caused by influenza A and B viruses.
Contraindications
Absolute:
- age up to 5 years;
- individual intolerance to the components of the drug.
Relative (Relenza is prescribed under medical supervision):
- diseases of the respiratory tract, proceeding with bronchospasm, including a burdened history;
- lactase deficiency, lactose intolerance, glucose-galactose malabsorption;
- pregnancy (especially the first trimester) and lactation.
Instructions for use of Relenza: method and dosage
Relenza is intended solely for oral inhalation use. In order to ensure the correct use of the drug, the Diskhaler included in the kit should be used.
In cases of necessity of simultaneous therapy with other inhaled drugs (for example, with fast-acting bronchodilators), it is preferable to use them before Relenza.
Recommended application scheme:
- treatment: 2 times a day, two inhalations for 5 days. The total daily dose is 20 mg. When the first symptoms of the disease appear, it is recommended to start therapy as early as possible (preferably within 2 days);
- prevention: once a day, two inhalations for 10 days (if necessary, up to 30 days). The total daily dose is 10 mg.
For inhalation of zanamivir, the Diskhaler device is used, which consists of the following parts:
- a case with a lid and a plastic needle designed to pierce the rotadisk cell;
- a pull-out tray that includes a mouthpiece and a rotating wheel on which a rotadisk is placed;
- case for the mouthpiece.
Rotadisk is a blister with four cells, each containing 5 mg of zanamivir. Rotadisc can be stored in the device for inhalation; the blister must be pierced immediately before inhalation of the drug. Failure to follow this recommendation can lead to disruption of Diskhaler's operation and, accordingly, reduce the effectiveness of Relenza.
You cannot pierce the rotadisk until it is placed in the Dischaler.
Algorithm for loading rotadisk into Diskhaler and for inhalation:
- Remove the cover from the mouthpiece, make sure the mouthpiece is clean inside and out.
- Pull out the drawer with care, gripping the corners of the drawer until the plastic clips come out. The tray extends as far as it will go so that the notches on the side of the clips are visible.
- Pull the tray out completely by squeezing the notches on the side of the clips with your thumb and forefinger.
- Place the rotadisk on the wheel, cells down.
- Reinsert the tray into the Dischaler.
- Lift the dischaler lid up to the stop to pierce the lower and upper packaging (foil) of the rotadisk. Do not lift the cover before the drawer is fully installed.
- Close the lid.
- Place the mouthpiece between the lips and teeth after exhaling completely, do not close the air holes on either side of the mouthpiece. Take a slow deep breath through your mouth (not through your nose).
- Remove the mouthpiece from your mouth.
- Hold your breath for as long as possible, then exhale slowly. You cannot exhale into the inhaler.
- Gently pull out the drawer once, without pressing the clips, until it stops and push it back in. This will rotate the rotadisk by one cell, and it will be ready for the next inhalation.
Each rotadisk contains 4 cells. After four inhalations, the empty rotadisc is replaced with a new one.
Children should be supervised to use the inhalation device.
Side effects
Usually Relenza is well tolerated by patients.
Possible adverse reactions (> 10% - very common;> 1% and 0.1% and 0.01% and <0.1% - rarely; <0.01% - very rare):
- nervous system: very rarely - vasovagal reactions (observed in patients with symptoms of the influenza virus in the form of dehydration and fever, which were observed immediately after inhalation of zanamivir);
- immune system: very rarely - allergic reactions, including anaphylactoid / anaphylactic reactions, oropharyngeal and facial edema;
- cardiovascular system: fainting, arrhythmia;
- psyche: with an unknown frequency - confusion, convulsions, hallucinations, anxiety, agitation, behavioral disturbances, delirium, delirium (observed mainly in children and adolescents; neuropsychiatric symptoms and convulsions were also noted in patients who did not use Relenza);
- skin and subcutaneous tissues: very rarely - urticaria, rash, severe skin reactions, including toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme;
- respiratory system: very rarely - shortness of breath, bronchospasm.
Overdose
Due to the peculiarities of the Relenza dosage form, the route of administration and the low bioavailability of the active substance, accidental overdose is unlikely. In the context of clinical studies, adverse reactions with intravenous administration in a daily dose of 1200 mg for 5 days were not registered.
Therapy: hemodialysis (can be considered as a treatment option because zanamivir has a low molecular weight, low plasma protein binding and low Vd).
special instructions
Influenza can occur with increased airway hyperresponsiveness. There are very rare reports of worsening pulmonary function and / or attacks of bronchospasm after inhalation of zanamivir in patients with influenza therapy. In some cases, there was no history of chronic respiratory diseases. If such symptoms appear, you need to cancel Relenza and consult a doctor for a medical examination. Patients with chronic respiratory diseases during the use of the drug should have a fast-acting bronchodilator with them.
In severe bronchial asthma, an assessment of the intended benefits and possible risks should be carried out before starting treatment. Treatment should not be carried out without proper medical supervision. In patients with severe chronic obstructive pulmonary disease and bronchial asthma during the use of Relenza, the therapy of the underlying disease should be optimized. It is necessary to take into account the potential danger of developing bronchospasm.
Do not use Relenza powder for solution for a nebulizer or ventilator.
Influenza can be accompanied by a variety of behavioral and neurological symptoms. According to reports during the period of post-registration studies, in patients infected with the influenza virus and using inhalation zanamivir, the development of the following disorders was noted: delirium, seizures, hallucinations and deviant behavior. Most often they appeared in the early stages of the disease, in most cases they began suddenly and had a quick resolution. A reliably causal relationship between the treatment of Relenza and the above violations has not been established. In cases of the appearance of any neuropsychiatric symptoms, before further treatment, it is necessary to assess the ratio of benefit to risk.
Application during pregnancy and lactation
Relenza during pregnancy (especially during the first trimester) and lactation can be used only after assessing the balance of benefits and risks, which is associated with insufficient clinical data.
Pediatric use
It is contraindicated to administer Relenza therapy to patients under 5 years of age.
Drug interactions
Clinical interactions are unlikely.
Analogs
Relenza's analogs are: Tamiflu, Acyclovir, Nucleavir, Amizon, Rebetol, Virogel, Valtrex, Virgan, Virolex.
Terms and conditions of storage
Store at temperatures up to 30 ° C. Keep out of the reach of children.
The shelf life is 7 years.
Terms of dispensing from pharmacies
Dispensed by prescription.
Reviews about Relenze
According to reviews, Relenza is fast acting. Other advantages indicate the possibility of using the drug in children from 5 years of age, long shelf life and the presence of an inhaler in the kit. The main disadvantage is the high cost.
Price for Relenza in pharmacies
The approximate price for Relenza (5 rotadisks included with Dischaler) is 874–1180 rubles.
Relenza: prices in online pharmacies
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Drug name Price Pharmacy |
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Relenza 5mg / dose - 4 doses in rotadisk, dosed powder for inhalation complete with the Diskhaler inhaler 5 pcs. 436 r Buy |
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Relenza powder for in. dosage. 5mg / dose 4 doses 5 pcs. 1143 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!
