Dectova (Zanamivir): Intravenous Influenza Treatment
Neuraminidase inhibitor solution for intravenous infusion used in the treatment of severe influenza A and B infections
Dectova (zanamivir) is a prescription antiviral medicine administered as an intravenous infusion for the treatment of severe influenza (flu) infections caused by influenza A or B viruses. It belongs to the neuraminidase inhibitor class and is specifically intended for hospitalized patients when other influenza treatments are unsuitable. Dectova may be used in adults and children from 6 months of age.
Quick Facts
Key Takeaways
- Dectova is an intravenous formulation of zanamivir specifically designed for hospitalized patients with severe influenza who cannot take oral or inhaled antivirals.
- Treatment should begin as soon as possible, ideally within 6 days of symptom onset, and typically lasts 5 to 10 days.
- The standard adult dose is 600 mg twice daily, administered as a 30-minute IV infusion; dose reduction is required for patients with impaired kidney function.
- Common side effects include diarrhea, elevated liver enzymes, and skin rash; serious allergic reactions and severe skin reactions are rare but possible.
- Dectova can be used in adults and children from 6 months of age, with dosing determined by the physician based on age, weight, and renal function.
What Is Dectova and What Is It Used For?
Dectova contains the active substance zanamivir, which belongs to a group of medicines called neuraminidase inhibitors. These antiviral agents work by blocking the neuraminidase enzyme on the surface of influenza viruses. Neuraminidase is a glycoprotein enzyme that plays a critical role in the influenza virus life cycle by cleaving sialic acid residues, which allows newly formed viral particles to be released from infected host cells and spread throughout the respiratory tract.
By inhibiting neuraminidase, zanamivir effectively prevents the release and spread of both influenza A and influenza B viruses. Unlike the inhaled form of zanamivir (marketed as Relenza), Dectova is formulated as a solution for intravenous infusion, making it suitable for patients who are too ill to take oral medications or use inhalers. This includes patients who are mechanically ventilated, sedated in intensive care units, or who have impaired gastrointestinal absorption.
Dectova is indicated for the treatment of complicated or potentially life-threatening influenza A or B virus infection in situations where the patient's influenza virus is known or suspected to be resistant to anti-influenza medicinal products other than zanamivir, and/or other anti-influenza medicinal products including inhaled zanamivir are not suitable. It is intended as a hospital-only medicine and is not used for flu prevention (prophylaxis).
The drug was approved by the European Medicines Agency (EMA) under an exceptional circumstances authorization, meaning that due to the rarity of severe influenza requiring IV treatment, it was not possible to obtain complete clinical data through conventional clinical trials. The EMA reviews new information annually and updates the product information as needed.
Dectova is a hospital-only medicine. It cannot be self-administered and must be given by healthcare professionals in a clinical setting. Treatment with Dectova does not replace annual influenza vaccination, which remains the most effective strategy for preventing influenza.
What Should You Know Before Receiving Dectova?
Contraindications
Dectova must not be used if you are allergic (hypersensitive) to zanamivir or any of the other ingredients in this medicine. The other ingredients include sodium chloride and water for injections. If you have a known allergy to any of these substances, inform your healthcare provider immediately so that an alternative treatment can be considered.
There are no absolute contraindications beyond hypersensitivity to the active ingredient or excipients. However, careful clinical judgment is required when initiating treatment, particularly in patients with a history of severe allergic reactions to other neuraminidase inhibitors such as oseltamivir (Tamiflu).
Warnings and Precautions
Several important warnings and precautions should be considered before and during treatment with Dectova:
Serious skin reactions and allergic reactions have been reported following the administration of Dectova. Symptoms may include swelling of the skin or throat, breathing difficulties, skin rash with blisters, or peeling skin. These reactions include erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. If you notice any of these symptoms, tell your doctor or nurse immediately.
During treatment with Dectova, behavioral changes such as confusion and unresponsiveness may occur. Some patients have also experienced hallucinations (seeing, hearing, or feeling things that are not there) or seizures that may lead to loss of consciousness. These symptoms also occur in people with influenza who have not received Dectova, so it is uncertain whether Dectova contributes to their occurrence. Report any such symptoms immediately.
Immunocompromised patients: If your immune system is weakened (immunocompromised), your doctor may monitor you more closely to ensure the treatment is working effectively. Immunocompromised patients may have prolonged viral shedding and there is a theoretical risk of developing zanamivir-resistant influenza strains during treatment. Your physician may consider switching to an alternative treatment if resistance is suspected.
Renal impairment: Since zanamivir is primarily eliminated by the kidneys, patients with reduced kidney function require dose adjustments. Your doctor will order blood tests to assess your kidney function (creatinine clearance) and will adjust the dose accordingly to prevent drug accumulation.
Sodium content: Each vial of Dectova contains 70.8 mg of sodium (the main component of cooking/table salt). This is equivalent to approximately 3.54% of the recommended maximum daily sodium intake for adults. This should be taken into consideration for patients on a controlled sodium diet.
Pregnancy and Breastfeeding
If you are pregnant or breastfeeding, think you may be pregnant, or are planning to have a baby, seek advice from your doctor before receiving this medicine. The decision to use Dectova during pregnancy should be made by weighing the potential benefits of treatment against the potential risks to the unborn child. Limited data are available on the use of zanamivir in pregnant women.
Animal reproductive studies with zanamivir have not shown evidence of teratogenicity (birth defects). However, as with all medicines, the decision to use Dectova during pregnancy should be based on a careful risk-benefit assessment by the treating physician. During a severe or pandemic influenza outbreak, delaying treatment may pose a greater risk to the mother and fetus than the potential risks of the drug itself.
It is not known whether zanamivir passes into breast milk. Your doctor will weigh the benefits of breastfeeding for your baby against the benefits of treatment for you before advising whether you should continue breastfeeding during treatment.
Drug Interactions
Tell your doctor about all medicines you are currently taking, have recently taken, or might take. Although formal drug interaction studies have not been extensively conducted for IV zanamivir, clinically significant pharmacokinetic interactions are considered unlikely based on the drug's pharmacological properties. Zanamivir is not metabolized by cytochrome P450 enzymes and does not inhibit or induce these enzymes, which reduces the likelihood of interactions with other commonly used drugs.
Influenza vaccines: Inactivated influenza vaccines can be administered at any time relative to Dectova treatment. However, live attenuated influenza vaccines (such as the nasal spray flu vaccine) should not be administered within 2 weeks before or 48 hours after zanamivir use, as zanamivir may inhibit replication of the live vaccine virus and reduce its effectiveness.
Driving and operating machinery: Dectova is not expected to affect the ability to drive or use machines. However, given that this medication is administered in a hospital setting to severely ill patients, this is generally not a relevant concern during the treatment period.
How Does Dectova Interact with Other Drugs?
Zanamivir has a low propensity for pharmacokinetic drug interactions. It is not protein bound, is not metabolized by or a substrate for cytochrome P450 (CYP) enzymes, and does not inhibit or induce CYP enzymes. The drug is primarily excreted unchanged by the kidneys via glomerular filtration. Nevertheless, the following interactions should be considered in clinical practice:
| Drug / Class | Interaction Type | Clinical Significance | Recommendation |
|---|---|---|---|
| Live attenuated influenza vaccine (LAIV) | Pharmacodynamic | Moderate | Avoid LAIV within 2 weeks before or 48 hours after zanamivir use |
| Nephrotoxic drugs (e.g., aminoglycosides, vancomycin, amphotericin B) | Pharmacokinetic | Moderate | Monitor renal function closely; dose adjustment of Dectova may be needed |
| Inactivated influenza vaccines | None | None | Can be administered at any time; no interaction expected |
| Probenecid | Pharmacokinetic | Low | Unlikely to be clinically relevant; zanamivir is primarily cleared by glomerular filtration |
| Other neuraminidase inhibitors (e.g., oseltamivir) | Pharmacodynamic | Low | Combination use not generally recommended; no additional benefit expected |
Although clinically significant drug interactions with zanamivir are uncommon, it is important to inform your healthcare team about all medications you are currently receiving, including over-the-counter medicines, herbal supplements, and vitamins. This is especially important in the intensive care setting where multiple drugs are often administered simultaneously.
What Is the Correct Dosage of Dectova?
The dosage of Dectova is determined by your physician based on your age, body weight, and kidney function (as measured by blood tests). Treatment should be initiated as soon as possible, ideally within 6 days from the onset of influenza symptoms. The duration of treatment is typically 5 to 10 days, and the dose may need to be adjusted depending on your response to treatment.
Adults
Standard Adult Dose
The recommended dose for adults with normal kidney function is 600 mg administered intravenously twice daily. Each dose is given as a 30-minute infusion, typically into a vein in the arm. If your kidneys are not functioning as well as they should, your doctor will reduce the dose accordingly.
| Renal Function (CrCl) | Dose | Frequency | Duration |
|---|---|---|---|
| Normal (>80 ml/min) | 600 mg | Twice daily | 5-10 days |
| Mild impairment (50-80 ml/min) | Adjustment may be needed | Twice daily | 5-10 days |
| Moderate impairment (30-49 ml/min) | Reduced dose | As directed | 5-10 days |
| Severe impairment (<30 ml/min) | Significantly reduced | As directed | 5-10 days |
Children (6 Months and Older)
The dose for children is determined by the treating physician based on the child's age, body weight, and kidney function. Children receive weight-based dosing, and the physician will calculate the appropriate volume of Dectova to administer. The same renal function considerations apply to pediatric patients as to adults.
Dectova is not recommended for use in infants younger than 6 months of age due to insufficient safety and efficacy data in this age group. For children who can tolerate oral medication, oral oseltamivir may be considered as a first-line treatment option.
Elderly Patients
No specific dose adjustment is required based on age alone. However, elderly patients are more likely to have reduced kidney function, and the dose should be adjusted according to their measured or estimated creatinine clearance. Elderly patients should also be monitored closely for side effects, particularly hepatotoxicity, given the higher prevalence of comorbid conditions in this population.
How Dectova Is Administered
Dectova is administered exclusively in a hospital setting by trained healthcare professionals. The medication is given as an intravenous infusion (IV drip) over approximately 30 minutes. It may be infused undiluted or diluted in 0.9% sodium chloride solution for injection to a minimum concentration of 0.2 mg/ml. Each vial is for single use only; any remaining solution after use must be discarded.
The infusion is typically given through a peripheral intravenous line in the arm, although central venous access may be used in critically ill patients. Healthcare professionals must use aseptic technique during preparation and administration of the infusion.
Overdose
Overdose with Dectova is unlikely in clinical practice as it is administered by healthcare professionals in a controlled setting. However, if you believe you have received too much Dectova, inform your doctor or nurse immediately. There is no specific antidote for zanamivir overdose. Treatment of overdose would be supportive, with monitoring of clinical status and vital signs. Hemodialysis may be considered for removal of the drug in cases of significant overdose, as zanamivir has low protein binding.
What Are the Side Effects of Dectova?
Like all medicines, Dectova can cause side effects, although not everyone experiences them. Some side effects can be serious and require immediate medical attention. The frequency of side effects is classified according to international conventions:
Common
May affect up to 1 in 10 patients
- Diarrhea
- Hepatocellular injury (liver cell damage)
- Skin rash
- Elevated aminotransferases (liver enzyme levels detected in blood tests)
Uncommon
May affect up to 1 in 100 patients
- Urticaria (hives) — itchy, raised welts on the skin
- Elevated alkaline phosphatase (liver/bone enzyme detected in blood tests)
Frequency Not Known
Cannot be estimated from available data
- Abnormal behavior
- Hallucinations (seeing, hearing, or feeling things that are not there)
- Confused thinking
- Seizures (convulsions)
- Decreased awareness or unresponsiveness
Contact your doctor or nurse immediately if you notice any of the following serious side effects:
- Severe skin reactions: Skin rash with blisters that look like small targets (erythema multiforme), widespread rash with blisters and peeling skin especially around the mouth, nose, eyes, and genitals (Stevens-Johnson syndrome), or extensive skin peeling over large areas of the body (toxic epidermal necrolysis).
- Severe allergic reactions: Itchy rash, swelling of the face, throat, or tongue, breathing difficulties, dizziness, and vomiting.
It is important to note that the neuropsychiatric symptoms (behavioral changes, hallucinations, seizures, decreased awareness) also commonly occur in patients with influenza who have not received any antiviral treatment. Therefore, it is not possible to definitively determine whether these events are caused by Dectova, by the influenza infection itself, or by a combination of both factors.
Liver function monitoring: Because hepatocellular injury and elevated liver enzymes are among the common side effects, your healthcare team will likely monitor your liver function through regular blood tests during the course of treatment. If significant liver abnormalities are detected, your physician may decide to adjust the dose or discontinue the medication.
Reporting Side Effects
Reporting suspected side effects after a medicine has been authorized is important. It allows continued monitoring of the benefit-risk balance of the medicine. Healthcare professionals and patients are encouraged to report any suspected adverse reactions to their national pharmacovigilance authority. In the European Union, side effects can be reported through national reporting systems, which contribute to the EMA's safety monitoring program (EudraVigilance).
How Should You Store Dectova?
As Dectova is a hospital-only medicine, storage is managed by healthcare professionals and hospital pharmacy departments. However, the following storage requirements apply:
- Keep out of sight and reach of children.
- Do not use this medicine after the expiry date stated on the carton and vial after "EXP." The expiry date refers to the last day of that month.
- Store the vials according to the conditions specified by the manufacturer (consult the product packaging for specific temperature requirements).
- Each vial is intended for single use only. Once the seal has been broken, any remaining solution must be discarded.
- If the solution is diluted in 0.9% sodium chloride for infusion, it should be used promptly or stored in a refrigerator and allowed to reach room temperature before administration.
Dectova is a clear, colorless solution for infusion. It is supplied in a 26 ml clear glass vial with a rubber stopper, aluminum seal, and a plastic snap-off cap. Each pack contains 1 vial with 200 mg zanamivir (as hydrate) in 20 ml solution. Do not use if the solution appears discolored, cloudy, or contains visible particles.
What Does Dectova Contain?
Dectova has a simple formulation designed for intravenous use:
| Component | Type | Amount per Vial | Function |
|---|---|---|---|
| Zanamivir (as hydrate) | Active ingredient | 200 mg in 20 ml (10 mg/ml) | Neuraminidase inhibitor — antiviral activity |
| Sodium chloride | Excipient | 70.8 mg sodium per vial | Tonicity agent (isotonicity adjustment) |
| Water for injections | Excipient | To volume (20 ml) | Solvent |
Pharmaceutical form: Dectova is a clear, colorless solution for infusion. It is presented in 26 ml clear glass vials (type I glass) fitted with a bromobutyl rubber stopper, aluminum crimp seal, and a plastic flip-off cap. Each carton contains one vial.
The solution can be administered undiluted or diluted in 0.9% sodium chloride solution for injection. If dilution is required, the final concentration must be at least 0.2 mg/ml. Healthcare professionals should use aseptic technique when preparing the infusion and must discard any unused solution remaining in the vial after a single use.
Marketing Authorization Holder
The marketing authorization for Dectova is held by GlaxoSmithKline Trading Services Limited, based in Dublin, Ireland. The medicine is manufactured by GlaxoSmithKline Manufacturing S.P.A. in Parma, Italy. Dectova has been authorized by the European Medicines Agency (EMA) under the centralized procedure, meaning the authorization is valid across all European Union and European Economic Area member states.
Frequently Asked Questions About Dectova
References
- European Medicines Agency (EMA). Dectova (zanamivir) — Summary of Product Characteristics. Available at: www.ema.europa.eu/en/medicines/human/EPAR/dectova
- World Health Organization (WHO). Guidelines for Pharmacological Management of Pandemic Influenza A(H1N1) 2009 and Other Influenza Viruses. Geneva: WHO; 2010 (Revised 2024).
- Centers for Disease Control and Prevention (CDC). Influenza Antiviral Medications: Summary for Clinicians. Updated 2025. Available at: www.cdc.gov/flu/professionals/antivirals/summary-clinicians.htm
- Marty FM, Vidal-Puigserver J, Clark C, et al. Intravenous zanamivir or oral oseltamivir for hospitalised patients with influenza: an international, randomised, double-blind, double-dummy, phase 3 trial. Lancet Respir Med. 2017;5(2):135-146. doi:10.1016/S2213-2600(16)30435-0
- National Institute for Health and Care Excellence (NICE). Influenza — Diagnosis and Treatment. Clinical Knowledge Summary. Updated 2025.
- Dulek DE, Williams JV, Creech CB, et al. Use of intravenous zanamivir for treatment of severe influenza: a review. Expert Rev Anti Infect Ther. 2020;18(4):313-327.
- British National Formulary (BNF). Zanamivir. Accessed January 2026. Available at: bnf.nice.org.uk
- European Medicines Agency (EMA). Dectova — European Public Assessment Report (EPAR). Procedure No. EMEA/H/C/004452.
Medical Editorial Team
This article was written and medically reviewed by qualified healthcare professionals following international clinical guidelines and peer-reviewed research.
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iMedic Medical Editorial Team — Specialists in Infectious Disease and Clinical Pharmacology
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This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with any questions about a medical condition or medication. Dectova is a prescription medicine that must be administered by healthcare professionals in a hospital setting.