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Relenza

"The U.S. Food and Drug Administration today approved the first adjuvanted vaccine for the prevention of H5N1 influenza, commonly known as avian or bird flu. The vaccine, Influenza A (H5N1) Virus Monovalent Vaccine, Adjuvanted, is for use in peopl"...

Relenza

Relenza Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Relenza (zanamivir) Inhalation Powder is used to treat flu symptoms caused by influenza virus in patients who have had symptoms for less than 2 days. It may also be given to prevent influenza in people who may be exposed but do not yet have symptoms. It will not treat the common cold. It is an antiviral medication. Common side effects include dizziness, or, because this medication is an inhaled powder, increased coughing after using it.

The recommended dose of Relenza for treatment of influenza in adults and pediatric patients aged 7 years and older is 10 mg twice daily (approximately 12 hours apart) for 5 days. Other drugs may interact with Relenza. Tell your doctor all medications and supplements you use. During pregnancy, Relenza should be used only when prescribed. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Our Relenza (zanamivir) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is Patient Information in Detail?

Easy-to-read and understand detailed drug information and pill images for the patient or caregiver from Cerner Multum.

Relenza in Detail - Patient Information: Side Effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Some people using zanamivir have had rare side effects of confusion, delirium and self-injury. These symptoms have occurred most often in children. It is not known whether zanamivir was the exact cause of these symptoms. However, anyone using zanamivir should be watched closely for signs of confusion or unusual behavior. Call a doctor at once if you or the child using zanamivir has any of these symptoms.

Stop using zanamivir and call your doctor at once if you have wheezing or severe breathing problems, or if you feel like you might pass out.

Less serious side effects may include:

  • headache;
  • dizziness;
  • nausea, vomiting, diarrhea;
  • fever, chills, joint pain;
  • ear pain; or
  • cold symptoms such as stuffy nose, sneezing, sore throat;

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Relenza (Zanamivir) »

What is Patient Information Overview?

A concise overview of the drug for the patient or caregiver from First DataBank.

Relenza Overview - Patient Information: Side Effects

SIDE EFFECTS: Dizziness may occur. Also, because this medication is an inhaled powder, you may experience increased coughing after using it. If either of these effects persists or worsens, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication can cause breathing problems, which in rare cases can be fatal. If you experience trouble breathing such as wheezing or shortness of breath, stop using zanamivir and get medical help right away. Zanamivir is not recommended if you have lung/breathing problems. Discuss the risks and benefits with your doctor. However, if your doctor decides you should use zanamivir, have a quick-relief inhaled bronchodilator (such as albuterol inhaler) readily available.

The flu itself or zanamivir may rarely cause serious mental/mood changes. This may be more likely in children. Tell your doctor right away of any signs of unusual behavior, including confusion, agitation, self-injury.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the entire patient information overview for Relenza (Zanamivir)»

What is Prescribing information?

The FDA package insert formatted in easy-to-find categories for health professionals and clinicians.

Relenza FDA Prescribing Information: Side Effects
(Adverse Reactions)

SIDE EFFECTS

See WARNINGS AND PRECAUTIONS for information about risk of serious adverse events such as bronchospasm and allergic-like reactions, and for safety information in patients with underlying airways disease.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The placebo used in clinical studies consisted of inhaled lactose powder, which is also the vehicle for the active drug; therefore, some adverse events occurring at similar frequencies in different treatment groups could be related to lactose vehicle inhalation.

Treatment of Influenza

Clinical Trials in Adults and Adolescents: Adverse events that occurred with an incidence ≥ 1.5% in treatment studies are listed in Table 1. This table shows adverse events occurring in patients aged ≥ 12 years receiving RELENZA 10 mg inhaled twice daily, RELENZA in all inhalation regimens, and placebo inhaled twice daily (where placebo consisted of the same lactose vehicle used in RELENZA).

Table 1. Summary of Adverse Events ≥ 1.5% Incidence During Treatment in Adults and Adolescents

Adverse Event RELENZA Placebo
(Lactose Vehicle)
(n= 1,520)
10 mg b.i.d. Inhaled
(n= 1,132)
All Dosing Regimensa
(n = 2,289)
Body as a whole
  Headaches 2% 2% 3%
Digestive
  Diarrhea 3% 3% 4%
  Nausea 3% 3% 3%
  Vomiting 1% 1% 2%
Respiratory
  Nasal signs and symptoms 2% 3% 3%
  Bronchitis 2% 2% 3%
  Cough 2% 2% 3%
  Sinusitis 3% 2% 2%
  Ear, nose, and throat infections 2% 1% 2%
Nervous system
  Dizziness 2% 1% < 1%
a Includes studies where RELENZA was administered intranasally (6.4 mg 2 to 4 times per day in addition to inhaled preparation) and/or inhaled more frequently (q.i.d.) than the currently recommended dose.

Additional adverse reactions occurring in less than 1.5% of patients receiving RELENZA included malaise, fatigue, fever, abdominal pain, myalgia, arthralgia, and urticaria.

The most frequent laboratory abnormalities in Phase III treatment studies included elevations of liver enzymes and CPK, lymphopenia, and neutropenia. These were reported in similar proportions of zanamivir and lactose vehicle placebo recipients with acute influenza-like illness.

Clinical Trials in Pediatric Patients: Adverse events that occurred with an incidence ≥ 1.5% in children receiving treatment doses of RELENZA in 2 Phase III studies are listed in Table 2. This table shows adverse events occurring in pediatric patients aged 5 to 12 years receiving RELENZA 10 mg inhaled twice daily and placebo inhaled twice daily (where placebo consisted of the same lactose vehicle used in RELENZA).

Table 2. Summary of Adverse Events ≥ 1.5% Incidence During Treatment in Pediatric Patientsa

Adverse Event RELENZA
10 mg b.i.d. Inhaled
(n = 291)
Placebo
(Lactose Vehicle)
(n = 318)
Respiratory
  Ear, nose, and throat infections 5% 5%
  Ear, nose, and throat hemorrhage < 1% 2%
  Asthma < 1% 2%
  Cough < 1% 2%
Digestive
  Vomiting 2% 3%
  Diarrhea 2% 2%
  Nausea < 1% 2%
a Includes a subset of patients receiving RELENZA for treatment of influenza in a prophylaxis study.

In 1 of the 2 studies described in Table 2, some additional information is available from children (aged 5 to 12 years) without acute influenza-like illness who received an investigational prophylaxis regimen of RELENZA; 132 children received RELENZA and 145 children received placebo. Among these children, nasal signs and symptoms (zanamivir 20%, placebo 9%), cough (zanamivir 16%, placebo 8%), and throat/tonsil discomfort and pain (zanamivir 11%, placebo 6%) were reported more frequently with RELENZA than placebo. In a subset with chronic pulmonary disease, lower respiratory adverse events (described as asthma, cough, or viral respiratory infections which could include influenza-like symptoms) were reported in 7 of 7 zanamivir recipients and 5 of 12 placebo recipients.

Prophylaxis of Influenza

Family/Household Prophylaxis Studies: Adverse events that occurred with an incidence of ≥ 1.5% in the 2 prophylaxis studies are listed in Table 3. This table shows adverse events occurring in patients aged ≥ 5 years receiving RELENZA 10 mg inhaled once daily for 10 days.

Table 3. Summary of Adverse Events ≥ 1.5% Incidence During 10-Day Prophylaxis Studies in Adults. Adolescents, and Childrena

Adverse Event Contact Cases
RELENZA
(n= 1,068)
Placebo
(n= 1,059)
Lower respiratory
  Viral respiratory infections 13% 19%
  Cough 7% 9%
Neurologic
  Headaches 13% 14%
Ear, nose, and throat
  Nasal signs and symptoms 12% 12%
  Throat and tonsil discomfort and pain 8% 9%
  Nasal inflammation 1% 2%
Musculoskeletal
  Muscle pain 3% 3%
Endocrine and metabolic
  Feeding problems (decreased or increased appetite and anorexia) 2% 2%
Gastrointestinal
  Nausea and vomiting 1% 2%
Non-site specific
  Malaise and fatigue 5% 5%
  Temperature regulation disturbances (fever and/or chills) 5% 4%
a In prophylaxis studies, symptoms associated with influenza-like illness were captured as adverse events; subjects were enrolled during a winter respiratory season during which time any symptoms that occurred were captured as adverse events.

Community Prophylaxis Studies: Adverse events that occurred with an incidence of ≥ 1.5% in 2 prophylaxis studies are listed in Table 4. This table shows adverse events occurring in patients aged ≥ 5 years receiving RELENZA 10 mg inhaled once daily for 28 days.

Table 4. Summary of Adverse Events ≥ 1.5% Incidence During 28-Day Prophylaxis Studies in Adults, Adolescents, and Childrena

Adverse Event RELENZA
(n = 2,231)
Placebo
(n = 2,239)
Neurologic
  Headaches 24% 26%
Ear, nose, and throat
  Throat and tonsil discomfort and pain 19% 20%
  Nasal signs and symptoms 12% 13%
  Ear, nose, and throat infections 2% 2%
Lower respiratory
  Cough 17% 18%
  Viral respiratory infections 3% 4%
Musculoskeletal
  Muscle pain 8% 8%
  Musculoskeletal pain 6% 6%
  Arthralgia and articular rheumatism 2% < 1%
Endocrine and metabolic
  Feeding problems (decreased or increased appetite and anorexia) 4% 4%
Gastrointestinal
  Nausea and vomiting 2% 3%
  Diarrhea 2% 2%
Non-site specific
  Temperature regulation disturbances (fever and/or chills) 9% 10%
  Malaise and fatigue 8% 8%
a In prophylaxis studies, symptoms associated with influenza-like illness were captured as adverse events; subjects were enrolled during a winter respiratory season during which time any symptoms that occurred were captured as adverse events.

Postmarketing Experience

In addition to adverse events reported from clinical trials, the following events have been identified during postmarketing use of zanamivir (RELENZA). Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to zanamivir (RELENZA).

Allergic Reactions: Allergic or allergic-like reaction, including oropharyngeal edema [see WARNINGS AND PRECAUTIONS].

Psychiatric: Delirium, including symptoms such as altered level of consciousness, confusion, abnormal behavior, delusions, hallucinations, agitation, anxiety, nightmares [see WARNINGS AND PRECAUTIONS].

Cardiac: Arrhythmias, syncope.

Neurologic: Seizures. Vasovagal-like episodes have been reported shortly following inhalation of zanamivir.

Respiratory: Bronchospasm, dyspnea [see WARNINGS AND PRECAUTIONS].

Skin: Facial edema; rash, including serious cutaneous reactions (e.g., erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis); urticaria [see WARNINGS AND PRECAUTIONS].

Read the entire FDA prescribing information for Relenza (Zanamivir) »

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Relenza - User Reviews

Relenza User Reviews

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Here is a collection of user reviews for the medication Relenza sorted by most helpful. Patient Discussions FAQs

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