Zanamivir Side Effects

Brand Names: Relenza

Please note - some side effects for Zanamivir may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Side Effects of Zanamivir - for the Consumer

Zanamivir

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Zanamivir:

Cough; diarrhea; dizziness; headache; nausea; sinus inflammation; sore throat; stuffy nose; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, throat, or tongue); abnormal behavior; confusion; hallucinations; irregular heartbeat; mood or mental changes; rash with fever, mouth sores, or red and irritated eyes; red, swollen, blistered, or peeling skin; seizures; shortness of breath; symptoms of infection (eg, fever, chills, persistent sore throat); trouble swallowing; wheezing.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

Side Effects by Body System - for Healthcare Professionals

General

Zanamivir is generally well-tolerated. In clinical trials, the incidence of adverse events in patients treated with zanamivir was similar to that in the placebo (lactose vehicle) group.

Respiratory

In a Phase I study, bronchospasm was reported in 1 of 13 patients with mild or moderate asthma following the administration of zanamivir. In a Phase III study of patients with acute influenza-like illness and underlying asthma or chronic obstructive pulmonary disease, more patients on zanamivir (10%) than on placebo (9%) experienced greater than 20% decline in FEV1 after 5 days of treatment.

Respiratory side effects have included cough (up to 17%), viral respiratory infections (up to 13%), nasal signs and symptoms (up to 12%), sinusitis (up to 3%), bronchitis (2%), ear, nose and throat infections (up to 2%), nasal inflammation (1%), decline in FEV1, congestion, rhinitis, and dry throat. Asthma, exacerbation of asthma, bronchospasm, respiratory arrest, dyspnea, lung tightness, and/or decline in lung function may occur in patients with underlying respiratory disease treated with zanamivir. Bronchospasm and dyspnea have been reported during postmarketing experience.

Nervous system

Nervous system side effects have included headache (up to 24%) and dizziness (up to 2%). Seizures, syncope, and vasovagal-like episodes shortly after inhalation have been reported during postmarketing experience.

Other

Other side effects have included throat and tonsil discomfort and pain (up to 19%), malaise (up to 8%), fatigue (up to 8%), temperature regulation disturbances (fever and/or chills; up to 9%), and abdominal pain in less than 1.5% of patients. Facial edema has been reported during postmarketing experience.

Musculoskeletal

Musculoskeletal side effects have included muscle pain (up to 8%), musculoskeletal pain (6%), arthralgia and articular rheumatism (up to 2%), and myalgia (less than 1.5%).

Dermatologic

Dermatologic side effects have included urticaria in less than 1.5% of patients. Rash, including serious cutaneous reactions (e.g., erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis), and urticaria have been reported during postmarketing experience.

Hypersensitivity

Hypersensitivity side effects have included allergic or allergic-like reactions, including oropharyngeal edema, serious skin rashes, and anaphylaxis during postmarketing experience.

Psychiatric

Psychiatric side effects have included delirium, including symptoms such as altered level of consciousness, confusion, abnormal behavior, delusions, hallucinations, agitation, anxiety, nightmares, during postmarketing experience.

Abnormal behavior and delirium leading to injury, with fatal outcomes in some cases, with the use of zanamivir in influenza patients have been reported. Although frequency is unknown, based on zanamivir usage, these events appear to be uncommon. These events were primarily reported in pediatric patients and often had an abrupt onset and rapid resolution. Since influenza may be associated with neurologic and behavioral symptoms (including hallucinations, delirium, and abnormal behavior, with fatal outcomes in some cases), zanamivir's contribution to these events has not been established.

Gastrointestinal

Gastrointestinal side effects have included diarrhea (up to 3%), nausea (up to 3%), and vomiting (up to 2%).

Metabolic

Metabolic side effects have included feeding problems (decreased or increased appetite and anorexia; up to 4%) and elevated creatine phosphokinase.

Hepatic

Hepatic side effects have included elevated liver enzymes.

Hematologic

Hematologic side effects have included lymphopenia and neutropenia.

Cardiovascular

Cardiovascular side effects have included arrhythmias during postmarketing experience.

Renal

Renal side effects have included one case report acute renal failure, increased serum creatinine, hyperkalemia, and hypotension in a patient with multiple medical problems and multiple other medications.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This information does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of information provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.