Cardiovascular

MAXAIR AUTOHALER, like other inhaled beta adrenergic agonists, can produce a clinically significant cardiovascular effect in some patients, as measured by pulse rate, blood pressure and/or symptoms. Although such effects are uncommon after administration of MAXAIR AUTOHALER at recommended doses, if they occur, the drug may need to be discontinued. In addition, beta-agonists have been reported to produce ECG changes, such as flattening of the T wave, prolongation of the QT interval, and ST segment depression. The clinical significance of these findings is unknown. Therefore, MAXAIR AUTOHALER, like all sympathomimetic amines, should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, cardiac arrhythmias, and hypertension.

Paradoxical Bronchospasm

MAXAIR AUTOHALER can produce paradoxical bronchospasm, which can be life threatening. If paradoxical bronchospasm occurs, MAXAIR AUTOHALER should be discontinued immediately and alternative therapy instituted. It should be recognized that paradoxical bronchospasm, when associated with inhaled formulations, frequently occurs with the first use of a new canister or vial.

Use of Anti-Inflammatory Agents

The use of beta adrenergic agonist bronchodilators alone may not be adequate to control asthma in many patients. Early consideration should be given to adding anti-inflammatory agents, e.g., corticosteroids.

Deterioration of Asthma

Asthma may deteriorate acutely over a period of hours or chronically over several days or longer. If the patient needs more doses of MAXAIR AUTOHALER than usual, this may be a marker of destabilization of asthma and requires reevaluation of the patient and the treatment regimen, giving special consideration to the possible need for anti-inflammatory treatment, e.g., corticosteroids.

General

Since pirbuterol is a sympathomimetic amine, it should be used with caution in patients with cardiovascular disorders, including ischemic heart disease, hypertension, or cardiac arrhythmias, in patients with hyperthyroidism or diabetes mellitus, and in patients who are unusually responsive to sympathomimetic amines or who have convulsive disorders. Significant changes in systolic and diastolic blood pressure could be expected to occur in some patients after use of any beta adrenergic aerosol bronchodilator. Beta adrenergic agonist medications may produce significant hypokalemia in some patients, possibly through intracellular shunting, which has the potential to produce adverse cardiovascular effects. The decrease is usually transient, not requiring supplementation.

Information for Patients

The action of MAXAIR AUTOHALER should last up to five hours or longer. MAXAIR AUTOHALER should not be used more frequently than recommended. Do not increase the dose or frequency of MAXAIR AUTOHALER without consulting your physician. If you find that treatment with MAXAIR AUTOHALER becomes less effective for symptomatic relief, or your symptoms become worse, and/or you need to use the product more frequently than usual, you should seek medical attention immediately. While you are using MAXAIR AUTOHALER, other inhaled drugs and asthma medications should be taken only as directed by your physician. Common adverse effects include palpitations, chest pain, rapid heart rate, tremor or nervousness. If you are pregnant or nursing, contact your physician about use of MAXAIR AUTOHALER. Effective and safe use includes an understanding of the way the medication should be administered. (See PATIENT INFORMATION). The MAXAIR AUTOHALER actuator should not be used with any other inhalation aerosol canister. In addition, canisters for use with MAXAIR AUTOHALER should not be utilized with any other actuator.

Drug Interactions

Other short-acting beta adrenergic aerosol bronchodilators should not be used concomitantly with MAXAIR AUTOHALER because they may have additive effects.

Monoamine Oxidase Inhibitors or Tricyclic Antidepressants

Pirbuterol should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants, or within 2 weeks of discontinuation of such agents, because the action of pirbuterol on the vascular system may be potentiated.

Beta Blockers

Beta adrenergic receptor blocking agents not only block the pulmonary effect of beta-agonists, such as MAXAIR AUTOHALER, but may produce severe bronchospasm in asthmatic patients. Therefore, patients with asthma should not normally be treated with beta blockers. However, under certain circumstances, e.g., as prophylaxis after myocardial infarction, there may be no acceptable alternatives to the use of beta adrenergic blocking agents in patients with asthma. In this setting, cardioselective beta blockers could be considered, although they should be administered with caution.

Diuretics

The EGG changes and/or hypokalemia that may result from the administration of non-potassium sparing diuretics (such as loop or thiazide diuretics) can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is not known, caution is advised in the coadministration of beta-agonists with non-potassium sparing diuretics.

Carcinogenesis, Mutagenesis and Impairment of Fertility

In a 2-year study in Sprague-Dawley rats, pirbuterol hydrochloride administered at dietary doses of 1 .0, 3.0, and 10 mg/kg (approximately 3, 10, and 35 times the maximum recommended daily inhalation dose for adults and children on a mg/m² basis) showed no evidence of carcinogenicity. In an 18-month study in mice at dietary doses of 1 .0, 3.0, and 10 mg/kg (approximately 2, 5, and 15 times the maximum recommended daily inhalation dose for adults and children on a mg/m² basis) no evidence of tumorigenicity was seen. Reproduction studies in rats administered pirbuterol hydrochloride at oral doses of 1, 3, and 10 mg/kg (approximately 3, 10, and 35 times the maximum recommended daily inhalation dose for adults on a mg/m² basis) revealed no evidence of impaired fertility. Pirbuterol dihydrochloride showed no evidence of mutagenicity in in vitro assays and host-mediated microbial (Ames) assays for point mutations and in vivo tests for somatic or germ cell effects following acute and subchronic treatment in mice (cytogenicity assays).

Teratogenic Effects † Pregnancy Category C

Pirbuterol was not teratogenic in rats administered oral doses of 30, 100, and 300 mg/kg (approximately 100, 340, and 1,000 times the maximum recommended daily inhalation dose for adults on a mg/m² basis). Pirbuterol was not teratogenic in rabbits administered oral doses of 30 and 100 mg/kg (approximately 200 and 680 times the maximum recommended inhalation dose for adults on a mg/m2 basis). However, pirbuterol at an oral dose of 300 mg/kg (approximately 2,000 times the maximum recommended daily inhalation dose in adults on a mg/m² basis) caused abortions and fetal death. There are no adequate and well-controlled studies in pregnant women. Pirbuterol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Labor and Delivery

Because of the potential for beta-agonist interference with uterine contractility, use of MAXAIR AUTOHALER for relief of bronchospasm during labor should be restricted to those patients in whom the benefits clearly outweigh the risk.

Nursing Mothers

It is not known whether pirbuterol is excreted in human milk. Therefore, MAXAIR AUTOHALER should be used during nursing only if the potential benefit justifies the possible risk to the newborn.

Pediatric Use

MAXAIR AUTOHALER is not recommended for patients under the age of 12 years because of insufficient clinical data to establish safety and effectiveness.

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