Maxair Information
Maxair (Pirbuterol)
Maxair (Pirbuterol) Description
The active component of Maxair (Pirbuterol) AUTOHALER (pirbuterol acetate) is (R,S)α-{[(1,1-dimethylethyl)amino]methyl}-3-hydroxy-2,6-pyridinedimethanol monoacetate salt, a beta-2 adrenergic bronchodilator, having the following chemical structure:
Pirbuterol acetate is a white, crystalline racemic mixture of two optically active isomers. It is a powder, freely soluble in water, with a molecular weight of 300.3 and empirical formula of CHNO•CHO.
Maxair (Pirbuterol) AUTOHALER is a pressurized metered-dose aerosol unit for oral inhalation. It provides a fine-particle suspension of pirbuterol acetate in the propellant mixture of trichloromonofluoromethane and dichlorodifluoromethane, with sorbitan trioleate. Each actuation delivers 253 mcg of pirbuterol (as pirbuterol acetate) from the valve and 200 mcg of pirbuterol (as pirbuterol acetate) from the mouthpiece. The unit is breath-actuated such that the medication is delivered automatically during inspiration without the need for the patient to coordinate actuation with inspiration. Each 14.0 g canister provides 400 inhalations and each 2.8 g canister provides 80 inhalations.
As with all aerosol medications, it is recommended to prime (test) Maxair (Pirbuterol) AUTOHALER before using for the first time. Maxair (Pirbuterol) AUTOHALER should also be primed if it has not been used in 48 hours. As described in the priming procedure, use the test fire slide to release two priming sprays into the air away from yourself and other people. (See portion of this package insert.)
Maxair (Pirbuterol) Clinical Pharmacology
The pharmacologic effects of beta adrenergic agonist drugs, including pirbuterol, are at least in part attributable to stimulation through beta adrenergic receptors of intracellular adenyl cyclase, the enzyme which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3′,5′-adenosine monophosphate (c-AMP). Increased c-AMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells.
Bronchodilator activity of pirbuterol was manifested clinically by an improvement in various pulmonary function parameters (FEV, MMF, PEFR, airway resistance [RAW] and conductance [GA/V]).
Maxair (Pirbuterol) Indications And Usage
Maxair (Pirbuterol) AUTOHALER is indicated for the prevention and reversal of bronchospasm in patients 12 years of age and older with reversible bronchospasm including asthma. It may be used with or without concurrent theophylline and/or corticosteroid therapy.
Maxair (Pirbuterol) Contraindications
Maxair (Pirbuterol) AUTOHALER is contraindicated in patients with a history of hypersensitivity to pirbuterol or any of its ingredients.
Maxair (Pirbuterol) Warnings
Cardiovascular:
Paradoxical Bronchospasm:
Use of Anti-Inflammatory Agents:
Deterioration of Asthma:
Maxair (Pirbuterol) Precautions
General:
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:
“Patient's Instructions For Use”
Drug Interactions:
Monoamine Oxidase Inhibitors or Tricyclic Antidepressants:
Beta Blockers:
Diuretics:
Carcinogenesis, Mutagenesis and Impairment of Fertility:
Pirbuterol dihydrochloride showed no evidence of mutagenicity in assays and host-mediated microbial (Ames) assays for point mutations and tests for somatic or germ cell effects following acute and subchronic treatment in mice (cytogenicity assays).
Teratogenic Effects – Pregnancy Category C:
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:
Nursing Mothers:
Pediatric Use:
Maxair (Pirbuterol) Adverse Reactions
The following rates of adverse reactions to pirbuterol are based on single- and multiple-dose clinical trials involving 761 patients, 400 of whom received multiple doses (mean duration of treatment was 2.5 months and maximum was 19 months).
The following were the adverse reactions reported more frequently than 1 in 100 patients:
The following adverse reactions occurred less frequently than 1 in 100 patients and there may be a causal relationship with pirbuterol:
Other adverse reactions were reported with a frequency of less than 1 in 100 patients but a causal relationship between pirbuterol and the reaction could not be determined: migraine, productive cough, wheezing, and dermatitis.
The following rates of adverse reactions during three-month controlled clinical trials involving 310 patients are noted. The table does not include mild reactions.
Maxair (Pirbuterol) Overdosage
The expected symptoms with overdosage are those of excessive beta-stimulation and/or any of the symptoms listed under , e.g., seizures, angina, hypertension or hypotension, tachycardia with rates up to 200 beats per minute, arrhythmias, nervousness, headache, tremor, dry mouth, palpitation, nausea, dizziness, fatigue, malaise, and insomnia. Hypokalemia may also occur. As with all sympathomimetic aerosol medication, cardiac arrest and even death may be associated with abuse of Maxair (Pirbuterol) AUTOHALER.
Treatment consists of discontinuation of pirbuterol together with appropriate symptomatic therapy. The judicious use of a cardioselective beta-receptor blocker may be considered, bearing in mind that such medication can produce bronchospasm. There is insufficient evidence to determine if dialysis is beneficial for overdosage.
The oral median lethal dose of pirbuterol dihydrochloride in mice and rats is greater than 2000 mg/kg (approximately 3400 and 6800 times the maximum recommended daily inhalation dose for adults on a mg/m basis).
Maxair (Pirbuterol) Dosage And Administration
The usual dose for adults and children 12 years and older is two inhalations (400 mcg) repeated every 4-6 hours. One inhalation (200 mcg) repeated every 4-6 hours may be sufficient for some patients.
A total daily dose of 12 inhalations should not be exceeded.
If a previously effective dosage regimen fails to provide the usual relief, medical advice should be sought immediately as this is often a sign of seriously worsening asthma which would require reassessment of therapy.
Maxair (Pirbuterol) How Supplied
Maxair (Pirbuterol) AUTOHALER, box of one, is supplied in a pressurized aluminum canister with a light blue plastic breath-activated actuator and a light blue mouthpiece cover. DO NOT USE WITH OTHER CANISTERS OR MOUTHPIECES. Each actuation delivers 253 mcg of pirbuterol (as pirbuterol acetate) from the valve and 200 mcg of pirbuterol (as pirbuterol acetate) from the mouthpiece.
Canister net content weight 14.0 g, 400 inhalations (NDC ) and canister net content weight 2.8 g, 80 inhalations (Hospital Pack: NDC , Sample Pack: NDC ).
The correct amount of medication in each canister cannot be assured after 80 actuations from the 2.8 g canister and 400 actuations from the 14.0 g canister, even though the canister is not completely empty. The canister should be discarded when the labeled numbers of actuations have been used.
A notice similar to the above WARNING has been placed in the “Patient's Instructions For Use” portion of this package insert under the Environmental Protection Agency's (EPA's) regulations. The patient's warning states that the patient should consult his or her physician if there are questions about alternatives.
Rx only
Store between 15° and 30°C (59° to 86°F). Failure to use this product within this temperature range may result in improper dosing. For optimal results, the canister should be at room temperature before use. Shake well before using.
The contents of Maxair (Pirbuterol) AUTOHALER are under pressure. Do not puncture. Do not use or store near heat or open flame. Exposure to temperature above 120°F may cause bursting. Never throw container into fire or incinerator. Keep out of reach of children. Avoid spraying in eyes.
The light blue plastic actuator supplied with Maxair (Pirbuterol) AUTOHALER should not be used with any other product canisters, and actuators from other product should not be used with Maxair (Pirbuterol) AUTOHALER canister.
Northridge, CA 91324 3
654800 JULY 2003
Maxair (Pirbuterol)
