ALBUTEROL

Albuterol tablets contain albuterol sulfate USP, the racemic form of albuterol and a relatively selective beta 2 -adrenergic bronchodilator. Albuterol sulfate has the chemical name α 1 -[( tert -butylamino)methyl]-4-hydroxy- m -xylene- α,α-diol sulfate (2:1) (salt) and the following structural formula: Albuterol sulfate has a molecular weight of 576.7, and the molecular formula is (C 13 H 21 NO 3 ) 2. H 2 SO 4 . Albuterol sulfate, USP is a white or almost white crystalline powder, freely soluble in water, practically insoluble or very slightly soluble in Methylene chloride and alcohol, slightly soluble in Chloroform and Ether. The World Health Organization recommended name for albuterol base is salbutamol. Each albuterol tablet for oral administration contains 2 mg or 4 mg of albuterol as 2.4 mg or 4.8 mg of albuterol sulfate USP, respectively. Each tablet also contains the following inactive ingredients: anhydrous lactose, hypromellose, magnesium stearate and sodium starch glycolate. Structural Formula

Albuterol tablets are indicated for the relief of bronchospasm in adults and children 6 years of age and older with reversible obstructive airway disease.

The following dosages of albuterol tablets are expressed in terms of albuterol base. Usual Dosage Adults and Children Over 12 Years of Age The usual starting dosage for adults and children 12 years and older is 2 or 4 mg three or four times a day. Children 6 to 12 Years of Age The usual starting dosage for children 6 to 12 years of age is 2 mg three or four times a day. Dosage Adjustment Adults and Children Over 12 Years of Age For adults and children 12 years and older, a dosage above 4 mg four times a day should be used only when the patient fails to respond. If a favorable response does not occur with the 4 mg initial dosage, it should be cautiously increased stepwise up to a maximum of 8 mg four times a day as tolerated. Children 6 to 12 Years of Age Who Fail to Respond to the Initial Starting Dosage of 2 mg Four Times a Day For children from 6 to 12 years of age who fail to respond to the initial starting dosage of 2 mg four times a day, the dosage may be cautiously increased stepwise, but not to exceed 24 mg/day (given in divided doses). Elderly Patients and Those Sensitive to Beta-adrenergic Stimulators An initial dosage of 2 mg three or four times a day is recommended for elderly patients and for those with a history of unusual sensitivity to beta-adrenergic stimulators. If adequate bronchodilation is not obtained, dosage may be increased gradually to as much as 8 mg three or four times a day. The total daily dose should not exceed 32 mg in adults and children 12 years and older.

Albuterol tablets are contraindicated in patients with a history of hypersensitivity to albuterol, or any of its components.

In clinical trials, the most frequent adverse reactions to albuterol tablets were: Percent Incidence of Adverse Reactions Reaction Percent Incidence Central nervous system Nervousness 20% Tremor 20% Headache 7% Sleeplessness 2% Weakness 2% Dizziness 2% Drowsiness <1% Restlessness <1% Irritability <1% Cardiovascular Tachycardia 5% Palpitations 5% Chest discomfort <1% Flushing <1% Musculoskeletal Muscle cramps 3% Gastrointestinal Nausea 2% Genitourinary Difficulty in micturition <1% Rare cases of urticaria, angioedema, rash, bronchospasm, and oropharyngeal edema have been reported after the use of albuterol. In addition, albuterol, like other sympathomimetic agents, can cause adverse reactions such as hypertension, angina, vomiting, vertigo, central nervous system stimulation, unusual taste, and drying or irritation of the oropharynx. The reactions are generally transient in nature, and it is usually not necessary to discontinue treatment with albuterol tablets. In selected cases, however, dosage may be reduced temporarily; after the reaction has subsided, dosage should be increased in small increments to the optimal dosage.

The concomitant use of albuterol and other oral sympathomimetic agents is not recommended since such combined use may lead to deleterious cardiovascular effects. This recommendation does not preclude the judicious use of an aerosol bronchodilator of the adrenergic stimulant type in patients receiving albuterol. Such concomitant use, however, should be individualized and not given on a routine basis. If regular coadministration is required, then alternative therapy should be considered. Monamine Oxidase Inhibitors or Tricyclic Antidepressants Albuterol 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 albuterol 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 albuterol, 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 ECG changes and/or hypokalemia that may result from the administration of nonpotassium-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 nonpotassium-sparing diuretics. Digoxin Mean decreases of 16% to 22% in serum digoxin levels were demonstrated after single-dose intravenous and oral administration of albuterol, respectively, to normal volunteers who had received digoxin for 10 days. The clinical significance of these findings for patients with obstructive airway disease who are receiving albuterol and digoxin on a chronic basis is unclear. Nevertheless, it would be prudent to carefully evaluate the serum digoxin levels in patients who are currently receiving digoxin and albuterol.