Arformoterol

Other adrenergic drugs may potentiate effect. Use with caution. (5.3, 7.1) Xanthine derivatives, steroids, diuretics, or non-potassium sparing diuretics may potentiate hypokalemia or ECG changes. Use with caution. (5.7, 7.2, 7.3) MAO inhibitors, tricyclic antidepressants and drugs that prolong the QTc interval may potentiate effect on the cardiovascular system. Use with extreme caution. (7.4) Beta-blockers may decrease effectiveness. May block bronchodilatory effects of beta-agonists. Use with caution and only when medically necessary. (7.5)

7.1 Adrenergic Drugs If additional adrenergic drugs are to be administered by any route, they should be used with caution because the sympathetic effects of arformoterol may be potentiated [see Warnings and Precautions (5.3, 5.5, 5.6, 5.7)] .

7.2 Xanthine Derivatives, Steroids or Diuretics Concomitant treatment with methylxanthine (aminophylline, theophylline), steroids, or diuretics may potentiate any hypokalemic effect of adrenergic agonists including arformoterol tartrate inhalation solution [see Warnings and Precautions (5.7)]. The concurrent use of intravenously or orally administered methylxanthines (e.g., aminophylline, theophylline) by patients receiving arformoterol tartrate inhalation solution has not been completely evaluated.

In two combined 12-week, placebo-controlled trials that included arformoterol tartrate inhalation solution doses of 15 mcg twice daily, 25 mcg twice daily, and 50 mcg once daily, 54 of 873 arformoterol tartrate inhalation solution-treated subjects received concomitant theophylline at study entry. In a 12-month controlled trial that included a 50 mcg once daily arformoterol tartrate inhalation solution dose, 30 of the 528 arformoterol tartrate inhalation solution-treated subjects received concomitant theophylline at study entry.

In these trials, heart rate and systolic blood pressure were approximately 2 to 3 bpm and 6 to 8 mm Hg higher, respectively, in subjects on concomitant theophylline compared with the overall population.

7.3 Non-potassium Sparing Diuretics The ECG 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, including arformoterol tartrate inhalation solution, with non-potassium sparing diuretics.

7.4 MAO Inhibitors, Tricyclic Antidepressants, QTc Prolonging Drugs Arformoterol tartrate inhalation solution, as with other beta-agonists, should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors, tricyclic antidepressants, or drugs known to prolong the QTc interval because of the effect of adrenergic agonists on the cardiovascular system may be potentiated by these agents. Drugs that are known to prolong the QT c interval have an increased risk of ventricular arrhythmias.

7.5 Beta-Blockers Beta-adrenergic receptor antagonists (beta-blockers) and arformoterol tartrate inhalation solution may inhibit the effect of each other when administered concurrently. Beta-blockers not only block the therapeutic effects of beta-agonists, but may produce severe bronchospasm in COPD patients. Therefore, patients with COPD 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-blockers in patients with COPD. In this setting, cardioselective beta-blockers could be considered, although they should be administered with caution.

8.1 Pregnancy Risk Summary There are no adequate and well-controlled studies in pregnant women. Arformoterol tartrate should only be used during pregnancy if the expected benefit to the patient outweighs the potential risk to the fetus. Women should be advised to contact their physician if they become pregnant while taking arformoterol tartrate.

In animal reproduction studies with arformoterol administered by the oral route to rats and rabbits at exposures approximately 370 and 8,400 times the adult exposure at the maximum recommended human daily inhalation dose (MRHDID) of 15 mcg every 12 hours, respectively, there were findings of structural abnormalities, embryofetal and infant mortality, and alterations of growth. These adverse effects generally occurred at large multiples of the MRHDID when arformoterol was administered by the oral route to achieve high systemic exposures. No evidence of fetal harm was observed in rabbits at an exposure approximately 4,900 times the MRHDID.

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Labor or Delivery: The potential effect of arformoterol tartrate on labor and delivery is unknown. Because of the potential for beta-agonists interference with uterine contractility, use of arformoterol tartrate inhalation solution during labor should be restricted to whom the benefits clearly outweigh the risk.

Data Animal Data In an embryofetal development study in which pregnant rats received doses of 1,000, 5,000 or 10,000 mcg/kg/day from gestation days 6 to 17, arformoterol was shown to be teratogenic based upon findings of omphalocele (umbilical hernia), a malformation, in rat fetuses at exposures approximately 370 times adult exposure at the MRHDID (on an AUC basis with maternal oral doses of 1,000 mcg/kg/day and higher. Maternal toxicity was not observed in rats with exposures up to 2,400 times the MRHDID (on an AUC basis with maternal oral doses up to 10,000 mcg/kg/day). A no-observed-adverse-effect-level (NOAEL) for rat fetuses was not identified.

In an embryofetal development study in which pregnant rabbits received doses of 20,000, 40,000 or 80,000 mcg/kg/day from gestation days 7 to 20, arformoterol was shown to be teratogenic based upon findings of malpositioned right kidney, a malformation, in rabbit fetuses at exposures approximately 8400 times and higher…