ARFORMOTEROL Drug Interactions: What You Need to Know

INTERACTIONS

• 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 co-administration 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 QTc 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.

Arformoterol tartrate inhalation solution is contraindicated in patients with a history of hypersensitivity to arformoterol, racemic formoterol or to any other components of this product. Use of a LABA, including arformoterol tartrate inhalation solution, without an inhaled cortisteroid is contraindicated in patients with asthma [ see Warnings and Precautions (5) ]. Arformoterol tartrate inhalation solution is not indicated for the treatment of asthma.

• Arformoterol tartrate inhalation solution is contraindicated in patients with a history of hypersensitivity to arformoterol, racemic formoterol or to any other components of this product. ( 4 )
• Use of a LABA, including arformoterol tartrate inhalation solution, without an inhaled corticosteroid is contraindicated in patients with asthma. ( 4 )

AND PRECAUTIONS

• LABA as monotherapy (without an inhaled corticosteroid) for asthma increases the risk of serious asthma-related events. ( 5.1 )
• Do not initiate arformoterol tartrate inhalation solution in acutely deteriorating patients. ( 5.2 )
• Do not use for relief of acute symptoms. Concomitant short-acting beta 2 -agonists can be used as needed for acute relief. ( 5.2 )
• Do not exceed the recommended dose. Excessive use of arformoterol tartrate inhalation solution, or use in conjunction with other medications containing long-acting beta 2 -agonists, can result in clinically significant cardiovascular effects, and may be fatal. ( 5.3 , 5.5 )
• Life-threatening paradoxical bronchospasm can occur. Discontinue arformoterol tartrate inhalation solution immediately. ( 5.4 )
• Use with caution in patients with cardiovascular or convulsive disorders, thyrotoxicosis, or with sensitivity to sympathomimetic drugs. ( 5.6 , 5.7 )

5.1 Serious Asthma-Related Events - Hospitalizations, Intubations, Deaths

• The safety and efficacy of arformoterol tartrate inhalation solution in patients with asthma have not been established. Arformoterol tartrate inhalation solution is not indicated for the treatment of asthma [ see Contraindications(4) ].
• Use of long-acting beta 2 -adrenergic agonists (LABA) as monotherapy [without inhaled corticosteroids (ICS)] for asthma is associated with an increased risk of asthma-related death. Available data from controlled clinical trials also suggest that use of LABA as monotherapy increases the risk of asthma-related hospitalization in pediatric and adolescent patients. These findings are considered a class effect of LABA monotherapy. When LABA are used in fixed-dose combination with ICS, data from large clinical trials do not show a significant increase in the risk of serious asthma-related events (hospitalizations, intubations, and death) compared with ICS alone.
• A 28-week, placebo-controlled US study comparing the safety of another LABA (salmeterol) with placebo, each added to usual asthma therapy, showed an increase in asthma-related deaths in patients receiving salmeterol (13/13,176 in patients treated with salmeterol vs. 3/13,179 in patients treated with placebo; RR 4.37, 95% CI 1.25, 15.34). The increased risk of asthma-related death is considered a class effect of the LABA, including arformoterol tartrate inhalation solution.
• No study adequate to determine whether the rate of asthma-related death is increased in patients treated with arformoterol tartrate inhalation solution has been conducted. Clinical studies with racemic formoterol suggested a higher incidence of serious asthma exacerbations in patients who received racemic formoterol than in those who received placebo. The sizes of these studies were not adequate to precisely quantify the differences in serious asthma exacerbation rates between treatment groups.
• Available data do not suggest an increased risk of death with use of LABA in patients with COPD.

5.2 Deterioration of Disease and Acute Episodes Arformoterol tartrate inhalation solution should not be initiated in patients with acutely deteriorating COPD, which may be a life-threatening condition. The use of arformoterol tartrate inhalation solution in this setting is inappropriate. Arformoterol tartrate inhalation solution is not indicated for the treatment of acute episodes of bronchospasm, i.e., as rescue therapy and extra doses should not be used for that purpose. Acute symptoms should be treated with an inhaled short-acting beta 2 -agonist. When beginning arformoterol tartrate inhalation solution, patients who have been taking inhaled short-acting beta 2 -agonists on a regular basis (e.g., four times a day) should be instructed to discontinue the regular use of these drugs and use them only for symptomatic relief of acute respiratory symptoms. When prescribing arformoterol tartrate inhalation solution, the healthcare provider should also prescribe an inhaled, short-acting beta 2 -agonist and instruct the patient how it should be used. Increasing inhaled beta 2 -agonist use is a signal of deteriorating disease for which prompt medical attention is indicated. COPD may deteriorate acutely over a period of hours or chronically over several days or longer. If arformoterol tartrate inhalation solution no longer controls the symptoms of bronchoconstriction, or the patient's inhaled, short-acting beta 2 -agonist becomes less effective or the patient needs more inhalation of short-acting beta 2 -agonist than usual, these may be markers of deterioration of disease. In this setting, a reevaluation of the patient and the COPD treatment regimen should be undertaken at once. Increasing the daily dosage of arformoterol tartrate inhalation solution beyond the recommended 15 mcg twice daily dose is not appropriate in this situation.

5.3 Excessive Use of Arformoterol Tartrate Inhalation Solution and Use with Other Long-Acting Beta 2 -Agonists Fatalities have been reported in association with excessive use of inhaled sympathomimetic drugs. As with other inhaled beta 2 -adrenergic drugs, arformoterol tartrate inhalation solution should not be used more often, at higher doses than recommended, or in conjunction with other medications containing long-acting beta 2 -agonists.

5.4 Paradoxical Bronchospasm As with other inhaled beta 2 -agonists, arformoterol tartrate inhalation solution can produce paradoxical bronchospasm that may be life-threatening. If paradoxical bronchospasm occurs, arformoterol tartrate inhalation solution should be discontinued immediately and alternative therapy instituted.

5.5 Cardiovascular Effects Arformoterol tartrate inhalation solution, like other beta 2 -agonists, can produce a clinically significant cardiovascular effect in some patients as measured by increases in pulse rate, systolic and/or diastolic blood pressure, and/or symptoms. If such effects 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 QTc interval, and ST segment depression. The clinical significance of these findings is unknown. Arformoterol tartrate inhalation solution, as with other sympathomimetic amines, should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, cardiac arrhythmias, and hypertension.

5.6 Coexisting Conditions Arformoterol tartrate inhalation solution, like other sympathomimetic amines, should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, cardiac arrhythmias, and hypertension; in patients with convulsive disorders or thyrotoxicosis, and in patients who are unusually responsive to sympathomimetic amines. In two pooled, 12-week, placebo-controlled trials investigating arformoterol tartrate inhalation solution doses of 15 μg BID, 25 μg BID, and 50 μg QD, changes in mean predose and 2-hour post dose systolic and/or diastolic blood pressure were seen as a general fall of 2 to 4 mm/Hg; for pulse rate the mean of maximal increases were 8.8 to 12.0 beats/min. Over the course of a one-year study measuring serial electrocardiograms while receiving a dose of 50 mcg daily of arformoterol tartrate inhalation solution resulted in an approximately 3.0 ms increase in QT C-F compared to the active comparator, salmeterol. Doses of the related beta 2 -agonist albuterol, when administered intravenously, have been reported to aggravate preexisting diabetes mellitus and ketoacidosis.

5.7 Hypokalemia and Hyperglycemia Beta-agonist medications may produce significant hypokalemia in some patients, possibly through intracellular shunting, which has the potential to produce adverse cardiovascular effects <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.2) ]</span>. The decrease in serum potassium is usually transient, not requiring supplementation. Beta-agonist medications may produce transient hyperglycemia in some patients. Clinically significant and dose-related changes in serum potassium and blood glucose were infrequent during clinical trials with long-term administration of arformoterol tartrate inhalation solution at the recommended dose.

5.8 Immediate Hypersensitivity Reactions Immediate hypersensitivity reactions may occur after administration of arformoterol tartrate inhalation solution as demonstrated by cases of anaphylactic reaction, urticaria, angioedema, rash and bronchospasm.