Arformoterol

Arformoterol, 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.

Arformoterol inhalation solution should be used cautiously in patients with hepatic impairment due to increased systemic exposure in these patients.

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.

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, with non-potassium sparing diuretics.

Beta-adrenergic receptor antagonists (beta-blockers) and arformoterol 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.

Concomitant treatment with methylxanthine (aminophylline, theophylline), steroids, or diuretics may potentiate any hypokalemic effect of adrenergic agonists including arformoterol.

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 2-3 bpm and 6-8 mm Hg higher, respectively, in subjects on concomitant theophylline compared with the overall population.

Arformoterol, 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 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 2-4 mm/Hg; for pulse rate the mean of maximal increases were 8.8-12.0 beats/min. Over the course of a one-year study measuring serial electrocardiograms while receiving a dose of 50 mcg daily of arformoterol resulted in an approximately 3.0 ms increase in QT _C-F compared to the active comparator, salmeterol. Doses of the related beta2-agonist albuterol, when administered intravenously, have been reported to aggravate preexisting diabetes mellitus and ketoacidosis.

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 2-4% and 15-20%, 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 than the adult exposure at the MRHDID (on an AUC basis with maternal oral doses of 20,000 mcg/kg/day and higher). Malformations including brachydactyly, bulbous aorta, and liver cysts as well as decreased body weights were observed in rabbit fetuses at doses approximately 26,000 times and higher than the MRHDID in adults (on a mcg/m² basis with maternal oral doses of 40,000 mcg/kg/day and higher). Malformations including adactyly, lobular dysgenesis of the lung, and interventricular septal defect as well as embryolethality were observed in rabbit fetuses at a dose approximately 52,000 times the MRHDID in adults (on a mcg/m² basis with a maternal oral dose of 80,000 mcg/kg/day).

Maternal toxicity was observed at doses approximately 26,000 times and higher than the MRHDID in adults (on a mcg/m² basis with maternal oral doses of 40,000 mcg/kg/day and higher). There was no evidence of fetal harm in rabbits at exposures approximately 4,900 times and lower than the adult exposure at the MRHDID (on an AUC basis with maternal oral doses of 10,000 mcg/kg/day and lower).

In a pre- and post-natal development study, female rats received arformoterol at oral doses of 0, 1,000, 5,000, and 10,000 mcg/kg/day from gestation day 6 through lactation day 20. Lengths of gestation for female rats receiving doses 325 times and higher than the MRHDID (on a mcg/m² basis with maternal oral doses of 1,000 mcg/kg/day and higher) were slightly prolonged, which was attributed to prolonged parturition or dystocia due to the pharmacological action of β-adrenergic agonists such as arformoterol to relax uterine musculature. One female that had received a dose 3,200 times the MRHDID (on a mcg/m² basis with a maternal oral dose of 10,000 mcg/kg/day) was euthanized due to complications during parturition. Pup survival and body weights were decreased at doses 1,600 times and higher than the MRHDID (on a mcg/m² basis with maternal oral doses of 5,000 mcg/kg/day and higher) at birth and during lactation.

Umbilical hernia, a malformation, was observed for 1 pup at a dose 3,200 times the MRHDID (on a mcg/m² basis with a maternal oral dose of 10,000 mcg/kg/day). Potential developmental delays of rat pups were observed at a dose 3,200 times the MRHDID (on a mcg/m² basis with a maternal oral dose of 10,000 mcg/kg/day); however, no developmental delays were evident with doses 1,600 times the MRHDID (on a mcg/m² basis with a maternal oral dose of 5,000 mcg/kg/day).

Risk Summary

There are no data on the presence of arformoterol or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production. However, arformoterol was excreted in the milk of lactating rats. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for arformoterol tartrate and any potential adverse effects on the breastfed infant from arformoterol tartrate or from the underlying maternal condition.

Data

Arformoterol and its metabolites were detected in the milk of lactating rats following oral administration of a 10,000 mcg/kg dose of radiolabeled arformoterol tartrate.

Long-term studies were conducted in mice using oral administration and rats using inhalation administration to evaluate the carcinogenic potential of arformoterol.

In a 24-month carcinogenicity study in CD-1 mice, arformoterol caused a dose-related increase in the incidence of uterine and cervical endometrial stromal polyps and stromal cell sarcoma in female mice at oral doses of 1,000 mcg/kg and above (AUC exposure approximately 70 times adult exposure at the MRHDID).

In a 24-month carcinogenicity study in Sprague-Dawley rats, arformoterol caused a statistically significant increase in the incidence of thyroid gland c-cell adenoma and carcinoma in female rats at an inhalation dose of 200 mcg/kg (AUC exposure approximately 130 times adult exposure at the MRHDID). There were no tumor findings with an inhalation dose of 40 mcg/kg (AUC exposure approximately 55 times adult exposure at the MRHDID).

Arformoterol was not mutagenic or clastogenic in the following tests: mutagenicity tests in bacteria, chromosome aberration analyses in mammalian cells, and micronucleus test in mice.

Arformoterol had no effects on fertility and reproductive performance in rats at oral doses up to 10,000 mcg/kg (approximately 3,200 times the MRHDID in adults on a mcg/m² basis).

Long-acting beta₂-adrenergic agonists, such as Arformoterol Tartrate, as monotherapy (without inhaled corticosteroids) for asthma increase the risk of asthma-related events. Arformoterol tartrate inhalation solution is not indicated for the treatment of asthma.

6.1 Beta₂-Agonist Adverse Reaction Profile

Adverse reactions to arformoterol tartrate inhalation solution are expected to be similar in nature to other beta₂-adrenergic receptor agonists including: angina, hypertension or hypotension, tachycardia, arrhythmias, nervousness, headache, tremor, dry mouth, palpitation, muscle cramps, nausea, dizziness, fatigue, malaise, hypokalemia, hyperglycemia, metabolic acidosis and insomnia.

6.2. Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Adults with COPD in Short-Term Trials (12 weeks)

The safety data described below for adults ≥35 years of age are based on 2 clinical trials of 12 weeks. In the 2 trials of 12 weeks duration, 1456 patients (860 males and 596 females, ages 34 to 89 years old) with COPD were treated with arformoterol tartrate inhalation solution 15 mcg twice daily, 25 mcg twice daily, 50 mcg once daily, salmeterol 42 mcg twice daily, or placebo. The racial/ethnic distribution in these two trials included 1383 Caucasians, 49 Blacks, 10 Asians, and 10 Hispanics, and 4 patients classified as Other.

Among the 1,456 COPD patients in two 12-week, placebo-controlled trials, 288 were treated with arformoterol tartrate inhalation solution 15 mcg twice daily and 293 were treated with placebo. Doses of 25 mcg twice daily and 50 mcg once daily were also evaluated.

Table 1 shows adverse reaction rates among patients from these two trials where the frequency was greater than or equal to 2% in the arformoterol tartrate inhalation solution 15 mcg twice daily group and where the rate in the arformoterol tartrate inhalation solution 15 mcg twice daily group exceeded the rate in the placebo group. The total number and percent of patients who reported adverse events were 202 (70%) in the 15 mcg twice daily and 219 (75%) in the placebo groups. Ten adverse events demonstrated a dose relationship: asthenia, fever, bronchitis, COPD, headache, vomiting, hyperkalemia, leukocytosis, nervousness, and tremor.

Table 1. Number of Patients Experiencing Adverse Events from Two 12-Week, Double-Blind, Placebo-Controlled Clinical Trials:

^* reported termscoded to “lung Disorder” were predominantly pulmonary or chest congestion.

Adverse events occurring in patients treated with arformoterol tartrate inhalation solution 15 mcg twice daily with a frequency of <2%, but greater than placebo, were as follows:

Body as a Whole: abscess, allergic reaction, digitalis intoxication, fever, hernia, injection site pain, neck rigidity, neoplasm, pelvic pain, retroperitoneal hemorrhage

Cardiovascular: arteriosclerosis, atrial flutter, AV block, congestive heart failure, heart block, myocardial infarct, QT interval prolonged, supraventricular tachycardia, inverted T-wave

Digestive: constipation, gastritis, melena, oral moniliasis, periodontal abscess, rectal hemorrhage

Metabolic and Nutritional Disorders: dehydration, edema, glucose tolerance decreased, gout, hyperglycemia, hyperlipemia, hypoglycemia, hypokalemia

Musculoskeletal: arthralgia, arthritis, bone disorder, rheumatoid arthritis, tendinous contracture

Nervous: agitation, cerebral infarct, circumoral paresthesia, hypokinesia, paralysis, somnolence, tremor

Respiratory: carcinoma of the lung, respiratory disorder, voice alteration

Skin and Appendages: dry skin, herpes simplex, herpes zoster, skin discoloration, skin hypertrophy

Special Senses: abnormal vision, glaucoma

Urogenital: breast neoplasm, calcium crystalluria, cystitis, glycosuria, hematuria, kidney calculus, nocturia, PSA increase, pyuria, urinary tract disorder, urine abnormality.

In these trials, the overall frequency of all cardiovascular adverse events was 6.9% in arformoterol tartrate inhalation solution 15 mcg twice daily and 13.3% in the placebo group. There were no frequently occurring specific cardiovascular adverse events for arformoterol tartrate inhalation solution (frequency ≥1% and greater than placebo). The rate of COPD exacerbations was also comparable between the arformoterol tartrate inhalation solution 15 mcg twice daily and placebo groups, 12.2% and 15.1%, respectively.

Adults with COPD in Long-Term (52-week) Safety Trial

arformoterol tartrate inhalation solution was evaluated in one 52 week double-blind, randomized, placebo-controlled, safety trial conducted in patients with moderate to severe COPD. The primary endpoint was time to either respiratory death or first COPD exacerbation-related hospitalization, whichever occurred first. The event had to be a death or hospitalization for which the patient’s respiratory status was predominant and/or inciting contributor, as determined by the clinical investigator. The objective of the trial was to demonstrate that the risk of respiratory death or COPD exacerbation-related hospitalization for patients treated with arformoterol tartrate inhalation solution was not greater than 40% more than the risk for patient treated with placebo. A total of 841 patients (479 males and 361 females, ages 41 to 94 years old) with COPD were randomized: 420 to arformoterol tartrate inhalation solution 15 mcg twice daily and 421 to placebo. Of the randomized patients, 255 (61%) in the arformoterol tartrate inhalation solution group and 211 (50%) in the placebo group, completed one year of treatment. The trial objective was met demonstrating that COPD patients treated with arformoterol tartrate inhalation solution are not at an increased risk of respiratory death or COPD exacerbation-related hospitalizations compared to placebo.