ARFORMOTEROL TARTRATE
Clinical safety rating: safe
Animal studies have demonstrated safety
Long-acting beta2-adrenergic receptor agonist (LABA) that stimulates intracellular adenyl cyclase, increasing cyclic AMP levels, leading to bronchodilation.
| Metabolism | Primarily via glucuronidation (UGT1A1, UGT2B7) and to a lesser extent via CYP2D6 and CYP2C19. |
| Excretion | Primarily renal (63%) and fecal (26%) as conjugated metabolites; <12% unchanged in urine. |
| Half-life | Terminal elimination half-life approximately 7-8 hours, supporting twice-daily dosing in asthma/COPD. |
| Protein binding | 52-65% bound to human plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 4.6 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Inhalation: approximately 15-18% systemic bioavailability; negligible oral bioavailability due to first-pass metabolism. |
| Onset of Action | Inhalation: within 5 minutes; peak bronchodilation at 1-3 hours. |
| Duration of Action | 12 hours or more; provides sustained bronchodilation for twice-daily dosing in asthma and COPD. |
Inhalation: 15 mcg twice daily (morning and evening) via nebulization. For bronchospasm prevention, maximum 30 mcg twice daily.
| Dosage form | SOLUTION |
| Renal impairment | No specific GFR-based dose adjustment recommended; use with caution in severe renal impairment due to limited data. |
| Liver impairment | Child-Pugh Class A, B, C: No dosage adjustment necessary; however, caution in severe hepatic impairment due to potential increased systemic exposure. |
| Pediatric use | Children 5-12 years: 15 mcg twice daily via nebulization. Children >12 years: same as adult. Not established in children <5 years. |
| Geriatric use | No specific dose adjustment; monitor for adverse effects due to potential age-related renal/hepatic decline and concomitant medications. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Other adrenergic drugs can have additive cardiovascular effects Can cause paradoxical bronchospasm and increase the risk of asthma-related death.
| Breastfeeding | It is unknown if arformoterol is excreted in human milk. In animal studies, arformoterol was detected in milk of lactating rats at concentrations similar to plasma. The M/P ratio is not determined in humans. Caution should be exercised when administered to a nursing woman. Consider developmental and health benefits of breastfeeding with mother's clinical need for arformoterol. |
| Teratogenic Risk | Pregnancy Category C. In animal studies, arformoterol caused fetal harm (increased fetal loss, decreased fetal weight, skeletal abnormalities) at doses ≥ 1.4 times the maximum recommended human daily inhalation dose. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to fetus. First trimester: no human data; animal data suggest risk. Second/third trimester: no human studies; may cause uterine relaxation and delay labor. |
■ FDA Black Box Warning
LABAs increase the risk of asthma-related death; therefore, arformoterol should only be used in patients with asthma not adequately controlled on other asthma controller medications or whose disease severity clearly warrants initiation of LABA therapy.
| Common Effects | COPD |
| Serious Effects |
Hypersensitivity to arformoterol or any component of the formulation; use as monotherapy without an inhaled corticosteroid for asthma treatment (due to black box warning).
| Precautions | Asthma-related death, paradoxical bronchospasm, cardiovascular effects (e.g., increased heart rate, blood pressure), hypokalemia, hyperglycemia, immediate hypersensitivity reactions, and deterioration of disease. |
| Food/Dietary | No specific food interactions. Avoid excessive caffeine intake as it may increase stimulant effects. |
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| Fetal Monitoring | Monitor maternal heart rate, blood pressure, and serum potassium (beta-agonists can cause hypokalemia). Assess fetal heart rate and uterine activity if used for tocolysis (off-label) or during labor. Monitor for signs of pulmonary edema if used in preterm labor. Evaluate respiratory status (peak expiratory flow, FEV1) for efficacy. |
| Fertility Effects | No human data on fertility effects. In animal studies, arformoterol did not impair fertility in rats at doses up to 18 mcg/kg/day (approximately 10 times the MRHDID). No effect on mating or reproductive performance noted. |
| Clinical Pearls | Arformoterol is a long-acting beta2-agonist (LABA) indicated for maintenance treatment of COPD, not acute bronchospasm. It has a rapid onset (7 minutes) but should not be used as rescue therapy. Monitor for paradoxical bronchospasm, cardiovascular effects (tachycardia, hypertension, QT prolongation), and hypokalemia. Use with caution in patients with seizure disorders, thyrotoxicosis, or those taking MAOIs or tricyclic antidepressants. Do not exceed the recommended dose. |
| Patient Advice | Do not use for sudden breathing problems; always have a rescue inhaler available. · Use exactly as prescribed; do not increase dose or frequency. · Rinse mouth with water after each use to prevent oral thrush. · Common side effects include headache, back pain, and diarrhea. · Seek medical help if you experience chest pain, fast heartbeat, or worsening breathing. · Tell your doctor about all medications, especially beta-blockers, diuretics, or antidepressants. |