4. Drug-Drug Interactions
Patient profiles will be assessed to identify those drug regimens which may result in clinically significant drug-drug interactions. Drug interactions considered clinically relevant for short-acting beta2-adrenergic bronchodilators are summarized in Table 6. Only those drug-drug interactions classified as clinical significance level 1 or those considered life-threatening which have not yet been classified will be reviewed.
| Target Drug | Interacting Drug | Interaction | Recommendation | Clinical Significance Level + |
|---|---|---|---|---|
| beta2-agonists | MAOIs (including linezolid) | concurrent administration of MAOIs with beta2-agonists may increase risk of tachycardia, hypomania, or agitation due to potentiation of effects on vascular system | administer combination cautiously or within 2 weeks of MAOI discontinuation; observe patients for adverse effects | 2-major (CP) |
| beta2-agonists | TCAs | concurrent administration of TCAs with beta2-agonists may potentiate effects on cardiovascular system and increase risk of adverse events | cautiously administer TCAs and beta2-agonists together, including within 2 weeks of TCA discontinuation; monitor patients and observe for changes in blood pressure, heart rate and ECG | 3-moderate (CP) |
| beta2-agonists | beta blockers | concurrent administration may decrease effectiveness of beta-adrenergic blocker or beta-2 agonists | combination not recommended in asthma/ COPD patients; if adjunctive therapy necessary, utilize cardioselective beta blocker (e.g., atenolol, bisoprolol) | 2-major (CP) |
| beta2-agonists | diuretics | potential for worsening of diuretic- associated hypokalemia and/or ECG changes with beta2-agonist concurrent administration, especially with high beta2-agonist doses | administer combination cautiously; monitor potassium levels as necessary | 3-moderate (CP) |
| beta2-agonists | atomoxetine | concurrent administration may increase risk of cardiovascular adverse effects (e.g., tachycardia, hypertension); interaction may be less likely with inhaled beta2-agonists | monitor patients for increased cardiovascular adverse effects | 3-moderate (CP) |
| beta2-agonists | QTc interval-prolonging medications (e.g., class I, III anti-arrhythmic, tricyclic antidepressants, dolasetron) | concurrent administration may increase risk of cardiotoxicity (e.g., life-threatening arrhythmias, cardiac arrest) as arformoterol and formoterol may cause QTc interval prolongation and, rarely, torsades de pointes | administer combination cautiously | 2-major, 3-moderate (CP) |
| ipratropium/albuterol | antimuscarinics | co-administration may produce additive anticholinergic effects and potential for increased adverse effects | cautiously administer ipratropium with other antimuscarinics; monitor for increased adverse effects | 3-moderate (CP) |
Legend:
- +CP = Clinical Pharmacology
- COPD = chronic obstructive pulmonary disease
- ECG = electrocardiogram
- MAOIs = monoamine oxidase inhibitors
- TCAs = tricyclic antidepressants