Drug Interaction Report

MONITOR: Topically administered alpha-2 adrenergic receptor agonists such as apraclonidine and brimonidine are systemically absorbed, with the potential for producing rare but clinically significant systemic effects such as hypotension and bradycardia. The possibility for an additive or potentiating effect on blood pressure and heart rate should be considered when used with other medications that affect these parameters, such as ophthalmic and systemic beta blockers, vasodilators, cardiac glycosides, and antihypertensive agents.

MANAGEMENT: Blood pressure and pulse rate should be monitored regularly when topical alpha-2 adrenergic receptor agonists are prescribed in combination with cardiovascular drugs. Patients should be advised to notify their physician if they experience slow pulse, irregular heartbeat, dizziness, lightheadedness, or syncope.

MONITOR: Glucagon-like peptide-1 (GLP-1) receptor agonists and dual GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) receptor agonists can delay gastric emptying, which may impact the absorption of concomitantly administered oral medications. Mild to moderate decreases in plasma concentrations of coadministered drugs have been demonstrated in pharmacokinetic studies for some GLP-1 receptor agonists (e.g., exenatide, lixisenatide), but not others. According to the prescribing information, liraglutide did not affect the absorption of several orally administered drugs to any clinically significant extent, including acetaminophen, atorvastatin, digoxin, griseofulvin, lisinopril, and an oral contraceptive containing ethinyl estradiol-levonorgestrel. Likewise, no clinically relevant effect on absorption was observed for concomitantly administered oral drugs studied with albiglutide (digoxin, ethinyl estradiol-norethindrone, simvastatin, warfarin), dulaglutide (acetaminophen, atorvastatin, digoxin, ethinyl estradiol-norelgestromin, lisinopril, metformin, metoprolol, sitagliptin, warfarin), or semaglutide (atorvastatin, digoxin, ethinyl estradiol-levonorgestrel, metformin, warfarin). The impact of dual GLP-1 and GIP receptor agonist tirzepatide on gastric emptying was reported to be dose- and time-dependent, with the greatest effect observed after a single 5 mg dose but diminished after subsequent doses. When acetaminophen was administered following a single 5 mg dose of tirzepatide, acetaminophen peak plasma concentration (Cmax) was decreased by 50% and its median time to peak plasma concentration (Tmax) delayed by 1 hour. However, no significant impact on acetaminophen Cmax and Tmax was observed after 4 consecutive weekly doses of tirzepatide (5 mg/5 mg/8 mg/10 mg), and the overall exposure (AUC) of acetaminophen was unaffected. Tirzepatide at lower doses of 0.5 mg and 1.5 mg also had minimal effects on acetaminophen exposure.

MANAGEMENT: Although no specific dosage adjustment of concomitant medications is generally recommended based on available data, potential clinical impact on some oral medications cannot be ruled out, particularly those with a narrow therapeutic index or low bioavailability, those that depend on threshold concentrations for efficacy (e.g., antibiotics), and those that require rapid gastrointestinal absorption (e.g., hypnotics, analgesics). Pharmacologic response to concomitantly administered oral medications should be monitored more closely following initiation, dose adjustment, or discontinuation of a GLP-1 receptor agonist or a dual GLP-1 and GIP receptor agonist.