Drug Interactions between aluminum hydroxide / diphenhydramine / lidocaine / magnesium hydroxide / simethicone topical and tirzepatide

GENERALLY AVOID: The concomitant administration of aluminum-containing products (e.g., antacids and phosphate binders) and citrates may significantly increase serum aluminum concentrations, resulting in toxicity. Citrates or citric acid are contained in numerous soft drinks, citrus fruits, juices, and effervescent and dispersible drug formulations. Citrates enhance the gastrointestinal absorption of aluminum by an unknown mechanism, which may involve the formation of a soluble aluminum-citrate complex. Various studies have reported that citrate increases aluminum absorption by 4.6- to 50-fold in healthy subjects. Patients with renal insufficiency are particularly at risk of developing hyperaluminemia and encephalopathy. Fatalities have been reported. Patients with renal failure or on hemodialysis may also be at risk from soft drinks and effervescent and dispersible drug formulations that contain citrates or citric acid. It is unknown what effect citrus fruits or juices would have on aluminum absorption in healthy patients.

MANAGEMENT: The concomitant use of aluminum- and citrate-containing products and foods should be avoided by renally impaired patients. Hemodialysis patients should especially be cautioned about effervescent and dispersible over-the-counter remedies and soft drinks. Some experts also recommend that healthy patients should separate doses of aluminum-containing antacids and citrates by 2 to 3 hours.

ADJUST DOSING INTERVAL: The administration of aluminum-containing antacids with enteral nutrition may result in precipitation, formation of bezoars, and obstruction of feeding tubes. The proposed mechanism is the formation of an insoluble complex between the aluminum and the protein in the enteral feeding. Several cases of esophageal plugs and nasogastric tube obstructions have been reported in patients receiving high-protein liquids and an aluminum hydroxide-magnesium hydroxide antacid or an aluminum hydroxide antacid.

MANAGEMENT: Some experts recommend that antacids should not be mixed with or given after high protein formulations, that the antacid dose should be separated from the feeding by as much as possible, and that the tube should be thoroughly flushed before administration.

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.

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.