Maalox Plus should not be taken simultaneously with other medicines as they may interfere with their absorption if taken within 1 hour.
Aluminium-containing antacids may prevent the proper absorption of drugs notably H2 antagonists, atenolol, bisphosphonates, cefdinir, cefpodoxime, chloroquine, chlorpromazine, ciprofloxacin, cyclines, dasatinib monohydrate, dexamethasone, diflunisal, digoxin, eltrombopag olamine, elvitegravir, ethambutol, fluoroquinolones, glucocorticoids, hydroxychloroquine, indomethacin, iron salts, isoniazid, ketoconazole, levothyroxine, lincosamides, metoprolol, nilotinib, phenothiazine neuroleptics, penicillamine, propranolol, raltegravir potassium, rifampicin, rilpivirine, riociguat, rosuvastatin, sodium fluorure, antiviral treatment combination of tenofovir alafenamide fumarate/emtricitabine/bictegravir sodium, tetracyclines, and vitamins.
With the integrase inhibitors (dolutegravir, raltegravir, bictegravir) the combination should be avoided (please refer to their SmPC for dose recommendations).
As a precaution, staggering the administration times of any orally administered drug and the antacid by at least 2 hours (4 hours for the fluoroquinolones).
Levothyroxine may also bind to simeticone which may delay or reduce the absorption of levothyroxine.
Polystyrene sulphonate
Caution is advised when used concomitantly with polystyrene sulphonate due to the potential risks of reduced effectiveness of the resin in binding potassium, of metabolic alkalosis in patients with renal failure (reported with aluminium hydroxide and magnesium hydroxide), and of intestinal obstruction (reported with aluminium hydroxide).
Quinidine:
Concomitant use of aluminium products with quinidines may increase the serum levels of quinidine and lead to quinidine overdosage.
Tetracycline:
Because of the aluminium content, Maalox Plus should not be concomitantly administered with tetracycline-containing antibiotics or any tetracycline salts.
Citrates:
Aluminium hydroxide and citrates may result in increased aluminium levels, especially in patients with renal impairment.
Urine alkalinisation secondary to administration of magnesium hydroxide may modify excretion of some drugs; thus, increased excretion of salicylates has been seen.