Table 5.
Medications with a clinically meaningful other mechanism of interaction, not gastric pH-based (n = 83)
| Victim drug | ARA/perpetrator | Mechanism of interaction |
|---|---|---|
| Anti-infectives | ||
| Azithromycin | Magnesium-/aluminum-containing antacids | Likely chelation |
| Bictegravir | Antacids | Likely chelation |
| Chloroquine | Cimetidine | Inhibition of CYP |
| Ciprofloxacin | Magnesium-/aluminum-containing antacids | Chelation |
| Dolutegravir | Calcium-based antacids | Chelation |
| Doxycycline | Magnesium-/aluminum-/calcium-containing antacids, PPIs | Likely chelation |
| Gemifloxacin | Magnesium-/aluminum-containing antacids | Chelation |
| Levofloxacin | Magnesium-/aluminum-containing antacids | Chelation |
| Methenamine | Antacids | Urine alkalization |
| Minocycline | Magnesium-/aluminum-/calcium-containing antacids | Likely chelation |
| Moxifloxacin | Magnesium-/aluminum-containing antacids | Chelation |
| Norfloxacin | Cation-containing antacidsa | Chelation |
| Quinine sulfate | Antacids/H2RAs | Chelation/inhibition of CYP3A4 |
| Tetracycline | Magnesium-/aluminum-/calcium-containing antacids | Likely chelation |
| CNS agents | ||
| Alprazolam | Cimetidine | Inhibition of CYP3A4 |
| Carbamazepine | Cimetidine | Likely inhibition of CYP3A4 |
| Citalopram | Cimetidine/omeprazole | Likely inhibition of CYP/inhibition of CYP2C19 |
| Clobazam | Omeprazole | Inhibition of CYP2C19 |
| Clozapine | Cimetidine | Inhibition of CYP3A4 |
| Dalfampridine | Cimetidine | Inhibition of OCT2 |
| Desipramine | Cimetidine | Likely inhibition of CYP |
| Doxepin | Cimetidine | Likely inhibition of CYP |
| Escitalopram | Cimetidine/proton pump inhibitors | Likely inhibition of CYP/inhibition of CYP2C19 |
| Gabapentin | Antacid containing aluminum and magnesium | Possible chelation |
| Lisdexamfetamine | Sodium bicarbonate | Urine alkalization |
| Memantine | Antacids (sodium bicarbonate) | Urine alkalization |
| Mirtazapine | Cimetidine | Likely inhibition of CYP |
| Paroxetine | Cimetidine | Likely inhibition of CYP |
| Pramipexole | Cimetidine | Inhibition of OCT2 |
| Sulpiride | Antacids | Unknown |
| Tizanidine | Cimetidine | Inhibition of CYP1A2 |
| Zolmitriptan | Cimetidine | Likely inhibition of CYP |
| Cardiovascular agents | ||
| Captopril | Antacids | Unknown |
| Carvedilol | Cimetidine | Likely inhibition of CYP |
| Diltiazem | Cimetidine | Likely inhibition of CYP3A4 |
| Dofetilide | Cimetidine | Inhibition of renal tubular secretion |
| Felodipine | Cimetidine | Inhibition of CYP3A4 |
| Fosinopril | Antacids | Unknown |
| Nifedipine | Cimetidine | Inhibition of CYP |
| Nimodipine | Cimetidine | Inhibition of CYP3A4 |
| Nisoldipine | Cimetidine | Likely inhibition of CYP3A4 |
| Nitrendipine | Cimetidine | Likely inhibition of CYP |
| Pindolol | Cimetidine | Likely inhibition of CYP or inhibition of renal clearance |
| Procainamide | Cimetidine | Likely inhibition of renal tubular secretion |
| Propafenone | Cimetidine | Likely inhibition of CYP |
| Quinidine | Cimetidine | Likely inhibition of CYP3A4 |
| Rosuvastatin | Antacids | Possible chelation |
| Sotalol | Aluminum- and/or magnesium-containing antacids | Likely chelation |
| Verapamil | Cimetidine | Likely inhibition of CYP3A4 |
| Immune suppressant agents | ||
| Cyclosporine | H2RAs | Unknown |
| Mycophenolate mofetil | Antacids with magnesium and/or aluminum hydroxide | Chelation |
| Mycophenolic acid | Antacids with magnesium and/or aluminum hydroxide | Chelation |
| Tacrolimus | Proton pump inhibitors | Likely inhibition of CYP3A4 |
| Blood-modifying agents | ||
| Acenocoumarol | Cimetidine | Inhibition of CYP |
| Cilostazol | Omeprazole | Inhibition of CYP2C19 |
| Clopidogrel | Proton pump inhibitors (esomeprazole, omeprazole) | Inhibition of CYP2C19 |
| Eltrombopag | Cation-containing antacidsa | Chelation |
| Warfarin | Cimetidine | Inhibition of hydroxylation in the liver |
| Metal chelators | ||
| Deferasirox | Aluminum-containing antacids | Chelation |
| Deferiprone | Antacids | Chelation |
| Trientine | Antacids | Metal binding/chelation |
| Anti-diabetic agents | ||
| Glimepiride | H2RAs (cimetidine, famotidine, nizatidine, ranitidine) | Inhibition of metabolism and/or renal transport |
| Glipizide | H2RAs (cimetidine, famotidine, nizatidine, ranitidine) | Inhibition of metabolism and/or renal transport |
| Metformin | Cimetidine | Likely inhibition of OCT2 |
| Tolbutamide | Cimetidine | Inhibition of metabolism and/or renal transport |
| Bisphosphonate | ||
| Alendronate | Antacids | Likely chelation |
| Antirheumatic | ||
| Penicillamine | Antacids | Likely chelation |
| Chemotherapy | ||
| 5-Fluorouracil | Cimetidine | Likely a combination of inhibition of metabolism and decreased liver blood flow |
| Exchange resin | ||
| Sodium polystyrene sulfonate | Antacids | Likely chelation |
| Gastrointestinal agents | ||
| Alosetron | Cimetidine | Inhibition of CYP1A2 |
| Respiratory agents | ||
| Roflumilast | Cimetidine | Inhibition of CYP3A4 |
| Urinary agents | ||
| Tamsulosin | Cimetidine | Inhibition of CYP3A4 |
| Lanthanum carbonate | Antacids | Unclear, possible chelation |
| Cholinergic agonist | ||
| Varenicline | H2RAs (cimetidine, famotidine, nizatidine, ranitidine) | Possible inhibition of OCT2 |
Medications were identified via searches and screens of the PDR3D: Reed Tech Navigator™, University of Washington Drug–Drug Interaction Database (DIDB), and DailyMed databases as detailed in Sect. 4.1
ARA acid-reducing agent, CNS central nervous system, CYP cytochrome P450, H2RA histamine H2 receptor antagonist, OCT2 organic cation transporter 2
aIt is suspected that ‘cation-containing antacids’ refer to polyvalent cations and not sodium bicarbonate when the mechanism of interaction is chelation