Editing Antacid (section)

== Interactions ==
[[File:Basic structure of tetracycline chelating a metal.svg|thumb|Structural depiction of tetracycline metal chelation, where 'M' is a metal such as those found in antacids]]
Antacids are known to [[Drug interaction|interact]] with several [[Oral administration|oral medications]], including [[Quinolone antibiotic|fluoroquinolone]] and [[tetracycline]] [[antibiotic]]s, [[iron]], [[itraconazole]], and [[prednisone]].<ref name="Ogawa_2011">{{cite journal | vauthors = Ogawa R, Echizen H | title = Clinically significant drug interactions with antacids: an update | journal = Drugs | volume = 71 | issue = 14 | pages = 1839–1864 | date = October 2011 | pmid = 21942976 | doi = 10.2165/11593990-000000000-00000 | s2cid = 36875514 }}</ref> Metal [[chelation]] is responsible for some of these interactions (e.g. [[fluoroquinolones]], [[tetracyclines]]), leading to decreased absorption of the chelated drug. Some interactions may be due to the [[pH]] increase observed in the [[stomach]] following antacid [[ingestion]], leading to increased absorption of weak acids, and decreased absorption of weak bases.{{Citation needed|date=January 2024}} Antacids also cause an increase in [[pH]] of the [[urine]] (alkalization), which may cause increased [[blood]] concentrations of weak bases, and increased [[excretion]] of weak acids.<ref name="Patel_2020">{{cite journal | vauthors = Patel D, Bertz R, Ren S, Boulton DW, Någård M | title = A Systematic Review of Gastric Acid-Reducing Agent-Mediated Drug-Drug Interactions with Orally Administered Medications | journal = Clinical Pharmacokinetics | volume = 59 | issue = 4 | pages = 447–462 | date = April 2020 | pmid = 31788764 | pmc = 7109143 | doi = 10.1007/s40262-019-00844-3 }}</ref>

A proposed method to mitigate the effects of [[stomach]] acidity and [[chelation]] on drug absorption is to space out the administration of antacids with interacting [[medication]]s by at least two hours,<ref>{{Cite book |last=Australian Medicines Handbook Pty Ltd |title=Australian Medicines Handbook 2022 |year=2022 |isbn=978-0-6485158-6-9 |location=Adelaide, SA}}</ref> however this method has not been well studied for drugs affected by [[Urine|urine alkalization]].<ref name="Ogawa_2011" />

There are concerns regarding interactions between delayed-release tablets and antacids, as antacids may increase the stomach [[pH]] to a point at which the coating of the delayed-release tablet will dissolve, leading to degradation of the drug if it is [[PH|pH sensitive]].<ref name="Patel_2020" />