Types of medicine
What Is an Antacid? Uses and Interaction Warnings
Antacid · say it: ant-AS-idAlso written: antacids, acid neutralizer, indigestion remedy
Short answer
An antacid is a medicine that neutralises stomach acid to give quick relief from heartburn and indigestion.
What it means
Antacids are medicines that neutralise acid already in the stomach. They usually contain minerals such as calcium carbonate, magnesium hydroxide or aluminium hydroxide. They act within minutes, but their effect is short. Some also contain alginate, which forms a layer that helps keep acid from rising into the food pipe.
Antacids show up on labels in two ways. Their own labels give uses, directions and limits, such as a maximum number of doses a day and advice to see a doctor if symptoms last more than two weeks. Many other medicine labels mention antacids under interactions, because the minerals in antacids can stick to certain medicines, such as some antibiotics, HIV medicines and thyroid tablets, and stop them being absorbed. Those labels advise spacing the doses.
Antacids are different from H2 blockers and proton pump inhibitors, which reduce how much acid the stomach makes rather than neutralising it.
Where you may see it
- Over-the-counter antacid labels ('Uses', 'Directions', 'Warnings')
- The 'Drug Interactions' section of many prescription labels
- Pharmacy advice leaflets
📄 How it looks on a report
Take this medicine at least 2 hours before or 2 hours after antacids.
🙅 What it does not mean
- Antacids are not completely harmless; taking too much can upset mineral balance, especially with kidney problems.
- They relieve symptoms but do not heal an ulcer or treat the cause of frequent heartburn.
- The spacing advice on other labels does not mean you can never take antacids, just not at the same time.
🗒️ Questions to ask your doctor
💊 Medicines whose labels mention “Antacid”
Plain-English explanations of each medicine, from its official FDA label.
- Alendronate
a bisphosphonate, a medicine that slows the breakdown of bone by blocking cells called osteoclasts
- Apixaban
A factor Xa inhibitor, a blood thinner medicine (anticoagulant)
- Azithromycin
a macrolide antibacterial (antibiotic) medicine
- Ciprofloxacin
a fluoroquinolone antibacterial medicine
- Dolutegravir
an HIV-1 integrase strand transfer inhibitor (INSTI), a type of HIV medicine
- Doxycycline
a tetracycline-class antibacterial medicine (an antibiotic)
- Famotidine
A histamine-2 (H2) receptor blocker, a type of medicine that lowers stomach acid.
- Fexofenadine
an antihistamine, an allergy medicine sold over the counter
- Gabapentin
An antiepileptic (seizure) medicine. The label also describes it as a treatment for nerve pain after shingles.
- Levofloxacin
an antibiotic of the fluoroquinolone type
🔗 Read more from trusted sources
- “Antacid” on MedlinePlus ↗
US National Library of Medicine
Seeing this word on your own report? Get every line of it explained, free.
Explain my report🧩 Related words
🔎 Look up another word
More words: types of medicine
General information about a medical word, not advice about your own results. Ask the clinician who ordered the test what it means for you.