HeartburnActive ingredient
Famotidine
Histamine-2 receptor antagonist2 FDA labels read
Famotidine is the one medicine in this category that is not a proton pump inhibitor. It is sold over the counter as Pepcid AC and on prescription as tablets, and its label allows something no proton pump inhibitor label here does: taking it in advance, to prevent heartburn rather than to treat it.
Highlights of the labels
- Pepcid AC
- Relieving and preventing heartburncovers heartburn
- Famotidine tablets
- Ulcers, GERD, erosive esophagitiscovers heartburn
- Supply
- Some brands prescription, some over the counter
- Generic
- 54 approved applications
- Boxed warning
- None in these labels
Brands and what each one is approved for
One active ingredient can hold several separate FDA approvals. They are different documents with different approved uses, and mixing them up is the most common mistake made about these medications.
| Brand | What its label approves | Supply | Label version |
|---|---|---|---|
| Pepcid ACKenvue Brands LLC | What its label approvesRelieving and preventing heartburnCovers heartburn | SupplyOver the counter | Label version6 February 2026 |
| Famotidine tabletsSafecor Health, LLC | What its label approvesUlcers, GERD, erosive esophagitisCovers heartburn | SupplyPrescription | Label version11 June 2026 |
How it works
The over-the-counter label gives a window rather than a course: one tablet 15 to 60 minutes before eating or drinking something that causes heartburn. That instruction only makes sense for a medicine expected to act within the hour, and it is the practical difference between this class and the proton pump inhibitors, whose own labels ask for one to four days.
Mechanism of action, Famotidine tablets label
Famotidine is a competitive inhibitor of histamine-2 (H 2) receptors. The primary clinically important pharmacologic activity of famotidine is inhibition of gastric secretion. Both the acid concentration and volume of gastric secretion are suppressed by famotidine, while changes in pepsin secretion are proportional to volume output.
What this product is for
The approved uses, as worded in the label.
Pepcid AC
- Acid reducer
- relieves heartburn associated with acid indigestion and sour stomach
- prevents heartburn associated with acid indigestion and sour stomach brought on by eating or drinking certain food and beverages
Famotidine tablets
- Famotidine tablets are indicated in adults for the: treatment of pathological hypersecretory conditions (e.g., Zollinger-Ellison syndrome, multiple endocrine neoplasias). reduction of the risk of duodenal ulcer recurrence.
- Famotidine is a histamine-2 (H 2) receptor antagonist indicated: In adult and pediatric patients 40 kg and greater for the treatment of: active duodenal ulcer (DU). active gastric ulcer. symptomatic nonerosive gastroesophageal reflux disease (GERD). erosive esophagitis due to GERD, diagnosed by biopsy.
Active ingredient (in each tablet)
The presentations and strengths listed in the label.
Pepcid AC
Famotidine 10 mg
Famotidine tablets
- Famotidine Tablets USP, 20 mg are white to off-white, round, biconvex film-coated tablets debossed with "Z21" on one side and plain on other side.
- Tablets: 20 mg, 40 mg
Directions
What the label states about administration. It is not a dosing instruction for any individual.
Pepcid AC
- adults and children 12 years and over: to relieve symptoms, swallow 1 tablet with a glass of water. Do not chew.
- to prevent symptoms, swallow 1 tablet with a glass of water at any time from 15 to 60 minutes before eating food or drinking beverages that cause heartburn
- do not use more than 2 tablets in 24 hours
- children under 12 years: ask a doctor
Famotidine tablets
- See full prescribing information for complete dosing information, including dosing in renal impairment and recommended treatment duration.
- Administration: Take once daily before bedtime or twice daily in the morning and before bedtime with or without food.
Stop use and ask a doctor if
The adverse reactions the label reports as most common.
Pepcid AC
- your heartburn continues or worsens
- you need to take this product for more than 14 days
Famotidine tablets
most common adverse reactions are: headache, dizziness, constipation and diarrhea.
Warnings
The warnings and precautions section of the label.
Pepcid AC
- had heartburn over 3 months. This may be a sign of a more serious condition.
- heartburn with lightheadedness, sweating, or dizziness
- chest pain or shoulder pain with shortness of breath; sweating; pain spreading to arms, neck or shoulders; or lightheadedness
- frequent chest pain
- frequent wheezing, particularly with heartburn
- unexplained weight loss
- nausea or vomiting
- stomach pain
- kidney disease
Famotidine tablets
- Central Nervous System (CNS)
- Adverse Reactions: Elderly patients and patients with renal impairment at increased risk; reduce the dosage.
- GI Malignancy: Absence of GI symptoms does not preclude the presence of gastric malignancy; evaluate prior to initiating therapy.
Do not use
Situations in which the label states the medication must not be used.
Pepcid AC
- if you have trouble or pain swallowing food, vomiting with blood, or bloody or black stools. These may be signs of a serious condition. See your doctor.
- with other acid reducers
Famotidine tablets
Famotidine is contraindicated in patients with a history of serious hypersensitivity reactions (e.g., anaphylaxis) to famotidine or other histamine-2 (H 2) receptor antagonists.
Drug interactions
Interactions the label singles out.
Famotidine tablets
- Drugs Dependent on Gastric pH for Absorption: Systemic exposure of the concomitant drug may be significantly reduced leading to loss of efficacy. See full prescribing information for a list of interacting drugs.
- Tizanidine (CYP1A2)
- Substrate: Potential for substantial increases in blood concentrations of tizanidine resulting in hypotension, bradycardia or excessive drowsiness; avoid concomitant use, if possible.
Pregnancy and breastfeeding
The opening of the pregnancy section of the label. The full section is longer and is in the source document.
Pepcid AC
If pregnant or breast-feeding, ask a health professional before use.
Famotidine tablets
Available data with H 2 -receptor antagonists, including famotidine, in pregnant women are insufficient to establish a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. In animal reproduction studies, no adverse development effects were observed with oral administration of famotidine at doses up to approximately 243 times and 122 times, respectively, the recommended human dose of 80 mg per day for the treatment of erosive...
Generic or brand
Generic famotidine is approved in both prescription and shop form.
The FDA label database lists 54 approved generic applications for this ingredient.
What affects the cost
Famotidine is an old generic sold cheaply over the counter. The prescription strengths are separate products with their own pricing, and no label discusses cost.
What pharmacies pay for it
These are acquisition costs: what pharmacies in the United States pay on average to buy the medication, published weekly by the Centers for Medicare and Medicaid Services. They are not retail prices and not what a person pays at the counter, which depends on insurance, pharmacy and discount programs. They are useful as an objective floor and for seeing how far a brand sits above its generic.
| Measured | Generic |
|---|---|
| per tablet, capsule or pen | Generic$0.051 (range $0.029 to $0.147, 3107 listings) |
| per milliliter | Generic$0.154 (range $0.078 to $0.494, 636 listings) |
Median of 3743 listings. Effective dates 2025-03-19 to 2026-08-19, file dated 2026-08-26.
What the FDA has changed in these labels
The regulator reissues a label without notice: the old wording simply stops existing. These are the latest revisions on record for the documents this page is built from.
- 14 December 2016Pepcid ACfrom the archive
Warnings (1 added, 1 removed); Do not use (reworded)
Compared with other medications
What the labels do not do is compare one medication against another. These pages put two of them side by side.
Common questions
- Can famotidine be taken before a meal to prevent heartburn?
- The Pepcid AC label says so directly: to prevent symptoms, swallow one tablet at any time from 15 to 60 minutes before eating food or drinking beverages that cause heartburn. It also sets a limit of two tablets in 24 hours.
- How does it differ from omeprazole?
- Different class and different label logic. Famotidine is a histamine-2 receptor antagonist, and its shop label describes both relieving and preventing heartburn. Omeprazole is a proton pump inhibitor whose label describes a 14-day course and states that it is not intended for immediate relief.
- What does the prescription label add?
- Higher strengths, 20 mg and 40 mg, and approved uses the shop label does not carry: active duodenal and gastric ulcers, GERD, erosive esophagitis and pathological hypersecretory conditions. It also covers pediatric patients weighing 40 kg and more.
Other medications under heartburn
Whether each one carries an FDA approval for this use is marked on its page and in this list.
Sources
Every fact above comes from one of these documents. The date is the effective date of the label version this page was built from.
FDA prescribing information for Pepcid AC
Kenvue Brands LLC. Label version 20, effective 6 February 2026.
FDA prescribing information for Famotidine tablets
Safecor Health, LLC. Label version 3, effective 11 June 2026.
Each stripe is one section of the label, each division in a stripe one entry in that section.
Page last updated 29 August 2026
Compiled by the HealthyStudy editorial team from FDA source documents. No medical reviewer is credited on this page, because none reviewed it.