Pepcid Uses, Dosage, Side Effects, Food Interaction and all others data.

Pepcid is a histamine H2-receptor antagonist. Pepcid completely inhibits the action of histamine on H2-receptors of parietal cell. It inhibits basal, overnight and pentagastrin stimulated gastric acid secretion. The H2-receptor antagonist activity of Pepcid is slowly reversible, since the drug dissociates slowly from H2-receptor.

Pepcid decreases the production of gastric acid, suppresses acid concentration and pepsin content, and decreases the volume of gastric secretion. Pepcid inhibits both basal and nocturnal gastric acid secretion, as well as acid secretion stimulated by food, caffeine, insulin, and pentagastrin.

Pepcid has a dose-dependent therapeutic action, with the highest dose having the most extended duration of action and the highest inhibitory effect on gastric acid secretion. Following oral administration, the onset of action is within one hour, and the peak effect is reached within 1-3 hours. The duration of effect is about 10-12 hours.

Trade Name Pepcid
Availability Rx and/or OTC
Generic Famotidine
Famotidine Other Names Famotidina, Famotidine, Famotidinum
Related Drugs omeprazole, pantoprazole, Nexium, Pepcid, Protonix, esomeprazole, sucralfate, Prilosec, ranitidine, lansoprazole
Type Injection, Powder For Oral Suspension
Formula C8H15N7O2S3
Weight Average: 337.445
Monoisotopic: 337.044934829
Protein binding

The protein binding of famotidine is about 15 to 22%.

Groups Approved
Therapeutic Class H2 receptor antagonist
Available Country Canada, United States,
Last Updated: September 19, 2023 at 7:00 am


Pepcid is used for-

  • Short term treatment of active duodenal ulcer and benign gastric ulcer
  • Maintenance therapy for prevention of relapses of duodenal ulceration
  • Gastro-oesophageal reflux disease
  • Zollinger Ellison Syndrome

Pepcid is also used to associated treatment for these conditions: Chronic Back Pain, Duodenal Ulcer, Erosive Esophagitis, Extra-Articular Rheumatism, Gastritis, Heartburn, Helicobacter Pylori Infection, Multiple Endocrine Neoplasia, Muscle Spasms, Nonspecific Pain Post Traumatic Injury, Osteoarthritis (OA), Postoperative pain, Stress Ulcers, Zollinger-Ellison Syndrome, Active Gastric ulcer, Acute Duodenal Ulcers, Gastrointestinal ulceration, Pathological hypersecretory conditions, Symptomatic non-erosive gastroesphageal reflux disease

How Pepcid works

Histamine acts as a local hormone that stimulates the acid output by parietal cells via a paracrine mechanism. Neuroendocrine cells called enterochromaffin-like (ECL) cells lie close to the parietal cells and regulate the basal secretion of histamine. Histamine release is also promoted from stimulation by acetylcholine and gastrin, a peptide hormone. Gastrin (G) cells release gastrin, which works on CCK2 receptors on ECL cells. This action promotes the release of histamine from ECL cells. Upon release, histamine acts on H2 receptors expressed on the basolateral membrane of parietal cells, leading to increased intracellular cAMP levels and activated proton pumps on parietal cells. Proton pump releases more protons into the stomach, thereby increasing the secretion of acid. In conditions that are associated with acid hypersecretion such as ulcers, there is a loss of regulation of acid secretion. Pepcid works on H2 receptors and blocks the actions of histamine.


Pepcid dosage

Duodenal ulcer: 40 mg at night for 4 to 8 weeks

Benign gastric ulcer: 40 mg at night for 4 to 8 weeks; Maintenance therapy: 20 mg at night for preventing the recurrences of duodenal ulceration

Gastro-oesophageal reflux disease: 20 mg twice daily for 6 to 12 weeks

Zollinger Ellison syndrome: The recommended starting dose is 20 mg every six hours. Dosage should then be adjusted to individual response. Doses up to 160 mg every six hours have been administered to some patients without the development of significant adverse effects.

Dosage can be administered irrespective of meals. Antacids may be given concomitantly if needed.

Side Effects

Pepcid is generally well tolerated and side effects are uncommon. Dizziness, headache, constipation and diarrhoea have been reported rarely. Other side effects reported less frequently include dry mouth, nausea and/or vomiting, rash, abdominal discomfort, anorexia and fatigue.


The oral LD50 is 4049 mg/kg in rats and 4686 mg/kg in mice. The subcutaneous LD50 is 800 mg/kg in rats and mice. The lowest published toxic dose (TDLo) in man following oral administration is 4 mg/kg/7D.

Symptoms of overdose resemble the adverse events seen with the use of recommended doses, and they should be responded with supportive and symptomatic treatment. Any unabsorbed drug should be removed from the gastrointestinal tract, and the patient should be monitored accordingly. The use of hemodialysis to eliminate the drug from the systemic circulation is effective, but the experience of using hemodialysis in response to famotidine overdose is limited in clinical settings.


Dosage reduction should be considered or interval between doses should be prolonged if creatinine clearance falls to or below 30 ml/min.


Pepcid does not interact with the cytochrome P450 linked drug metabolising enzyme system. So, no interactions have been found in man with Warfarin, Theophylline, Phenytoin, Diazepam, Propranolol, Aminopyrine or antipyrine.

Food Interaction

  • Avoid excessive or chronic alcohol consumption. Alcohol increases the risk of gastric irritation.
  • Limit caffeine intake. Caffeine and other acidic beverages increases the risk of gastric irritation.
  • Take with or without food. Food slightly increases bioavailability, but not to a clinically significant extent.

Volume of Distribution

The steady-state volume of distribution ranges from 1.0 to 1.3 L/kg. Pepcid is found in breast milk; however, it is found in breast milk at the lowest concentrations compared to other H2 receptor antagonists.

Elimination Route

Following oral administration, the absorption of famotidine is dose-dependent and incomplete. The oral bioavailability ranges from 40-50%, and the Cmax is reached in 1-4 hours post-dosing. While the bioavailability can be slightly increased with the intake of food and decreased by antacids, there is no clinical significance.

Half Life

The elimination half-life is about 2 to 4 hours. The half-life is expected to increase nonlinearly in patients with decreased renal function.


Renal clearance is 250-450 mL/min, indicating some tubular excretion. Because the renal clearance rate exceeds the glomerular filtration rate, famotidine is thought to be mainly eliminated via both glomerular filtration and renal tubular secretion.

Elimination Route

About 65-70% of the total administered dose of famotidine undergoes renal elimination, and 30-35% of the dose is cleared by metabolism. Following intravenous administration, about 70% of the drug is eliminated in the urine as an unchanged drug.

Pregnancy & Breastfeeding use

Pregnancy: There are no adequate, well controlled studies on Pepcid in pregnancy, but it is known to cross the placenta and should be prescribed only if clearly needed.

Lactation: It is not known whether Pepcid is secreted into human milk, nursing mothers should either stop nursing or stop taking the drug.


There are no known contraindication to Pepcid. If any evidence of hypersensitivity appear, the therapy should be discontinued and consultation with physician is required.

Storage Condition

Tablet: Store between 15-30° C. Concentrate for injection: Store between 2-8° C.

Innovators Monograph

You find simplified version here Pepcid

Pepcid contains Famotidine see full prescribing information from innovator Pepcid Monograph, Pepcid MSDS, Pepcid FDA label


What is Pepcid used for?

Pepcid  is used to treat stomach ulcers, erosive esophagitis, and gastroesophageal reflux a histamine H₂ receptor antagonist medication that decreases stomach acid production. It is used to treat peptic ulcer disease, gastroesophageal reflux disease, and Zollinger-Ellison syndrome.

How does Pepcid work?

Pepcid works by decreasing the amount of acid produced by the stomach.

What are the common side effects of Pepcid?

Common side effects of Pepcid are include:

  • Anxiety.
  • blistering, peeling, or loosening of the skin.
  • blood in the urine or stools.
  • bloody, black, or tarry stools.
  • difficulty breathing.
  • discouragement.
  • fast, irregular, pounding, or racing heartbeat or pulse.
  • feeling sad or empty.

Is Pepcid safe during pregnancy?

Use is recommended only if clearly needed and the benefit outweighs the risk.Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.

Is Pepcid safe during breastfeeding?

Pepcid doses in breastmilk result in infant dosages that are lower than those used in newborn infants. Pepcid would not be expected to cause any adverse effects in breastfed infants. No special precautions are required.

Can I drink alcohol with Pepcid?

Avoid drinking alcohol. It can increase the risk of damage to your stomach. Avoid taking other stomach acid reducers unless your doctor has told you to.

How should I take Pepcid?

Pepcid can be taken with or without food. To prevent heartburn and acid indigestion, take Pepcid 15-60 minutes before eating food or drinking beverages that can cause indigestion.

How often should I use Pepcid?

Do not take more than 2 tablets in 24 hours unless directed by your doctor. Adults 20 milligrams every 6 hours. Your doctor may adjust your dose as needed. Children use and dose must be determined by your doctor.

Is it better to take Pepcid in the morning or at night?

If you are taking this Pepcid once daily, it is usually taken right before bedtime.

How long does it take Pepcid to take effect?

The effect of Pepcid can be felt within one hour and can last up to 12 hours depending on the dose taken.

What is the half life of Pepcid?

The plasma half-life is about 3 hours both after oral single doses and during repeated administration.

Can I take Pepcid for a long time?

Pepcid in 24 hours and do not take over-the-counter Pepcid for longer than 2 weeks unless your doctor tells you that you should.

Who should not take Pepcid?

Do not self-medicate with Pepcid if you are over the age of 40 and this is the first time you have had heartburn or indigestion; have a family history of gastric cancer; have coughing spells; use NSAIDs anti-inflammatories; have difficulty or pain when swallowing; already take other.

Does Pepcidc affect blood pressure?

Pepcid demonstrated cardiac function improvements, including a slight decrease in both systolic and diastolic blood pressure.

Does Pepcid cause joint pain?

Pepcid can causes joint pain also with other side effects.

Can Pepcid cause blurry vision?

transient and mild blurred vision has been reported,

Can Pepcid cause heart problems?

Pepcid not associated with increased cardiovascular risk.

What happens if I miss a dose of Pepcid?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happen if I take too much Pepcid?

If you take too much you could have dangerous levels of the drug in your body. Symptoms of an overdose of this drug can include: agitation, confusion.

What happen If I stop taking Pepcid?

If you stop taking the drug suddenly or don't take it at all: Your acid reflux, heartburn, or ulcer symptoms may not get better or may get worse.

*** Taking medicines without doctor's advice can cause long-term problems.