Famotidine Side Effects, How it Works, Upsides & Downsides

Famotidine is an over-the-counter and a prescribed medicinal drug that deals with acid regulation inside the stomach and all the illness that occur because of it. It is used to treat GERD, Zollinger-Ellison syndrome, intestinal ulcers (duodenal), stomach ulcers, and heartburn. Famotidine cuts the excess amount of acid produced in the stomach and relieves its symptoms.


This drug is packaged under the brand name Pepcid, and by nature is an H-2 inhibitor. Pepcid is present in the form of oral tablets, liquid suspension, and in an injectable form.


Side Effects

Some of the most prevalent side effects caused by Pepcid are mentioned below. If these persist over time, then get them checked out by your doctor.

You may experience:

  • Headache
  • Dizziness
  • Confusion
  • Fluctuation in mood
  • Mouth dryness
  • Insomnia

Other symptoms can include:

  • Stomach pain
  • Diarrhea
  • Irregular bowel movement
  • Coughing
  • Difficulty swallowing
  • Nausea or vomiting

Pepcid consumption might lead to pain in the joints, fatigue, muscle pain, muscle cramps, and feeling weak.



Serious adverse effects can also be induced such as:

  • Pain in the abdomen
  • Blistering of skin
  • Irregular heartbeat
  • Wheezing
  • Chest tightness
  • Hallucinations
  • Runny nose
  • Issues urinating

Contact your medical advisor if you have any of these.

Allergic reactions are quite rare, but if you experience rashes on the skin, itchiness, swollen tongue and lips, difficulty breathing, and sore throat, then rush to the medical emergency room immediately.


How to Take?

Take medication exactly as prescribed by your doctor; Famotidine is taken 15 to 60 minutes prior a meal or a beverage to prevent heartburn. It is available in various forms; liquid solution (dosage once per day, or 2 to 4 times a day or before bedtime), tablets, capsules, and chewable tablets (usually consumed 2 times a day with a glass of water). Do not self-adjust the dosage and discontinue the medicine before the course ends. Refrain from taking over-the-counter meds for more than 2 weeks.


How does it work?

Histamine is a vital component of acid secretion inside the stomach. Inside the walls of our stomach, parietal cells exist which are responsible for releasing acid inside the stomach and this is where histamine performs its function by aiding these cells in doing their job. Since Pepcid is a Histamine-2 inhibitor; it binds with the histamine receptors present on the cells, preventing the real histamine substance to bind with the receptors. This way excess acid secretion stops.



Pregnant women often do suffer from acidic and digestive issues, but it’s still risky to use drugs while bearing an unborn fetus. Consult your doctor about this topic, get his/her advice and then take Pepcid if your doctor deems it okay.

Pepcid does dissolve into breast milk, so it’s a good idea to ask for your doctor’s opinion and be on the safe side rather than risking your infant’s health by taking it.

Inform your doctor about the past and present diseases so all potential threats can be ruled out before prescribing you the medicine. If you’ve had a history of kidney disease, liver problems, trouble with the immune system, stomach disorders, or lung diseases like asthma and COPD, then let your health advisor know so he/she can better understand on how to treat you better.

It is advised not to use H2 inhibitors such as Famotidine with proton inhibitors as both drugs will interact and decrease each other’s effectiveness. Pepcid can also render the absorption of other drugs like antifungals ineffective.