What it is, what it does, and how much of it to take

Famotidine is a drug that prevents the stomach from producing acid.  

Powerful hydrochloric acid produced by your stomach aids in the digestion of food. Even when you're not eating, it continues to produce acid. Acid production is triggered by the mere sight, smell, or thought of food.  

Stomach acid production can be triggered by consuming certain foods and drinks, such as those that are high in caffeine, alcohol, or spicy flavors. The muscles that prevent acid from rising back up the esophagus are weakened by these causes as well. Having experienced the painful burning sensation of heartburn or acid reflux, many of us can say that we are all too familiar with this condition.  

When this uncomfortable sensation sets in, famotidine can be used to treat the symptoms.

A histamine-2 receptor antagonist, or H2-blocker, is what famotidine is.  

H2-blockers work by blocking the action of histamine H2 receptors in the stomach. Blocking H2-receptors reduces gastric acid production.  

People with stomach-related conditions, such as chronic heartburn, GERD, ulcers, and more, should pay special attention to controlling stomach acid production. Different strengths of famotidine are marketed under different brand names, such as Pepcid, Pepcid AC, and Zantac 360.

U.S. authorities have given their stamp of approval to the drug famotidine. S Approved by the Food and Drug Administration (FDA) for the following disorders (FDA, 2018)

• Heartburn is a common symptom of acid reflux, which occurs when stomach acid flows backward through the esophagus and into the food pipe. By neutralizing stomach acid, famotidine provides relief from reflux (also known as GERD or gastroesophageal reflux disease) symptoms.
• Too much acid in the stomach can eat away at the stomach and intestinal lining, resulting in ulcers (also known as peptic ulcer disease). Famotidine is helpful in treating both stomach and duodenal ulcers.
• Esophagitis: Esophagus lining inflammation brought on by GERD's chronic irritation. With regular use, famotidine can reduce acid production in the esophagus, relieving symptoms like heartburn that can accompany the condition.  
• In the extremely rare condition known as Zollinger-Ellison syndrome, excessive stomach acid causes ulcers to form all along the digestive tract. Famotidine is an effective treatment for the symptoms of this unusual condition because it inhibits the production of acid.  

Off-label uses of famotidine are common. Off-label medications are those that have not been approved by the Food and Drug Administration (FDA) to treat a particular condition, but are still prescribed by doctors. Uses of famotidine that aren't approved by the FDA include:

• Pain relievers like aspirin and ibuprofen fall into the category of non-steroidal anti-inflammatory drugs (NSAIDs), which can cause a variety of side effects, including irritation. Long-term use of these medications can cause irritation of the stomach lining and ulcers. (Deeks, 2013)   
• Ulcers caused by stress also have significant physiological effects. Patients in intensive care units (ICUs) are at increased risk for developing stomach ulcers, according to studies. Off-label, famotidine use for ulcer prevention in these patients  
• Treatment for COVID-19 includes the use of famotidine in addition to antiviral drugs. The results of one clinical trial support the idea that this mixture reduces the danger of serious illness and death (Mather, 2020).   

Generally speaking, famotidine is a safe and well-tolerated drug. Famotidine can cause nausea, vomiting, stomach pain, and diarrhea or constipation (FDA, 2018).

Although serious adverse effects are uncommon, here are a few to watch out for:

• Infection in children: Young people taking proton pump inhibitors like famotidine may be more susceptible to gastrointestinal viruses and pneumococcal pneumonia (lung infections) (Canani, 2006).  
• People who take famotidine are more likely to contract an intestinal infection caused by Clostridium difficile (Nath, 1994).  
• Side effects on the nervous system include things like epileptic seizures brought on by the use of H2-blockers like famotidine (Cannon, 2004).  
• Arrhythmias (abnormal heart rhythms), such as long-QT syndrome, are more common in people who take H2-blockers (Yun, 2015).  
• However uncommon, liver damage has been linked to the use of all H2-blockers. Compared to other H2-blockers, famotidine rarely causes liver problems.  

Famotidine tablets and liquids in 10, 20, and 40 milligram strengths can be purchased without a prescription. Pepcid Complete, a chewable combination with antacids like calcium, is also available.  

Some medical centers even offer IV famotidine solutions for patients.  

Initial famotidine dosing for people with acute (sudden, short-term) acid reflux is typically 10-20 mg once daily. The standard starting dose for GERD sufferers is 20 mg taken before bed. If your doctor suspects you have a condition like ulcers or esophagitis, he or she may suggest a higher dose.  

You should talk to your doctor before taking famotidine, as it isn't intended for prolonged use.  

You are not imagining things if you experience more severe acid reflux symptoms while lying down at night; there are actual physiological causes for this.  

Late at night, your stomach produces more acid, and when you lie flat in bed, that acid has an easier time making its way to your esophagus. To avoid this, many doctors suggest taking famotidine or another acid reducer before bed (Voigt, 2019).

The mechanism of action of H2-blockers makes it possible for them to alter the concentration of other medications you take, increasing the risk of unwanted effects.  

Famotidine has a lower incidence of this problem than other H2-blockers, but it can still affect the metabolism of drugs like:

When taking famotidine, these groups of people are more likely to experience unwanted side effects:

• Avoid taking famotidine if you have ever had an allergic reaction to H2-blockers or any other similar medications.  
• People with specific symptoms: See a doctor before starting famotidine if you have chest pain, wheezing, bloody stool, or sudden, significant weight loss that you cannot account for.  
• Famotidine is metabolized and filtered by the liver and kidneys, respectively; therefore, those with preexisting liver or kidney disease may not be able to safely take the drug. Before starting any new medication, it's important to talk to your doctor.  

Research indicates that famotidine poses no threat to the developing fetus. There is currently no evidence suggesting it causes infant mortality, premature birth, or negative effects during pregnancy (Matok, 2010).  

Infants who are breastfed are safe to take famotidine because they receive less than the recommended dosage (less than 2% of what is in breast milk) (LactMed, 2021). Safe medication use during pregnancy and breastfeeding can be discussed with your doctor.  

Talk to your doctor or pharmacist if you have any concerns or questions about famotidine, including its intended use and proper dosing.

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