Famotidine

Famotidine is an active substance that is used to treat stomach and intestinal ulcers. It can also be used to treat Zollinger-Ellison syndrome. Famotidine is a thiazole derivative, belongs to the group of H2-receptor antagonists and prevents the release of the gastric enzyme pepsin and gastric acid. Famotidine has fewer drug interactions than cimetidine. Famotidine is available in medicines as a white-yellowish powder or as crystals.

Famotidine is a competitive histamine-2 (H2) receptor antagonist. This means that it blocks the H2 receptor (antagonist) as long as the concentration of famotidine is higher than that of the substances that normally bind to this receptor (competitive). It is used to inhibit the secretion of gastric acid and the enzyme pepsin. Famotidine has the advantage that it binds very specifically to the H2 receptor (selective) and therefore causes relatively few side effects. It is also stronger (more potent) than other drugs used for the same therapy.

Famotidine is mainly broken down via the liver, but is also excreted unchanged via the kidneys to a large extent. The bioavailability of famotidine - i.e. the percentage of the active ingredient available in the blood - is 40%. The half-life, i.e. the time the body needs to excrete half of the active substance, is approx. 3 hours. The maximum plasma concentration (Cmax), i.e. the maximum concentration of the active substance in the blood plasma (liquid cell-free part of the blood) is reached approx. 1-3.5 hours after ingestion.

Always take Famotidine exactly as described in the package leaflet or as advised by your doctor.

The usual recommended dose for adults and children aged 16 years and over is 10 mg - 160 mg daily, depending on the condition. The duration of use also depends on the disease and can last from a few weeks to several months.

The following side effects may occur:

Frequent:

• Headache
• dizziness
• constipation
• Diarrhea

Occasional:

• Taste disturbances
• Dry mouth
• Nausea and vomiting
• Gastrointestinal complaints
• Skin rashes
• itching
• Hives (urticaria)
• loss of appetite
• Tiredness

Rarely:

• Flatulence

Very rare:

• AV block (cardiac arrhythmia) with intravenous administration
• Severely reduced number of individual or all blood cells
• Cramps
• Paresthesia
• Drowsiness
• Pneumonia
• hair loss
• Severe skin and mucous membrane diseases with blistering
• Stevens-Johnson syndrome
• joint pain
• muscle cramps
• chest tightness
• hypersensitivity reactions
• Increased liver function values
• hepatitis
• jaundice
• impotence
• mental disorders
• sleep disorders
• Decreased sexual desire
• Growth of mammary glands in men (gynecomastia)
• palpitation (palpitations)
• fever
• bronchial asthma

Interactions may occur if the following medicines are taken at the same time:

• Calcium carbonate
• with medicines whose absorption depends on the acidity of the stomach
• when taking gastric acid-lowering agents (antacids), ketoconazole, itraconazole and sucralfate, the absorption of famotidine can be prevented and should therefore also be taken 2 hours apart from famotidine
• Probenecid can delay the excretion of famotidine and thus prolong its effect

Famotidine must NOT be taken in the following cases:

• if you are allergic to famotidine
• in case of previous hypersensitivity reactions to H2-receptor antagonists

Famotidine can be taken from the age of 16.

Famotidine can be taken during pregnancy. No harmful risk to the unborn baby has been shown in the 1st trimester of pregnancy. There is also no increased risk of harm in the 2nd and 3rd trimester of pregnancy.

Famotidine may be used during breastfeeding. A stimulating effect on prolactin production is being discussed, but this has neither been confirmed nor refuted to date. There are no reports of abnormalities in breastfed babies. Due to the low transfer rate into breast milk, no abnormalities are to be expected.