Famotidine: What it is used for, how and when to use it

belonging to the class of histamine H2 receptor antagonists.

Shutterstock Famotidine - Chemical Structure

It is used in the treatment of all those disorders connected to stomach acid hypersecretion. Compared to the progenitor of histamine H2 receptor antagonists - cimetidine - this active principle is much more powerful (about 30 times as much); moreover, again compared to cimetidine, famotidine does not interfere with the action of cytochrome P450, with a consequent reduction in possible interactions with other drugs.

Taken orally, famotidine is now available in a single drug (Famotidina EG®) for which the presentation of a special repeatable medical prescription (RR) is required. However, it is a Class A drug whose price can be - in the foreseen cases - partially reimbursed by the National Health System (the payment of a ticket by the patient is required).

;

Mild to moderate inflammation of the esophagus;

Gastric ulcer;

Duodenal ulcer;

Zollinger-Ellison syndrome.

Famotidine is also used in the preventive treatment of recurrent duodenal ulcers.

is compromised;

You suffer from mild gastrointestinal disorders;

You are taking atazanavir for the treatment of HIV infection.

The doctor should also be informed immediately if the following symptoms occur, both before and while taking famotidine:

Unintentional loss of body weight
Difficulty swallowing
Repeated vomiting
Hematemesis;
Anemia;
Blood in the stool.

These symptoms, in fact, could be attributable to the presence of stomach cancer, famotidine can mask the symptoms of the aforementioned tumor thus delaying the diagnosis. Therefore, if symptoms persist, worsen or change, the doctor should be warned so that he can carry out further investigations.

Furthermore, in patients suffering from gastric or duodenal ulcer, the doctor may decide to carry out analyzes and tests to identify the possible presence of Helicobacter pylori.

(OTC), herbal and phytotherapeutic products, homeopathic products, etc.

However, famotidine should not be taken if you are already taking:

Probenecid (used to fight gout);
Medicines to treat HIV infection such as atazanavir, tenofovir and ritonavir.

The following drugs, on the other hand, can reduce the effect of famotidine, so they should be taken at least two hours later the latter:

Antacids;
Sucralfate.

Finally, please note that famotidine can reduce the effect of:

Azole antifungals such as ketoconazole and itraconazole;
Atazanavir combined with ritonavir.

, manifesting undesirable effects different in type and intensity, or not manifesting them at all.

Common side effects

Among the side effects that can commonly arise during treatment with famotidine, we mention:

Headache
Dizziness
Constipation or diarrhea.

Uncommon side effects

Among the undesirable effects that may occur less commonly during the course of treatment, however, we find:

Nausea and / or vomiting;
Gastrointestinal disorders;
Flatulence;
Dry mouth
Loss of appetite
Skin rashes and itching;
Fatigue.

Rare side effects

Among the side effects that may occur more rarely during famotidine therapy, we find:

Severe allergic / hypersensitivity reactions resulting in difficulty in breathing or dizziness (anaphylaxis), angioedema, difficulty in breathing or wheezing;
Jaundice secondary to intrahepatic cholestasis;
Urticaria;
Arthralgia;
Increased laboratory values (transaminases, gamma GT, alkaline phosphatase, bilirubin).

Very rare side effects

On the other hand, the following undesirable effects are very rare:

Pancytopenia, leukopenia, agranulocytosis, thrombocytopenia (may manifest with symptoms such as weakness, fatigue, sudden fever, sore throat, bruising or nosebleed);
Hallucinations, disorientation, confusion, anxiety, agitation, depression;
Paresthesia;
Drowsiness;
Insomnia;
Seizures;
Alopecia;
Severe skin reactions, such as toxic epidermal necrolysis;
Impotence;
Reduction of libido;
Sense of chest tightness.

Famotidine overdose

Although there have been no reported cases of famotidine overdose to date, in case of overdose of the drug, you should contact your doctor immediately.

histamine. In this way, stomach acid secretion - both basal and food-induced - is inhibited. We remember, in fact, that through the activation of its H2 receptors, histamine promotes the production of gastric acids.

: 20 mg of famotidine twice a day.

Treatment of mild to moderate inflammation of the esophagus: 40 mg of famotidine twice a day.

Benign gastric ulcers and duodenal ulcers: 40 mg of famotidine, in the evening before bedtime. Treatment should be continued for 4-8 weeks. However, this term may be shortened if the doctor believes that the ulcer has healed following confirmation after endoscopic examination. If the examination shows that the ulcer has not healed, treatment should be continued for another 4 weeks.

Prevention of recurrent duodenal ulcers: 20 mg of famotidine in the evening. The recommended maintenance dose of 20 mg was administered continuously and effectively in clinical trials lasting 12 months.

Zollinger-Ellison syndrome: in the absence of previous therapy, treatment begins with 20 mg of famotidine to be administered at 6 hour intervals. Depending on the acid secretion and the patient's response to therapy, the doctor may increase the dose and continue the treatment until the desired effect is achieved. If the administration of a daily dosage of up to 800 mg fails, the doctor may consider alternative treatment.If the patient has had previous treatment with similar medicines (eg other histamine H2-receptor antagonists), famotidine therapy may be started at a higher dosage than is usually recommended.

In patients with impaired renal function, the doctor may decide to administer lower doses of famotidine than those usually used.

for this reason, if treatment with this active ingredient is necessary, breastfeeding should be stopped.