Table of Contents
What is the mechanism of action of cimetidine?
Mechanism of Action The H2-receptor antagonist cimetidine competitively blocks histamine from stimulating the H2-receptors located on the gastric parietal cells (these cells are responsible for hydrochloric acid secretion and secretion of the intrinsic factor).
How does histamine agonist work?
Drugs that bind to and activate histamine receptors. Although they have been suggested for a variety of clinical applications histamine agonists have so far been more widely used in research than therapeutically. For use clinically to test gastric secretory function.
Why is cimetidine used less frequently?
The development of longer-acting H2 receptor antagonists with fewer drug interactions and adverse effects, such as ranitidine and famotidine, decreased the use of cimetidine, and though it is still used, cimetidine is no longer among the more widely used of the H2 receptor antagonists.
What kind of inhibitor is cimetidine?
Cimetidine is an inhibitor of hepatic cytochrome P450 (CYP) in vivo and in vitro in both rats and humans. However, the concentrations of cimetidine required to inhibit drug metabolism in hepatic microsomes in vitro are 100-1000-fold higher than those associated with a similar degree of inhibition in vivo.
What is cimetidine side effects?
Common side effects of cimetidine include:
- headache.
- dizziness.
- sleepiness.
- enlarged breasts in men.
- confusion (elderly)
- impotence.
- diarrhea.
- nausea.
What is the drug cimetidine used for?
Over-the-counter cimetidine is used to prevent and treat symptoms of heartburn associated with acid indigestion and sour stomach. Cimetidine is in a class of medications called H2 blockers.
What is the use of histamine?
Histamine is an important chemical that has a role in a number of different bodily processes. It stimulates gastric acid secretion, plays a role in inflammation, dilates blood vessels, affects muscle contractions in the intestines and lungs and affects your heart rate.
What is the side effect of cimetidine?
Headache, dizziness, drowsiness, or diarrhea may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. If your doctor has directed you to use this medication, remember that your doctor has judged that the benefit to you is greater than the risk of side effects.
How fast does cimetidine work?
Cimetidine is rapidly and virtually completely absorbed from the gastro-intestinal tract. Absorption is little impaired by food or by antacids. Peak plasma concentrations are obtained about an hour after administration on an empty stomach, and about 2 hours after administration with food.
Is cimetidine safe?
Cimetidine is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label.
Does cimetidine make you sleepy?
What type of drug is histamine?
When histamine, a chemical created by your immune system, overreacts to an allergen such as pollen and pet dander, it can cause symptoms such as coughing, sneezing and watery eyes. Antihistamines are medications that help with allergies, and also with stomach problems, cold, anxiety and more.
Is histamine a drug?
Histamine is an ingredient of topical drugs for the relief of joint pain or muscle aches and pains. A depressor amine derived by enzymatic decarboxylation of histidine. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.
What are the side effects of histamine?
The histamine causes an allergic reaction with unpleasant symptoms including itchy, watering eyes, a running or blocked nose, sneezing and skin rashes.
Does cimetidine cure ulcer?
CIMETIDINE (sye MET i deen) is a type of antihistamine that blocks the release of stomach acid. It is used to treat stomach or intestinal ulcers. It can relieve ulcer pain and discomfort, and the heartburn from acid reflux.
Is cimetidine safe to take?
Do not take over-the-counter cimetidine for longer than 2 weeks unless your doctor tells you to. If symptoms of heartburn, acid indigestion, or sour stomach last longer than 2 weeks, stop taking cimetidine and call your doctor.
What is the main side effect of antihistamines?
Some of the common side effects of first-generation antihistamines include: Drowsiness. Dry mouth, dry eyes. Blurred or double vision.