Cimetidine
Cimetidine Uses, Dosage, Side Effects, Food Interaction and all others data.
Cimetidine competitively inhibits histamine at H2-receptors of the gastric parietal cells resulting in decreased gastric acid secretion, gastric volume and hydrogen ion concentration. It is also used in patients with pancreatic insufficiency to reduce the breakdown of pancreatic enzyme supplements.
Cimetidine is a histamine H2-receptor antagonist. It reduces basal and nocturnal gastric acid secretion and a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli including food, caffeine, insulin, betazole, or pentagastrin. It is used to treat gastrointestinal disorders such as gastric or duodenal ulcer, gastroesophageal reflux disease, and pathological hypersecretory conditions. Cimetidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system. Other actions of Cimetidine include an increase in gastric bacterial flora such as nitrate-reducing organisms.
| Trade Name | Cimetidine |
| Availability | Rx and/or OTC |
| Generic | Cimetidine |
| Cimetidine Other Names | Cimetidin, Cimetidina, Cimétidine, Cimetidine, Cimetidinum |
| Related Drugs | omeprazole, famotidine, pantoprazole, Nexium, Pepcid, Protonix, esomeprazole, sucralfate, Prilosec, ranitidine |
| Weight | 200mg, , 300mg/5ml, 300mg, 400mg, 800mg |
| Type | Tablet, Tablets, Oral Liquid, Oral Tablet, Injection, Solution |
| Formula | C10H16N6S |
| Weight | Average: 252.339 Monoisotopic: 252.115715232 |
| Protein binding | In humans, approximately 22.5% of cimetidine is plasma protein bound. |
| Groups | Approved, Investigational |
| Therapeutic Class | H2 receptor antagonist |
| Manufacturer | Nawabsons Laboratories (pvt) Ltd, , Accord Healthcare Limited, Ennogen Pharma Ltd, Frendun Pharmaceuticals Ltd, Jiangsu Ruinan Qianjin Pharmaceutical Company Limited, Huangshan Shengji Pharmaceutical Co Limited, Jay Formulations Limited |
| Available Country | Pakistan, United Kingdom, Canada, United States, India, Nigeria, China |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Benign gastric and duodenal ulceration, GERD, Zollinger-Ellison syndrome, Prophylaxis of GI haemorrhage from stress ulceration, Prophylaxis of acid aspiration during general anesthesia, Non-ulcer dyspepsia, Prophylaxis of nocturnal heartburn, Short bowel syndrome, Pancreatic insufficiency, Benign gastric and duodenal ulceration, Zollinger-Ellison syndrome Intermittent infusion
Cimetidine is also used to associated treatment for these conditions: Cystic Fibrosis (CF), Gastric hypersecretion, Gastro-esophageal Reflux Disease (GERD), Gastrointestinal Symptoms, Heartburn, NSAID Associated Gastric Ulcers, Active Duodenal ulcer, Benign gastric ulcers, Recurrent Ulcers, Duodenal and Gastric
How Cimetidine works
Cimetidine binds to an H2-receptor located on the basolateral membrane of the gastric parietal cell, blocking histamine effects. This competitive inhibition results in reduced gastric acid secretion and a reduction in gastric volume and acidity.
Dosage
Cimetidine dosage
Benign gastric and duodenal ulceration: 800 mg daily at bedtime or 400 mg bid for at least 4 wk (duodenal ulcer), 6 wk (gastric ulcer) and 8 wk (NSAID-associated ulcer). Maintenance: 400 mg daily at bedtime or bid.
GERD: 400 mg 4 times/day or 800 mg bid for 4-12 wk.
Zollinger-Ellison syndrome: 300 or 400 mg 4 times/day.
Prophylaxis of GI haemorrhage from stress ulceration: 200-400 mg 4-6 hrly.
Prophylaxis of acid aspiration during general anaesth: 400 mg 90-120 min before induction of anaesth up to 400 mg 4 hrly if needed.
Non-ulcer dyspepsia: Max: 800 mg/day in divided doses.
Prophylaxis of nocturnal heartburn: 100 mg at bedtime.
Short bowel syndrome: Initial: 400 mg bid, adjusted according to response.
Pancreatic insufficiency: 800-1600 mg/day in 4 divided doses. IV
Benign gastric and duodenal ulceration; Zollinger-Ellison syndrome Intermittent infusion: 300 mg 6-8 hrly infused over 15-20 min. Max: 2400 mg/day.
Continuous infusion: 37.5 mg/hr (900 mg/day). A 150 mg IV loading dose may be given in patients requiring rapid elevation of gastric pH.
Should be taken with food.
Side Effects
Diarrhoea, other GI disturbances, dizziness, headache, tiredness, myalgia, arthralgia, rashes, altered LFTs, reversible confusional states. Rarely, hypersensitivity reactions and fever, reversible alopecia, blood disorders (e.g. agranulocytosis, leucopenia, and thrombocytopenia), acute pancreatitis, interstitial nephritis, hallucinations and depression, CV disorders (e.g. bradycardia, tachycardia, heart block), transient hypotension, gynaecomastia and impotence.
Toxicity
In the rare event of cimetidine overdose, it is vital to maintain the airway and cardiovascular status. The patient should be closely monitored and provided with symptomatic and supportive treatment as needed. Interventions such as gastric lavage and administration of activated charcoal may be initiated if deemed appropriate and necessary.
Precaution
History of peptic ulcer. Increased risk of developing community-acquired pneumonia in the elderly, patients with chronic lung disease, DM, or the immunocompromised. Increased possibility of a hyperinfection caused by Strongyloides stercoralis in immunocompromised patients. Possibility of malignancy should be excluded prior to therapy as the drug may mask symptoms and delay diagnosis of gastric malignancy. Avoid rapid IV inj. Renal and hepatic impairment. Pregnancy and lactation.
Interaction
Reduces absorption of dasatinib, ketoconazole, itraconazole and posaconazole. May increase serum levels of phenytoin, theophylline, lidocaine, hydroxyzine and oral anticoagulants. Absorption may be reduced by antacids. Decreased bioavailability with metoclopramide, sucralfate or propantheline. May potentiate the myelosuppressive effects (e.g. agranulocytosis, neutropenia) of myelosuppressive drugs (e.g. antimetabolites, alkylating agents) or therapies (e.g. radiation).
Food Interaction
- Take with food. Food increases bioavailability. For prophylaxis of gastric symptoms, take cimetidine 30-60 minutes prior to food administration.
Cimetidine Alcohol interaction
[Minor] Concurrent use of cimetidine and ethanol may result in increased ethanol concentrations.
The mechanism appears to be due to inhibition of gastric alcohol dehydrogenase by cimetidine, leading to increased bioavailability of the alcohol and inhibition of hepatic metabolism of alcohol.
The clinical significance of this interaction is limited.
More importantly, patients requiring cimetidine for gastrointestinal disease should be counseled to avoid alcohol to prevent worsening of their disease.
The other H-2 receptor antagonists appear to have minimal effects on the concentrations of alcohol.
Cimetidine Drug Interaction
Moderate: duloxetine, duloxetineMinor: acetaminophen, acetaminophen, cyanocobalamin, cyanocobalamin, cholecalciferol, cholecalciferolUnknown: aspirin, aspirin, diphenhydramine, diphenhydramine, omega-3 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, pregabalin, pregabalin, ascorbic acid, ascorbic acid, cetirizine, cetirizine
Cimetidine Disease Interaction
Major: liver disease, GI bleedingModerate: hemodialysis, renal dysfunction
Volume of Distribution
The volume of distribution of cimetidine is reported to be 1 L/kg.
Elimination Route
Two peak plasma concentrations are often observed after oral administration of cimetidine, likely as a result of discontinuous absorption in the gastrointestinal tract. In healthy patients, the absolute bioavailability of cimetidine is approximately 60%; however, the bioavailability can be as high as 70% in patients with peptic ulcer disease. Overall, rates of bioavailability are much more variable in patients with peptic ulcer disease.
Half Life
Cimetidine's half-life is estimated to be around 2 hours.
Clearance
Cimetidine's reported systemic clearance value is approximately 500-600 ml/min.
Elimination Route
Cimetidine is excreted primarily in the urine.
Pregnancy & Breastfeeding use
Pregnancy Category B. Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).
Contraindication
Cimetidine is contraindicated in any patient hypersensitive to the drug or its components.
Acute Overdose
Symptoms: Dizziness, bradycardia, CNS depression, vomiting.
Management: Induce vomiting and/or gastric lavage, followed by symptomatic and supportive treatment.
Storage Condition
Store between 16-30°C. Protect from light.
Innovators Monograph
You find simplified version here Cimetidine
FAQ
What Cimetidine is used for?
Cimetidine is used to treat ulcers,gastroesophageal reflux disease (GERD), a condition in which backward flow of acid from the stomach causes heartburn and injury of the food pipe (esophagus); and conditions where the stomach produces too much acid.
How safe is Cimetidine?
Cimetidine is approved by the U.S. Food and Drug Administration and is safe and effective when used according to the Drug Facts label.
How does Cimetidine work?
Cimetidine works by reducing the amount of acid in your stomach.
What are the common side effects of Cimetidine?
Common side effects of Cimetidine are include:
- headache.
- diarrhea.
- dizziness.
- drowsiness.
- breast enlargement.
Is Cimetidine safe during pregnancy?
A study on the safety of Cimetidine suggests that pregnant women taking these drugs from the first trimester through their entire pregnancy have delivered normal babies.
Is Cimetidine safe during breastfeeding?
Cimetidine treatment for heart burn and acid indigestion, is another non-prescription drug to avoid while breastfeeding.
Can I drink alcohol with Cimetidine?
Talk to your doctor before consuming alcohol while taking Cimetidine. Using Cimetidine and alcohol together may increase the effects of alcohol, leading to increased drowsiness and dizziness.
When is the best time to take Cimetidine?
Cimetidine is usually taken once a day at bedtime or two to four times a day with meals and at bedtime. Over the counter Cimetidine is usually taken once or twice a day with a glass of water. To prevent symptoms, it is taken within 30 minutes before eating or drinking foods that cause heartburn.
How long does Cimetidine stay in my system?
Cimetidine is rapidly eliminated, with an elimination half-life of 123 minutes, or about 2 hours. It has been said to have a duration of action of 4 to 8 hours.
Can I take Cimetidine for a long time?
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.
Does Cimetidine heal esophagus?
Cimetidine 800 mg twice daily, is effective in promoting healing of esophageal ulcers and erosions and in providing heartburn relief in patients with symptomatic erosive.
How much Cimetidine can I take in a day?
Do not take more than 2 tablets in 24 hours unless directed by your doctor. Do not take for more than 14 days in a row without talking with your doctor.
Does Cimetidine raise blood pressure?
Cimetidine increased the blood pressure and heart rate.
Does Cimetidine affect the heart?
The results showed a statistically significant reduction only in heart frequency, triple product and cardiac output of subjects treated with Cimetidine; no modifications were observed in subjects treated with placebo. It is concluded that Cimetidine changes in heart frequency and its related parameters.
Who should not take Cimetidine?
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
What happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
Does Cimetidine cause cancer?
We observed no trend in risk of breast cancer according to time since first or last Cimetidine prescription or number of Cimetidine prescriptions filled.
How much Cimetidine can I take?
The usual dosage is 400mg twice a day, with breakfast and at bedtime. For patients with duodenal or benign gastric ulceration, a single daily dose of 800mg at bedtime is recommended.
Can I just stop taking Cimetidine?
You can stop taking the over the counter heartburn Cimetidine when your symptoms of acid indigestion, sour stomach and heartburn no longer require its use.
Can I take too much Cimetidine?
If you take too much Cimetidine, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away. If Cimetidine is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur.
