Cimetidine is a histamine H2 receptor blocker that suppresses stomach acid production. It is used in the short-term treatment of duodenal and peptic ulcers, as well as in over-the-counter formulations to prevent heartburn or acid indigestion.
The drug effectively regulates gastric hypersecretion and is also used to treat reflux esophagitis and prevent stress-related stomach ulcers.
What Is Cimetidine?
Cimetidine is an H2 receptor blocker that is used to treat heartburn, peptic ulcer disease & gastroesophageal reflux disease. It is available in tablet form & injectable forms. It is sold under the brand names Tagamet & Tagamet Hb
Cimetidine Mechanism Of Action
Cimetidine Available Strengths
Cimetidine is available in 2 strengths
Cimetidine......... 200mg
Cimetidine................ 400mg
In Tablet and injectable forms
Cimetidine Uses Or Indications
Cimetidine works by inhibiting the production of stomach acid and is used to treat:
- Heartburn
- Peptic ulcers
- Reflux Esophagitis
- Prevention of stress-related gastric ulcers
Cimetidine Contraindications.
The following are the Cimetidine Contraindications:
- Blood in your stools (black or tarry stools) or if you have blood in your vomiting
- Kidney disease
- Liver disease
- Pain or trouble trying to swallow food
- An unusual or allergic reaction to cimetidine
- Previous history of allergies with H2 receptor blocker
Cimetidine Dosage and Administration
Administration
Once or twice daily according to your Physician’s instructions 15-30 minutes before meals or at bedtime.
Dosage For Adults
Adult Dose for Heartburn
Adult Dose for Erosive Esophagitis
Adult dose for GERD
Adult Dose for Gastric Ulcers
Adult Dose for Duodenal Ulcer
For Prophylaxis of Duodenal ulcers
Missed Dose
Take the missed dose of this medication as soon as you remember. If your next dose is approaching, skip the missed one and resume your regular dosing regimen. Avoid doubling the doses.
Cimetidine Use During Pregnancy And Breastfeeding.
Pregnancy
Cimetidine Pregnancy Category
Category B
If you are pregnant, do not take this medication unless it is strictly required or recommended by a health care professional.
Lactation
Cimetidine is unlikely to affect breastfed babies, especially if they are over 2 months old. However, due to its potential to inhibit liver enzymes, other medications may be more suitable.
Cimetidine Alternatives That Are Safe
- Famotidine
- Omeprazole
- Pantoprazole
- Sucralfate
Cimetidine Side Effects
- Constipation
- Diarrhea
- Dizziness
- Headache
- Allergic reactions such as skin rash, itching &hives.
Cimetidine Interactions
- Cisapride
- Dofetilide
- Pimozide
- Caffeine
- Carbamazepine
- Carmustine
- Delavirdine
- Female hormones, including contraceptive or birth control pills
- Itraconazole
- Ketoconazole
- Medications for heart rhythm problems
- Phenytoin
- Theophylline
- Warfarin
Pro Advice 💡
In case of heartburn, indigestion, and reflux here are some informational tips for you.
- Avoid lying down for three hours after a meal.
- Eat smaller meals more frequently throughout the day.
- Wear loose-fitting clothing to avoid pressure on your abdomen.
- Lose excess weight
- Quit smoking
- Elevate Your head while sleeping
Several types of food can cause acid reflux and heartburn avoid these foods.
- Fatty or fried foods
- Alcohol
- Coffee
- Carbonated beverages, such as soda
- Chocolate
- Garlic
- Onions
- Citrus fruits
- Tomato sauce
Cimetidine Brand Names
FAQs
Q1. What is Cimetidine used for?
Ans. Cimetidine is used for the treatment of
- Heartburn
- Peptic ulcers
- Reflux Esophagitis
- Prevention of stress-related gastric ulcers
Q2. Is Cimetidine an H2 Blocker?
Ans. Yes, Cimetidine is an H2 blocker but with a shorter duration of action that's why Famotidine is used mostly due to its longer duration of action for heartburn and peptic ulcer treatment.
Q3. What class of drug is Cimetidine
Ans. Cimetidine belongs to the H2 receptor blocker class of drugs.
Q4. What are some serious side effects of cimetidine?
Ans. Some side effects of cimetidine are
- Nausea or vomiting regularly
- Changes in mood or emotions (e.g., agitation, depression, hallucination)
- Problems with urination
- Musculoskeletal or joint pain
- Breast enlargement in men
- Lack of sexual function
Q5. Which enzyme is inhibited by cimetidine?
Ans. Cimetidine is an inhibitor of hepatic cytochrome P450 (CYP) enzyme system
Q6. What is the maximum daily dose of Cimetidine?
Ans. The maximum daily dose of Cimetidine is 2.4g/day.
Q7. Is Cimetidine safe for kids?
Ans. Cimetidine therapy is often not advised for pediatric patients under the age of 16 years. For newborns and young children, other H2 antagonists like famotidine might be preferable.
Q8. What is the dose of Cimetidine in children?
Ans. The dose of Cimetidine in children from the newborn period up to the age of 18 years is as follows
Newborn
5-10 mg/kg per day orally in 3 divided doses.
1month to 1 year
10-20 mg/kg per day orally in 2 divided doses.
1 year to 18 years
20-40 mg/kg per day orally in 4 divided doses. Max: 1600 mg/day.
Q9. Is Cimetidine used for h pylori?
Ans. When PPIs (Proton Pump Inhibitor) are not effective for treating H. pylori infection then histamine (H-2) blockers are the next best option.
Q10. Can babies have cimetidine?
Ans. Cimetidine is unlikely to have any negative effects in breastfed newborns, especially if the infant is older than 2 months.
Q11. Can cimetidine be given intramuscularly?
Ans. Yes, as written on the label, cimetidine injection can be administered intramuscularly without dilution.
Q12. When is cimetidine given before surgery?
Ans. Cimetidine 300 mg orally 2 hours before intubation or 45-60 minutes IV given before the operation to reduce the gastric acidity below the threshold level.
Q13. Can cimetidine be given IV?
Ans. The medicine can also be given intravenously (IV) as a parenteral injection.
Q14. Is cimetidine safe for the elderly?
Ans. Cimetidine can result in mental confusion and should be used with caution and at lower doses in patients with hepatic or renal diseases and elderly people.
Q15. Does cimetidine make you sleepy?
Ans. Yes, one of the adverse effects of cimetidine is somnolence.
Q16. Does cimetidine cause breast growth?
Ans. According to the study after more than four months of treatment with cimetidine i.e. 1.6 g daily, five out of 25 male duodenal ulcer patients developed unilateral or bilateral gynecomastia.
Q17. Does cimetidine cause weight gain?
Ans. Cimetidine may cause loss of appetite, reduce food intake, and result in weight loss but not weight gain
Q18. What nutrient is lost when cimetidine is taken?
Ans. Cimetidine, which decreases stomach acid, may decrease the absorption of vitamin B12 levels.
Q19. Does cimetidine cause hair loss?
Ans. Cimetidine (Tagamet), ranitidine (Zantac), and famotidine are examples of antiulcer medications that can cause alopecia (hair loss).
Q20. What is the half-life of cimetidine?
Ans. The half-life of cimetidine is estimated to be roughly 2 hours and mostly eliminated in the urine.
Q21. Where is cimetidine metabolized?
Ans. Cimetidine is partially metabolized by the liver, and to a larger amount when it is taken orally.
References
Cimetidine: Uses & Side Effect | Cleveland Clinic [Internet]. my.clevelandclinic.org/ [Last accessed 15 September 2023].
Disclaimer
All information on the product's uses, dosage, side effects, formula, ingredients, indications, contraindications, drug interactions, warnings and precautions, and whether it is safe to use during pregnancy and breastfeeding is based solely on material found on the internet. It's only provided here for general education and information purposes.
We can not guarantee the accuracy of any of the information we publish on this website. All of the information material we published is based only on FDA-approved literature and is not intended to replace expert medical advice. Always seek expert medical advice from a healthcare provider before starting to use this medicine.
Dr. Mohd Kamran Karim
I am a professional doctor and an enthusiastic blogger who completed his graduation in 2013 (MBBS) and currently working as a post graduate clinical fellow. I am a medical professional with desired clinical expertise, and I want to utilize my knowledge & writing to advise my readers on how to use prescription and over-the-counter medications to minimize any adverse effects.