Cimetidine
TAGAMET
Pronunciation: sye-MET-i-deen
“Cy, Tag a Met”
Cimetidine (left) increases levels of metformin (Mr Met, right)
What it isH2 receptor antagonist suppressing gastric acid; GERD and ulcer disease.
Why this oneIts antiandrogen action can cause gynecomastia, a peculiar liability not shared by famotidine.
What limits itIt inhibits multiple CYP enzymes and tubular creatinine secretion, creating interactions and a false creatinine rise; famotidine has replaced it.
FDA-approved for
- ulcers (1977)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Heartburn relief (OTC) | Adults & children ≥12 yr | 200 mg (1 tablet) with water PRN | 200 mg PRN | 2 tablets/24h |
| Heartburn prevention (OTC) | Adults & children ≥12 yr | 200 mg (1 tablet) up to 30 min before trigger food/drink | 200 mg PRN | 2 tablets/24h |
Renal Undefined
Hepatic Undefined
Instructions
- Swallow 1 tablet with a glass of water
- For prevention, take right before or up to 30 minutes before eating/drinking trigger foods
- Do not take more than 2 tablets in 24 hours
- Children under 12 years: ask a doctor
Available strengths
- tab 200, 300, 400, 800 mg
- sol 300 mg/5 mL
Pregnancy Undefined
Lactation Undefined
Cost
Generic entry1994
NO BOXED WARNINGS
Principal riskInhibits four CYP enzymes; famotidine has replaced it
Classes and tags
Clinical profile
Legacy pregnancy categoryB
Defining liabilityLong-term infection, magnesium/B12 and bone risks; selected agents have clinically important CYP interactions.
Open Cimetidine in the interactive console ↗
Memory aids: interaction avatars
