cimetidine vs risperidone
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Side-by-side comparison of cimetidine and risperidone. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
major Known Drug Interaction
Dose adjustment is not recommended for risperidone tablets when co-administered with ranitidine, cimetidine, amitriptyline, or erythromycin [see Table 18 ] . Do not exceed twice the patient’s usual dose Enzyme (CYP3A) inhibitors Ranitidine 150 mg twice daily 1 mg single dose 1.2 1.4 Dose adjustment not needed Cimetidine 400 mg twice daily 1 mg single dose 1.1 1.3 Dose adjustment not needed Erythromycin 500 mg four times daily 1 mg single dose 1.1 0.94 Dose adjustment not needed Other Drugs Amitriptyline 50 mg twice daily 3 mg twice daily 1.2 1.1 Dose adjustment not Needed *Change relative...
Tagamet
Risperdal
Cimetidine (Tagamet) reduces stomach acid. It is used to treat ulcers, heartburn, and other conditions where too much acid is produced.
Risperidone is a medicine used to treat certain mental disorders. It can help reduce symptoms like hallucinations, delusions, and aggression.
Cimetidine treats active duodenal ulcers for short periods. It can also be used long-term at a lower dose to prevent ulcers from returning. This medicine also treats active benign gastric ulcers for a short time. Additionally, it can help with erosive gastroesophageal reflux disease (GERD), which damages the esophagus.
Risperidone is used to treat schizophrenia in adults and teens. It also treats manic or mixed episodes of bipolar I disorder, either alone or with lithium or valproate. Additionally, it can help with irritability, including aggression and self-injury, in children and teens with autism.
Cimetidine is an H2 receptor antagonist. This means it blocks histamine from attaching to certain cells in your stomach. By blocking histamine, cimetidine reduces the amount of acid your stomach makes.
Risperidone works by changing the levels of certain natural substances in the brain. These substances are called neurotransmitters. By balancing these chemicals, risperidone can reduce symptoms of mental disorders.
- • Headache
- • Dizziness
- • Diarrhea
- • Parkinsonism (slowed movement, stiffness)
- • Restlessness
- • Muscle stiffness or spasms
- • Tremors
- • Sleepiness
- Chronic Kidney Disease 1,264
- Acute Kidney Injury 710
- Renal Failure 694
- Nausea 681
- Fatigue 598
- Gynaecomastia 24,608
- Abnormal Weight Gain 9,446
- Weight Increased 9,088
- Emotional Disorder 5,947
- Injury 4,623
Reversible confusional states (like mental confusion, agitation, or hallucinations) have been reported, mostly in severely ill patients. These usually appear within 2-3 days of starting treatment and clear up within 3-4 days of stopping the drug.
Risperidone may increase the risk of death in elderly patients who have dementia-related psychosis. Risperidone is not approved for treating dementia-related psychosis.
Tell your doctor if you are pregnant or plan to become pregnant. The effects of cimetidine during pregnancy are not fully known. Talk to your doctor about the risks and benefits of taking cimetidine while breastfeeding.
Tell your doctor if you are pregnant or plan to become pregnant. Babies born to mothers who take risperidone in the last 3 months of pregnancy may have withdrawal symptoms or other problems after birth. There is a pregnancy registry to monitor outcomes in women exposed to risperidone during pregnancy. You can contact the registry at 1-866-961-2388.
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How to Read This cimetidine vs risperidone Comparison
cimetidine is classified in the H2 Receptor Antagonist drug class, while risperidone sits within the Atypical Antipsychotic class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are split between OTC and prescription status, which affects access and supervision.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, cimetidine has 3,947 submissions while risperidone has 53,712. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known major interaction flagged in FDA labeling, attributed to cimetidine can slightly slow down the enzymes that break down risperidone, but the effect is very small.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for cimetidine or risperidone.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.