cimetidine vs hydroxychloroquine
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Side-by-side comparison of cimetidine and hydroxychloroquine. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
moderate Known Drug Interaction
7.8 Cimetidine Concomitant use of cimetidine resulted in a 2-fold increase of exposure of chloroquine, which is structurally related to hydroxychloroquine. Interaction of cimetidine with hydroxychloroquine cannot be ruled out. Avoid concomitant use of cimetidine.
Tagamet
Plaquenil
Cimetidine (Tagamet) reduces stomach acid. It is used to treat ulcers, heartburn, and other conditions where too much acid is produced.
Hydroxychloroquine is a drug used to treat or prevent malaria, and to treat certain autoimmune diseases. It works by interfering with the immune system and by killing malaria parasites.
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.
This medicine can treat uncomplicated malaria caused by certain parasites. It can also prevent malaria in areas where the parasites are not resistant to the drug. Hydroxychloroquine also treats rheumatoid arthritis, systemic lupus erythematosus, and chronic discoid lupus erythematosus.
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.
Hydroxychloroquine is an antimalarial and antirheumatic drug. It is thought to work by interfering with the immune system's activity. It also stops the growth of malaria parasites in red blood cells.
- • Headache
- • Dizziness
- • Diarrhea
- • Nausea
- • Vomiting
- • Diarrhea
- • Abdominal pain
- • Fatigue
- Chronic Kidney Disease 1,264
- Acute Kidney Injury 710
- Renal Failure 694
- Nausea 681
- Fatigue 598
- Rheumatoid Arthritis 12,921
- Pain 10,409
- Arthralgia 9,276
- Fatigue 8,853
- Joint Swelling 8,528
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.
This drug can cause heart problems, including a weakened heart muscle and irregular heartbeats. It can also cause irreversible damage to your retina, so regular eye exams are needed. This medicine can also cause serious skin reactions. If you have psoriasis or porphyria, talk to your doctor before taking this medicine. It can also cause liver and kidney problems.
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. This drug can cross the placenta, but studies haven't shown a risk of major birth defects. Talk to your doctor about the risks and benefits of taking this medicine while pregnant. Hydroxychloroquine passes into breast milk. Talk to your doctor about breastfeeding while taking this medicine.
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How to Read This cimetidine vs hydroxychloroquine Comparison
cimetidine is classified in the H2 Receptor Antagonist drug class, while hydroxychloroquine sits within the Disease-Modifying Antirheumatic Drug (DMARD) 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 hydroxychloroquine has 49,987. 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 moderate interaction flagged in FDA labeling, attributed to cimetidine can slow down how your body breaks down hydroxychloroquine, which can double the amount of the drug in your system. this makes side effects much more likely.. 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 hydroxychloroquine.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.