clarithromycin vs phenytoin
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Side-by-side comparison of clarithromycin and phenytoin. 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
Other Drugs Metabolized by CYP450 Isoforms Other than CYP3A: Hexobarbital Phenytoin Valproate Use With Caution There have been postmarketing reports of interactions of clarithromycin with drugs not thought to be metabolized by CYP3A, including hexobarbital, phenytoin, and valproate.
Biaxin
Dilantin
Clarithromycin is an antibiotic that fights bacterial infections. It belongs to a class of drugs called macrolides.
Phenytoin injection is used to treat certain types of seizures. It can also prevent seizures during or after neurosurgery.
Clarithromycin treats mild to moderate infections caused by certain bacteria. It can treat bronchitis, sinus infections, pneumonia, and throat/tonsil infections. It also treats skin infections, ear infections in children, certain mycobacterial infections, and H. pylori infections that cause ulcers.
This medicine treats generalized tonic-clonic status epilepticus, a type of prolonged seizure. It also helps prevent and treat seizures that may happen during or after brain surgery. Sometimes, it can be used for a short time instead of the oral form of phenytoin when you cannot take the medicine by mouth.
Clarithromycin works by stopping the growth of bacteria. It prevents bacteria from making proteins they need to survive. This helps your body fight off the infection.
Phenytoin works by slowing down the signals in the brain that cause seizures. It stabilizes nerve cell membranes, reducing excessive electrical activity. This helps to prevent seizures from starting or spreading.
- • Abdominal pain
- • Diarrhea
- • Nausea
- • Vomiting
- • Taste changes
No common side effects listed.
- Drug Interaction 2,906
- Nausea 2,214
- Dyspnoea 1,959
- Diarrhoea 1,937
- Malaise 1,650
- Drug Interaction 1,547
- Seizure 1,382
- Toxicity To Various Agents 1,353
- Convulsion 1,262
- Status Epilepticus 791
Clarithromycin can cause severe allergic reactions. Stop taking it and get medical help right away if you have signs of a reaction. This medicine can also cause heart rhythm problems (QT prolongation) and liver problems. Tell your doctor if you have heart or liver issues. Clarithromycin may increase the risk of death in patients with coronary artery disease.
This medicine can cause serious heart problems if given too quickly. The injection rate should not be faster than 50 mg per minute for adults, and 1 to 3 mg/kg/min (or 50 mg per minute, whichever is slower) for children. Your heart will be monitored closely during and after the injection.
Clarithromycin is not recommended during pregnancy unless there are no other options. Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if clarithromycin passes into breast milk, so talk to your doctor before breastfeeding.
Taking phenytoin during pregnancy may increase the risk of birth defects. If you are pregnant or plan to become pregnant, talk to your doctor about the risks and benefits of this medicine.
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How to Read This clarithromycin vs phenytoin Comparison
clarithromycin is classified in the Macrolide Antibiotic drug class, while phenytoin sits within the Anticonvulsant (Hydantoin) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, clarithromycin has 10,666 submissions while phenytoin has 6,335. 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 clarithromycin can interfere with how your body processes phenytoin, which may lead to higher levels of the drug.. 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 clarithromycin or phenytoin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.