clonazepam vs phenytoin
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Side-by-side comparison of clonazepam and phenytoin. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
Clonazepam has the potential to influence concentrations of phenytoin. Monitoring of phenytoin concentration is recommended when clonazepam is co-administrated with phenytoin. Cytochrome P450 inducers, such as phenytoin, carbamazepine, lamotrigine, and phenobarbital induce clonazepam metabolism, causing an approximately 38% decrease in plasma clonazepam levels.
Klonopin
Dilantin
Clonazepam is a medicine that belongs to the benzodiazepine class. It is used to treat seizure disorders and panic disorder.
Phenytoin injection is used to treat certain types of seizures. It can also prevent seizures during or after neurosurgery.
Clonazepam is used to treat certain seizure disorders, including Lennox-Gastaut syndrome, akinetic, and myoclonic seizures. It can also treat absence seizures when other medicines don't work. Clonazepam also treats panic disorder, which involves unexpected panic attacks and worry about having more attacks.
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.
Clonazepam works by affecting chemicals in your brain that may be unbalanced. It enhances the effects of a natural brain chemical called GABA. This helps to reduce seizures and relieve panic symptoms.
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.
- • Drowsiness
- • Problems with coordination
No common side effects listed.
- Fatigue 10,236
- Nausea 9,564
- Anxiety 8,735
- Headache 8,590
- Depression 8,121
- Drug Interaction 1,547
- Seizure 1,382
- Toxicity To Various Agents 1,353
- Convulsion 1,262
- Status Epilepticus 791
Taking clonazepam with opioid medicines can cause very serious problems, including slowed breathing, coma, and death. Only take these medicines together if there are no other options. Clonazepam can be habit-forming, leading to abuse, misuse, and addiction, which can result in overdose or death. Stopping clonazepam suddenly can cause dangerous withdrawal symptoms. Your doctor will slowly lower your dose to prevent withdrawal.
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.
Clonazepam may harm an unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. Clonazepam can pass into breast milk and may harm a nursing infant.
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 clonazepam vs phenytoin Comparison
clonazepam is classified in the Benzodiazepine 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, clonazepam has 45,246 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 minor interaction flagged in FDA labeling, attributed to phenytoin makes your body clear clonazepam faster, and clonazepam can also change the amount of phenytoin in your system.. 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 clonazepam or phenytoin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.