carbidopa/levodopa vs phenytoin
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Side-by-side comparison of carbidopa/levodopa 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
7 DRUG INTERACTIONS Drugs metabolized by COMT: use with caution ( 5.10 , 7.2 ) Anti-hypertensive agents: dose adjustment may be required ( 7.3 ) Tricyclic antidepressants: risk of hypertension and dyskinesia reported during concomitant use with carbidopa/levodopa ( 7.4 ) Dopamine D2 receptor antagonists, isoniazid, phenytoin, papaverine and iron salts: may reduce efficacy of carbidopa, levodopa and entacapone tablets ( 7.5 , 7.6 , 7.7 , 7.8 , 7.9 ) Drugs that interfere with biliary excretion, glucuronidation and intestinal beta-glucuronidase: dose adjustment of carbidopa, levodopa and...
Sinemet
Dilantin
This medicine contains carbidopa, levodopa, and entacapone. It is used to treat Parkinson's disease.
Phenytoin injection is used to treat certain types of seizures. It can also prevent seizures during or after neurosurgery.
This medicine treats Parkinson's disease. It can help when other medicines stop working as well near the end of a dose. It can also replace other medicines containing similar ingredients.
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.
Levodopa turns into dopamine in your brain, helping to control movement. Carbidopa helps levodopa get to your brain. Entacapone helps levodopa work longer.
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.
- • Uncontrolled movements
- • Diarrhea
- • Nausea
- • Belly pain
- • Vomiting
No common side effects listed.
- Fall 4,293
- Seeing or hearing things that are not there 3,733
- Shaking 3,257
- Uncontrolled movements 2,903
- Death 2,727
- Drug Interaction 1,547
- Seizure 1,382
- Toxicity To Various Agents 1,353
- Convulsion 1,262
- Status Epilepticus 791
This medicine can make you fall asleep suddenly, even when you feel awake. Be careful when driving or doing other activities where you need to be alert. Stopping this medicine suddenly can cause serious problems like fever and confusion.
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.
This medicine may harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if this medicine passes into breast milk.
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.
How to Read This carbidopa/levodopa vs phenytoin Comparison
carbidopa/levodopa is classified in the Dopamine Precursor Combination 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, carbidopa/levodopa has 16,913 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 phenytoin can interfere with how carbidopa and levodopa work in the body. this makes the parkinson's medication less effective at controlling symptoms.. 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 carbidopa/levodopa or phenytoin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.