Two medicines, side by side
Phenytoin vs ranolazine
Phenytoin is labeled for seizures and epilepsy; ranolazine for angina. Their labels share no use, so they are not alternatives to each other. Drugs@FDA records approvals of phenytoin since 1953 and of ranolazine since 2006. Pharmacies paid $0.145 per phenytoin sod ext 100 mg capsule and $0.165 per ranolazine ER 500 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. In FDA's classes, phenytoin is an anti-epileptic agent and ranolazine an anti-anginal.
Check it at the source: the phenytoin FDA label on DailyMed (effective October 15, 2024); the ranolazine FDA label on DailyMed (effective January 23, 2026).
Highlights of the phenytoin record
Phenytoin (Dilantin) · label of October 15, 2024
Used for
From the label: indicationsPHENYTEK ® capsules (extended phenytoin sodium capsules) are indicated for the treatment of tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures and prevention and treatment of seizures occurring during or following neurosurgery. […]
On the market
- Earliest approval on file
- January 6, 1953
- Generic labelers
- 29 labelers
- Pharmacy cost
- $0.145 per capsule
Supply and safety
- Shortage
- No current entry
- Recalls
- 11
Highlights of the ranolazine record
Ranolazine (Ranexa) · label of January 23, 2026
Used for
From the label: indicationsRanolazine extended-release tablets are indicated for the treatment of chronic angina. Ranolazine extended-release tablets may be used with beta-blockers, nitrates, calcium channel blockers, anti-platelet therapy, lipid-lowering therapy, ACE inhibitors, and angiotensin receptor blockers. Ranolazine extended-release tablets are an antianginal indicated for the treatment of chronic angina.
On the market
- Earliest approval on file
- January 27, 2006
- Generic labelers
- 28 labelers
- Pharmacy cost
- $0.165 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 2
Source: FDA drug labels via openFDA (Phenytoin label of October 15, 2024, Ranolazine label of January 23, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do phenytoin and ranolazine differ on the record?
In FDA's classes, phenytoin is an anti-epileptic agent and ranolazine an anti-anginal.
How each works, in its label's words: Phenytoin, “The precise mechanism by which phenytoin exerts its therapeutic effect has not been established but is thought to involve the voltage-dependent blockade of membrane sodium channels resulting in a …”; Ranolazine, “The mechanism of action of ranolazine’s antianginal effects has not been determined.”
Half-life, in each label's words: Phenytoin, “Elimination The plasma half-life in man after oral administration of phenytoin averages 22 hours, with a range of 7 to …”; Ranolazine, “The apparent terminal half-life of ranolazine is 7 hours.”
Generics: phenytoin since 1975; ranolazine since 2013 (Drugs@FDA).
| Phenytoin | Ranolazine | |
|---|---|---|
| Labeled for | Seizures and epilepsy | Angina |
| Pharmacologic class | Anti-epileptic Agent | Anti-anginal |
| How it works (label) | The precise mechanism by which phenytoin exerts its therapeutic effect has not been established but is thought to involve the voltage-dependent blockade of membrane sodium channels resulting in a reduction in sustained high-frequency … | The mechanism of action of ranolazine’s antianginal effects has not been determined. Ranolazine has anti-ischemic and antianginal effects that do not depend upon reductions in heart rate or blood pressure. |
| Half-life (label) | Elimination The plasma half-life in man after oral administration of phenytoin averages 22 hours, with a range of 7 to 42 hours. | The apparent terminal half-life of ranolazine is 7 hours. |
| Earliest approval on file (Drugs@FDA) | January 6, 1953 | January 27, 2006 |
| First generic approved | July 16, 1975 | July 29, 2013 |
| Generic labelers (NDC) | 29 labelers | 28 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.145 per capsule (Phenytoin sod ext 100 mg capsule) | $0.165 per tablet (Ranolazine ER 500 mg tablet) |
| 12-month price change | -5% | -2% |
| Boxed warning | No | No |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 11 | 2 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 40,278 | 10,376 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
Do their labels mention each other?
Ranolazine label, drug interactionsCYP3A Inducers Do not use ranolazine with CYP3A inducers such as rifampin, rifabutin, rifapentine, phenobarbital, phenytoin, carbamazepine, and St. John’s wort [see Contraindications (4), Clinical Pharmacology (12.3) ].
Ranolazine label, drug interactionsCYP3A Inducers Concomitant use of ASPRUZYO Sprinkle with CYP3A inducers such as rifampin, rifabutin, rifapentine, phenobarbital, phenytoin, carbamazepine, and St. John's wort is contraindicated [see Contraindications (4), Clinical Pharmacology (12.3)].
Source: FDA drug labels via openFDA
What next?
- Alternatives to phenytoin
- every medicine labeled for the same conditions