Dilantin® (phenytoin) for seizure control and maintenance therapy

What Dilantin® Is and How It Works

Dilantin is the phenytoin brand name used to manage certain seizure types. It helps control focal onset seizures and generalized tonic-clonic seizures. It is not effective for absence seizures. The medicine stabilizes neuronal firing by blocking voltage-gated sodium channels.

YouDrugstore is a licensed Canadian pharmacy headquartered in Manitoba, and prescriptions are reviewed by licensed pharmacists before dispensing.

Phenytoin, the generic for Dilantin, comes as extended-release 100 mg capsules (often called Dilantin Kapseal), chewable tablets, and an oral suspension. Some people search for Dilantin tablets, but the standard brand form is an extended-release capsule. Typical maintenance is near “dilantin 300 mg” daily, taken in divided doses, but dosing is individualized.

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Dilantin’s non-linear pharmacokinetics require careful titration. Small dose changes can produce large shifts in blood levels. Your prescriber may request phenytoin levels to stay near the usual therapeutic range of 10–20 mcg/mL. Consistent dosing time and consistent food intake help keep levels steady.

Dosage and Usage

• Start doses are often 100 mg three times daily or as directed; some regimens use 300 mg once daily of extended-release capsules for maintenance.
• Swallow extended-release Dilantin Kapseal capsules whole. Do not crush, break, or chew.
• If prescribed chewables (Infatabs) or a liquid, follow the labeled amount carefully. Shake the suspension well before each dose.
• Take doses at the same times every day. Keep your routine consistent with meals.
• If you miss a dose, take it when remembered unless it is close to the next dose. Do not double up.
• Do not stop Dilantin suddenly. Stopping abruptly can increase seizure risk.
• Separate from antacids and calcium supplements by at least 2 hours. Enteral tube feeds can reduce absorption; your prescriber may adjust timing.
• Tell your care team about all medicines you take. Phenytoin has many drug interactions, including with warfarin and hormonal contraceptives.

• Store capsules and tablets at 20–25°C (68–77°F). Brief excursions 15–30°C (59–86°F) are acceptable.
• Keep away from moisture and heat. Leave in the original bottle with the desiccant.
• For suspension, keep the cap tightly closed. Do not freeze. Shake well before use.
• For travel, keep your Dilantin in carry-on luggage. Avoid temperatures above 30°C (86°F).
• Bring enough supply for your trip and a copy of your prescription. Use a pill organizer only if it stays dry and cool.
• Do not use if the suspension separates after shaking or the capsules are damaged.

Benefits and Savings

Dilantin medicine has decades of use for controlling tonic-clonic and focal seizures. Extended-release dosing can simplify schedules and improve adherence. Many patients stabilize on a once-daily regimen after titration. Your prescriber chooses the form that fits your needs, including chewable or liquid options.

Ordering from Canada often reduces dilantin cost. Typical savings versus US prices range from 60–80%. Compare dilantin price across strengths, and you can lower monthly costs with multi-month supplies. We also send reorder reminders so you can avoid running out.

Brand name for Dilantin is phenytoin’s trade name, and you can also choose approved generics. Some customers compare dilantin 100 mg price or dilantin 100mg cost with brand and generic options to find the best fit. We list clear pricing for Dilantin Pfizer products where available and their generic equivalents.

See current offers on our promotions page if you are looking for a dilantin coupon.

Side Effects and Safety

• Dizziness, drowsiness, headache
• Nausea, vomiting, constipation
• Gingival (gum) overgrowth, especially with poor dental hygiene
• Ataxia (unsteady gait), tremor, slurred speech
• Blurred or double vision; nystagmus
• Rash or itching
• Hair growth changes and skin coarsening with long-term use
• Low folate levels; low vitamin D and bone thinning over time

Serious risks are uncommon but can include severe skin reactions such as Stevens–Johnson syndrome/toxic epidermal necrolysis, DRESS (drug reaction with eosinophilia and systemic symptoms), liver injury, blood disorders, mood changes or suicidal thoughts, and lupus-like reactions. Risk of severe rash is higher in some Asian populations with HLA-B*1502. Alcohol can raise or lower phenytoin levels and should be discussed with your prescriber.

Onset Time

Some seizure control may appear once therapeutic levels are reached, often within a few days of dose titration. Because phenytoin reaches steady state over about 7–10 days, your prescriber may wait a week or more between dose changes and level checks. Clinical response depends on seizure type, dose, and adherence.

Compare With Alternatives

Lamotrigine is a common alternative for focal and generalized tonic-clonic seizures, with fewer cosmetic side effects but a slower titration to reduce rash risk. You can compare with Lamictal® when deciding on a long-term option with your prescriber.

Levetiracetam is another widely used option for focal seizures. It is renally cleared and has fewer drug interactions, though mood changes can occur. Carbamazepine is effective for focal seizures but has enzyme-inducing effects and notable interactions.

If you need a liquid form or chewable, phenytoin offers alternatives within the same molecule. Consider the oral liquid via Dilantin® Suspension or chewables when swallowing capsules is difficult.

Combination Therapy

• Phenytoin with levetiracetam: common add-on with minimal metabolic interaction.
• Phenytoin with lamotrigine: titrate lamotrigine faster if on enzyme inducers; monitor for rash.
• Phenytoin with valproate: valproate can increase free phenytoin; monitor levels and effects.
• Phenytoin with topiramate or lacosamide: additive benefit in refractory focal seizures; watch for CNS effects.
• Oral contraceptives can be less effective with phenytoin. Discuss non-hormonal options.

Patient Suitability and Cost-Saving Tips

Dilantin 100 mg uses include maintenance treatment of focal and generalized tonic-clonic seizures. It is not a first-line choice for absence seizures. People with prior hypersensitivity to phenytoin, or to other hydantoins, should avoid it. Severe liver disease, porphyria, and a history of serious rash with antiepileptics require careful evaluation.

Pregnancy requires individualized counseling. Phenytoin can cause fetal harm, and folate and vitamin D support may be considered. If you are of Asian ancestry, HLA-B*1502 testing may be discussed due to rash risk. Regular dental care helps reduce gingival overgrowth. Bone health planning is often needed with long-term therapy.

Talk to your clinician about drug interactions before starting or stopping any medicine. Phenytoin is a strong enzyme inducer and can change levels of warfarin, certain antivirals, antifungals, and many other drugs.

For budgeting, compare dilantin price by strength and brand vs generic. A three-month fill can lower per-month costs, and bulk promotions sometimes apply. Set up simple reorder reminders in your account so you maintain supply. If you need chewables, you might review Dilantin® Infatabs alongside your capsule regimen.

Authoritative Sources

Pfizer Canada product information

Health Canada Drug Product Database

FDA Prescribing Information: Phenytoin Sodium Extended-Release

Order Dilantin® from YouDrugstore: add to cart, upload your prescription, and we ship with prompt, express, cold-chain handling.

This page is educational and does not replace advice from your healthcare professional.