All About Dilantin

What are Dilantin’s side effects?

Like most drugs, Dilantin may cause mild to serious side effects. The lists below contain some of the more common side effects Dilantin may cause, but they don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

• your age
• other health conditions you have
• other medications you take
• the dosage and form of the drug you’re prescribed

Your doctor or pharmacist can tell you more about the potential side effects of Dilantin. They can also suggest ways to help reduce or manage any side effects you might have.

Mild side effects

Below is a list of some of the mild side effects Dilantin can cause. To learn about other mild side effects, talk with your doctor or pharmacist. Or you can read Dilantin’s prescribing information for the specific form you’re prescribed (Dilantin-125 oral liquid suspension, Dilantin Infatabs chewable tablets, or Dilantin extended-release capsules).

Mild side effects of Dilantin that have been reported include:

• uncontrollable eye movements
• slurred speech
• clumsiness or other problems with coordination
• sleepiness, tiredness, or confusion

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Dilantin can occur, but they aren’t common. If you have serious side effects from this medication, call your doctor right away. But if you think you’re having a medical emergency, call 911 or your local emergency number.

Serious side effects of Dilantin that have been reported include:

• changes in mental health, including new or worsening depression or suicidal behavior
• heart problems, including a slower heart rate than normal or cardiac arrest
• liver problems
• gingival hyperplasia
• lower levels of platelets and white blood cells
• higher blood sugar than usual
• bone problems, including osteoporosis and a low level of vitamin D in the blood
• serious skin problems, including Stevens-Johnson syndrome and toxic epidermal necrolysis

Allergic reaction

For some people, Dilantin can cause an allergic reaction, including drug rash with eosinophilia and systemic symptoms (DRESS). To learn more about this risk, talk with your doctor. Or check out the prescribing information for the specific form they prescribe for you (Dilantin-125 oral liquid suspension, Dilantin Infatabs chewable tablets, or Dilantin extended-release capsules).

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Dilantin.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Dilantin, they may have you switch to a different treatment.

What is Dilantin’s dosage?

Below are commonly used dosages of Dilantin, but always take the dosage your doctor prescribes. They’ll recommend the dosage that’s right for you.

Forms and strengths

Dilantin is available in three oral forms. The suspension (Dilantin-125) and chewable tablets (Dilantin Infatabs) are immediate-release, meaning the drug is released into your body right away.

• Dilantin-125 is available in one strength of 125 milligrams (mg) in 5 milliliters (mL) of oral suspension.
• Dilantin Infatabs chewable tablets are available in one strength of 50 mg.

Dilantin is also available in extended-release capsules, which cause the drug to be released slowly into your body over time. These capsules are available in two strengths: 30 mg and 100 mg.

Recommended dosages

Your Dilantin dosage will depend on the form of the drug you’re prescribed and how your body responds to that dose and form. It may also depend on what seizure medications you’ve taken in the past.

Your doctor may gradually increase your dosage based on blood tests and how well Dilantin manages your seizures. If your dosage needs to be changed, they’ll wait at least 7 to 10 days between adjustments.

Dilantin-125 dosage

For adults:

• You’ll likely be prescribed a starting dosage of 5 mL three times per day.
• The maximum dosage is 25 mL per day.

For children:

• They’ll likely be prescribed a starting dosage of 5 mg per kilogram (kg) of body weight per day divided into two or three doses. (For reference, 1 kg equals about 2.2 pounds.)
• The maximum dosage is 300 mg per day (12 mL).

Dilantin Infatabs dosage

For adults:

• You’ll likely be prescribed a starting dosage of two tablets (totaling 100 mg) three times per day.
• Most adults need 6 to 8 tablets per day to treat their seizures (totaling 300 to 400 mg per day).
• The maximum dose is 12 tablets per day (600 mg per day).

For children:

• They’ll likely be prescribed a starting dose of 5 mg/kg/day divided into two or three doses.
  (For reference, 1 kg equals about 2.2 pounds.)
• The maximum dosage is 6 tablets per day (300 mg per day).

Dilantin extended-release capsules dosage

For adults:

• You’ll likely be prescribed a starting dosage of a 100-mg capsule three times per day.
• Most adults need one 100-mg capsule three to four times per day to treat their seizures.
• If you see a doctor in a clinic or hospital for your seizures, you may be given a loading dose. This helps the drug take effect faster if your seizures need more rapid treatment. But you likely won’t receive a loading dose if you have kidney or liver problems.
• If your seizures are treated with 100 mg three times daily, your doctor may allow you to start taking 300 mg once per day instead. This can make it easier to remember to take the drug. The extended-release capsules are the only oral form of Dilantin that can be taken once daily.
• The maximum dosage of Dilantin is two capsules three times per day (600 mg per day).

For children:

• They’ll likely be prescribed a starting dose of 5 mg/kg/day divided into two or three doses.
  (For reference, 1 kg equals about 2.2 pounds.)
• The maximum dosage is one capsule three times per day (300 mg per day).

Questions about taking Dilantin

Below are some common questions about taking Dilantin.

• Can Dilantin be chewed, crushed, or split? Dilantin Infatabs can be cut in half, chewed, or swallowed whole. But you should swallow Dilantin extended-release capsules whole. If you have trouble swallowing pills, check out this article or ask your doctor or pharmacist for advice. Dilantin-125 is available as a liquid suspension that may be easier for you to take. Ask your doctor about which form of Dilantin is best for you.
• Should I take Dilantin with food? Studies for Dilantin-125, Dilantin Infatabs, and Dilantin extended-release capsules don’t specify whether to take the drug with or without food.
• Is there a best time of day to take Dilantin? Dilantin can be taken at any time of day, but it’s best to take each prescribed dose around the same time each day. This helps keep a consistent level of the drug in your body, which helps it work effectively.
• What if I miss a dose of Dilantin? If you miss a dose of Dilantin, take it as soon as you remember. But if it’s almost time to take your next dose, skip the missed dose and take the next dose at its usual time. You should not take two doses at once to make up for a missed dose. Doing so could increase your risk of side effects.
• Will I need to take Dilantin long term? Dilantin is typically a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely take it long term.
• How long does Dilantin take to work? Your doctor will order blood tests to measure the level of the drug in your body. They may then adjust your dosage every 7 to 10 days until your levels are adequate to treat your condition. How long Dilantin takes to treat your seizures largely depends on how your body responds to the drug.

Overdose

Do not take more Dilantin than your doctor prescribes, as this can lead to harmful effects.

Effects of overdose

Symptoms caused by an overdose (also called toxicity symptoms) can include:

• problems with coordination
• slurred speech or difficulty speaking
• blurred vision
• tiredness
• nausea and vomiting
• tremor
• twitching
• low blood pressure or heart rate
• cardiac arrest
• coma

In rare cases, overdose of Dilantin may cause death.

What to do in case you take too much Dilantin

Call your doctor if you think you’ve taken too much Dilantin. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. If you have severe symptoms, immediately call 911 or your local emergency number or go to the nearest emergency room.

What is Dilantin used for?

Dilantin is prescribed to treat tonic-clonic (grand mal) seizure and psychomotor (temporal lobe) seizure in adults and certain children. Certain forms of this drug (Dilantin Infatabs chewable tablets and Dilantin-125 oral liquid suspension) may also be used to help prevent or treat seizure during or after brain surgery.

Seizures start in certain areas of your brain from unexpected electrical signals. While symptoms between seizure types may vary slightly, you may experience convulsions and loss of consciousness.

It’s not fully known how Dilantin works for seizure treatment. However, it’s thought that the drug reduces the electrical signals your brain sends to your body. This may help reduce seizure symptoms and their frequency.

What are some frequently asked questions about Dilantin?

Find answers to some commonly asked questions about Dilantin.

Is Dilantin a controlled substance?

No, Dilantin is not a controlled substance.

Is there a risk of withdrawal with Dilantin?

If you suddenly stop taking Dilantin, you may experience withdrawal seizures. This means that you may have seizures, even if you haven’t had them while taking Dilantin. These seizures may be life threatening, a condition known as status epilepticus.

Because of this risk, any dosage changes, including stopping Dilantin, should be done gradually under your doctor’s direction.

What should be considered before taking Dilantin?

Below is important information you should consider before starting Dilantin.

Interactions

Taking a drug with certain medications, vaccines, foods, and other things can affect how the drug works. These effects are called interactions. Dilantin can interact with several other medications. It can also interact with certain supplements as well as certain foods.

Before taking Dilantin, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

Drug interactions

Below is a list of medications that can interact with Dilantin. This list does not contain all drugs that may interact with Dilantin. For more information on Dilantin and interactions, check out this article. If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Dilantin and alcohol

It’s not safe to consume alcohol while taking Dilantin. Alcohol could change the level of Dilantin in your body, which could increase your risk of seizure or side effects.

Other interactions

Dilantin can interact with other substances, such as:

• Vitamins or supplements: Dilantin interacts with vitamin D and folic acid supplements. Dilantin also interacts with St. John’s wort. Your doctor will likely recommend that you avoid taking these vitamins and supplements during your Dilantin treatment.
• Foods: Receiving your nutrition through a feeding tube may lower your Dilantin blood levels and possibly reduce the effectiveness if given at the same time. Your doctor will likely recommend that you separate your Dilantin doses from your tube feeding. They may also check your Dilantin blood levels more often if you’re receiving tube feedings.

Pregnancy and breastfeeding

Taking Dilantin during pregnancy may contribute to problems with fetal development (commonly known as birth defects). But leaving seizures untreated while pregnant has risks, too.

If you take Dilantin while you’re pregnant, consider enrolling in The North American Antiepileptic Drug Pregnancy Registry. This registry collects information about the effects of antiepileptic (antiseizure) drugs on different aspects of pregnancy. Call 888-233-2334 or visit the registry’s website to learn more.

It’s not known whether it’s safe to take Dilantin while breastfeeding. Dilantin passes into breastmilk, but its effects on children who are breastfed haven’t been studied.

If you’re pregnant or breastfeeding, or planning to be either, talk with your doctor about the risks and benefits of Dilantin before starting treatment.

Birth control

If you’re able to become pregnant, you should use birth control throughout your Dilantin treatment. You may need to change your method if you’re taking birth control pills or using a vaginal ring that contain estrogen. Dilantin can interact with estrogen-containing contraceptives. Talk with your doctor to learn more about effective birth control methods you can use while taking Dilantin.

Warnings

Dilantin can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Dilantin is a good treatment option for you.

Talk with your doctor about your health history before starting Dilantin. Be sure to tell them if any of the following factors apply to you:

• mental health conditions, including new or worsening depression or a history of suicidal thoughts or behavior
• liver problems, especially if you’ve taken Dilantin in the past and had problems
• kidney problems
• porphyria (rare, inherited blood disorders)
• if you’re also taking delavirdine, a medication used to treat HIV
• diabetes
• bone problems, including osteoporosis and a low level of vitamin D
• heart problems, including having a slow heart rate or cardiac arrest in the past
• low levels of platelets, white blood cells, or albumin
• if you’ve had serious skin problems, including Stevens-Johnson syndrome and toxic epidermal necrolysis, and have certain genetic factors as determined by your doctor
• previous allergic reaction to Dilantin or another drug in its group
• pregnancy
• breastfeeding

Dilantin cost and coupons

Whether you have health insurance or not, cost may be a factor when you’re considering Dilantin. What you’ll pay for Dilantin may depend on several things, such as your treatment plan and the pharmacy you use.

Here are a few things to consider regarding cost:

• Cost information and savings coupons: You can visit Optum Perks to get price estimates of what you’d pay for Dilantin when using coupons from the site. See the coupon options below. (Note: Optum Perks coupons cannot be used with any insurance copays or benefits.)
• Generic form: Dilantin is available as the generic drug phenytoin. Generics usually cost less than brand-name drugs. Talk with your doctor if you’d like to know whether generic phenytoin could be an option for you.
• Savings program: If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. You may be eligible for a Dilantin Savings Card.

You can also check out this article to learn more about saving money on prescriptions.

Save on your Dilantin prescription

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Retail price refers to the manufacturer’s published list price and is up to date as of 3/2023. Retail and discounted prices are U.S.-only and can vary based on region and pharmacy. We cannot guarantee that the discounted price listed here will exactly match the price at your pharmacy. Please contact your pharmacy for the exact price.

Optum Perks and Healthline are subsidiaries of RVO Health.

Pricing source:Perks.optum.com

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