Compare Dilantin vs. Topamax

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Dilantin
(Phenytoin)

Qudexy Xr
(Topiramate)

Prevents seizures. Dilantin (Phenytoin) is effective at preventing seizures, but has many drug interactions and side effects. If your blood tests show that you have the right amount of Dilantin (Phenytoin) levels, you’ll have a lower chance of getting side effects.Prevents seizures and migraine headaches. Qudexy Xr (Topiramate) is useful for preventing seizures and migraines, and doesn't require blood tests while you're on it.
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Reviews & ratings
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Reviews for Qudexy Xr (Topiramate)
54%
29% vs. Dilantin (Phenytoin)
52%
15% vs. Dilantin (Phenytoin)
33%
33% vs. Dilantin (Phenytoin)
Side effects
DilantinTopamax

We haven’t found good data for Dilantin side effects.

FDA side effect reports for Dilantin »
  • Tingling sensation 45%
  • Slowed-down thinking and movements 19%
  • Dizziness 17%
  • Drowsiness 17%
  • Fatigue 17%
  • Change in taste 14%
  • Difficulty with concentration/attention 13%
  • Nervousness 12%
  • Difficulty with memory 11%
  • Vision abnormal 11%
More Topamax side effects »
How it works
DilantinTopamax
Dilantin (Phenytoin) is an antiepileptic medication. It prevents seizures by stabilizing brain cells and lowering abnormal communication within the brain.Qudexy Xr (Topiramate) is an antiepileptic. Researchers don't know exactly how it works, but it seems to affect multiple parts of the brain to control seizures and migraines.
Type of medication
DilantinTopamax
Anticonvulsant
Hydantoin
Prescription only
AnticonvulsantPrescription only
Available as
DilantinTopamax
  • Extended release
  • Chewable tablet
  • Liquid
  • Pill
  • Extended release capsule
Used for (click to learn more)
DilantinTopamax
Risk factors for serious side effects
DilantinTopamax
  • People of Asian ancestry
  • Starting Dilantin (Phenytoin) within the first two months
  • Infusing Dilantin (Phenytoin) too fast
    • History of depression
    • History of osteoporosis
    • History of fractures
    • Stopping Dilantin (Phenytoin) suddenly
    Detailed Dilantin (Phenytoin) risks & warnings »
    • History of depression
      • Children
      • History of metabolic disorders
      • People also taking Depakote
      • Low-carb diet
      • Dehydration
      • Drug interactions
        • Stopping Qudexy Xr (Topiramate) suddenly
        Detailed Qudexy Xr (Topiramate) risks & warnings »
        Pregnancy category
        DilantinTopamax
        DFDA pregnancy category (Weigh risks vs. benefits)

        Research studies with real people found harmful effects on unborn babies, but the benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

        See the FDA package insert
        DFDA pregnancy category (Weigh risks vs. benefits)

        Research studies with real people found harmful effects on unborn babies, but the benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

        See the FDA package insert
        Alcohol
        No specific alcohol-related info.No specific alcohol-related info.
        Food
        No specific food-related info.No specific food-related info.
        Kidneys and liver
        • If you have kidney problems, your dose and kidney function will have to be checked regularly to make sure Dilantin (Phenytoin) levels don’t get too high.
        • A few people will get kidney stones.
        • Qudexy Xr (Topiramate) may increase your risk for kidney stones. Stay well-hydrated to lower your risk.
        Sex
        No specific sex-related info.No specific sex-related info.
        Sleep
        No specific sleep-related info.No specific sleep-related info.
        Weight
        No specific weight-related info.
        • Can cause sleepiness, speech problems, tingling sensations, and weight loss.
        Upsides and benefits
        DilantinTopamax
        • Dilantin (Phenytoin) is effective at preventing seizures, and treating seizures in an emergency.
        • Available in an oral suspension and chewable tablets if you have trouble swallowing capsules.
        • Available as a generic.
        • Used on its own or with other antiepileptic medicines to lower the frequency of seizures, especially for people with tonic-clonic or partial seizures, or Lennox-Gestaut syndrome.
        • Helpful in preventing frequent migraine headaches.
        • Doesn't need routine blood tests.
        Downsides and risks
        DilantinTopamax
        • Need to get blood tests regularly to make sure Dilantin (Phenytoin) has safe and effective levels in your body.
        • Can cause changes in your appearance, such as unwanted hair growth, enlargement of the gums, and coarsening of your facial features.
        • If you have kidney problems, your dose and kidney function will have to be checked regularly to make sure Dilantin (Phenytoin) levels don’t get too high.
        • Can make many other medicines less effective, including birth control.
        • Can cause sleepiness, speech problems, tingling sensations, and weight loss.
        • A few people will get kidney stones.
        • Not safe to use if you're pregnant.
        Tips from our pharmacists for people taking the medication
        DilantinTopamax
        • Can cause loss of coordination, confusion, uncontrollable eye movements, and unwanted hair growth while on this.
        • If you’re taking supplements, let your doctor know. You’ll likely have to space out the supplements and Dilantin (Phenytoin) so they don’t interact.
        • If you start having skin rashes or thoughts of suicide, tell your doctor immediately.
        • Makes many drugs less effective, so make sure your doctor has a complete list of what you’re taking.
        • If you need to stop taking Dilantin (Phenytoin), do so over at least one week to prevent withdrawal seizures.
        • For the first week, avoid activities that require you to be alert.
        • Don't use if pregnant.
        • Can cause tingling skin sensations and reduced appetite.
        • Report any confusion, decreased sweating, fever, or changes in behavior or vision.
        • Takes 3 to 4 weeks to feel full effects on mood.
        Learn more
        More about DilantinSide effectsReviews & ratingsAlternativesFDA package insert
        More about TopamaxSide effectsReviews & ratingsAlternativesFDA package insert