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Aug 11, 2023


7 Important Facts About Phenytoin

1. Phenytoin is an Anti-seizure Medication

Phenytoin (Dilantin) has been approved to treat seizures under three specific conditions. Seizures are episodes of uncontrolled electrical activity in the brain. This can result in a number of different mental and physical changes.

  • Controlling generalized tonic clonic (otherwise known as “grand mal”) seizures
    Tonic clonic seizures are the most well-known of all seizure types. They are characterized by episodes of uncontrolled muscle movement.
  • Controlling complex partial seizures
    Complex partial seizures are those that begin in one side of your brain and may or may not spread to other parts of your brain. They are also associated with impaired consciousness, so the person experiencing the seizure is not fully aware of their surroundings as it occurs.
  • Treating seizures that may occur during or after brain surgery.
    Occasionally seizures can occur during or after brain surgery. Phenytoin is often prescribed in order to treat these isolated seizures.

Read about Types of Seizures

2. Phenytoin Works By Balancing Electrical Activity

Seizures are caused by a disturbance of electrical activity in the brain. Therefore, seizure treatment should be tailored toward preventing this disturbance and/or stopping it once it has started. Most antiepileptic medications work to counteract the seizure activity in the brain.

Phenytoin works to stop the spread of seizure activity and stabilize the brain against uncontrolled electrical activity. It is very effective in controlling seizures. For those who are predisposed to seizures it is often taken for life.

3. Taking Phenytoin Comes With Serious Risks

There are a number of potential very serious risks involved with taking phenytoin. These risks most frequently occur within a short period of time after beginning the medication. The most serious risks encountered include:

  • Suicidal thoughts or self-harming behaviours
    If you experience any thoughts of hurting yourself and/or suicide, seek medical care immediately, as it is a medical emergency.
  • Life-threatening skin conditions
    There are two skin conditions that (rarely) occur following initiation of phenytoin. These skin conditions include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Both conditions present initially with flu-like symptoms and fever and can be fatal if not treated with medical intervention.

Read about Risk of Seizures vs. Risk of Seizure Medications

5. Certain People Shouldn't Take Phenytoin

Although antiepileptics are life-saving medications, there are some people that may require modified therapy due to certain medical conditions. Due to phenytoin’s actions on electrical activity, its use is contraindicated with certain medical conditions. Some of these conditions include:

  • Certain heart conditions
    As both the heart and the brain respond to electrical activity, phenytoin can sometimes have negative effects for those with heart conditions. It is important to talk to your healthcare provider if you have any heart conditions in order to ensure it is safe for you.
  • Absence seizures
    Absence seizures are characterized by unresponsiveness while seemingly staring off into space and are often mistaken for daydreaming.

6. Certain Medications Should Not be Taken at the Same Time as Phenytoin

Due to the way that phenytoin works in your body, there are many substances that cannot be taken at the same time. These substances may increase the activity of phenytoin leading to toxicities or could decrease its activity leading to a lack of effectiveness.

  • Delavirdine
    Administration of both phenytoin and delavirdine can lead to a lack of effect of delavirdine and even possibly resistance.
  • Alcohol
    Alcohol can increase the effects of brain slowing and muscle relaxation.
  • Other anti-epileptic medications (valproic acid, carbamazepine)
    Certain antiepileptics either increase or decrease the effects of phenytoin.
  • Certain antifungals
    Antifungals often increase the effect of phenytoin, while phenytoin can decrease the effects of antifungals.

7. At Marley Drug, You Can Get Your Phenytoin ER Prescription For Less Than $6 Per Month

At Marley Drug, you can get a 6-month supply of phenytoin for $44.71, or a full 12-month supply for only $63.43. This longer supply of medication is ideal for a prescription like phenytoin, as people are required to take this medication for their seizures long-term. This decreased price for longer receiving a greater supply of medication allows you to save money long-term. It also decreases the number of trips you have to take to the pharmacy, which is more convenient, and saves money by decreasing the number of pharmacy dispensing fees you pay.

We are able to price our medications so low because we buy our supplies straight from prescription wholesalers instead of going through insurance companies. Insurance companies are generally responsible for the increase in drug costs. Cutting this step out allows us to offer you much lower prices, often lower than the insurance plans.

Learn more about our pricing model

To learn more about how you can get your phenytoin prescription from Marley Drug, just call us at 1-800-810-7790.

Prices mentioned in this article are based on average retail price at major box chain pharmacy in the U.S. as of November 19, 2022.
  1. Dilantin (phenytoin) – Access data FDA-Approved Drugs [Internet]. [Amended 01/2009; accessed 11/2022].

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