Primidone (Oral)

By controlling the electrical impulses in the brain, Primidone works to treat seizures and seizure-inducing conditions.


As a barbiturate, Primidone can be a valuable treatment for seizures. This drug may improve the lives of those suffering from them, and prevent life-threatening seizures from occurring. However, it should be taken cautiously to prevent addiction, complications, or overdose.

This drug is only available if it is prescribed by your doctor. They may prescribe a name-brand (Mysoline) or generic form of the drug. It is only available orally, so do not take it in any other way. This drug may require a specific dosing schedule, and your dose may change depending on how much you need. Follow your doctor's instructions carefully, and do not change their dose unless they advise it.

Primidone may become addictive, especially if you take large doses for a long period of time. If you or your family has a history of addiction or addictive tendencies, take caution while using this drug. Make sure to inform your doctor of this. They may lower your dose to make sure that you remain safe while taking this drug.

Do not stop using Primidone abruptly. This may endanger your health and cause additional, extreme seizures. If you need to stop using this drug, talk to your doctor about the step-down process. Keep in mind that your seizures should not go untreated. Herbal and spiritual methods are not reliable sources of treatment, and medication may be the only thing preventing life-threatening seizures.

Use this drug responsibly, and never take more than directed. Overdose and addiction are real dangers, and you should take them seriously while using this drug. If you have concerns, questions, or want further insight on how this drug might affect you, talk to your doctor.

Conditions Treated

  • Seizures

Type Of Medication

  • Barbiturate

Side Effects

This drug may cause side effects, especially if you have just begun taking it. Side effects may disappear or lessen over time, so do not judge this treatment by the first few weeks of your prescription. While you should monitor your body for harmful side effects, do not overreact and try to stay positive about your medication. Contact your doctor if your side effects worsen, become severe, or persist.

Some side effects are mild and do not require medical attention. These side effects may be troublesome or uncomfortable, but they should not stop you from taking your daily medication. If they persist into your daily life, talk to your doctor. They may lower your dose of Primidone, or prescribe an additional medication to manage these side effects.

Mild side effects include:

  • Nausea
  • Vomiting
  • Drowsiness
  • Dizziness
  • Tiredness
  • Loss of appetite
  • Headache
  • Excitability

These side effects are normal and do not require any medical attention or concern. If they become severe, contact your doctor. Do not stop taking this drug just because you dislike the side effects. Give your treatment time, and speak to your doctor about possible solutions. Going unmedicated may be dangerous, so you should use your medications with an open mind.

Some side effects may be a symptom of a larger problem. Talk to your doctor if you experience:

  • Staggering
  • Unsteadiness
  • Trembling
  • Loss of coordination
  • Restlessness
  • Signs of infection or flu-like symptoms
  • Weakness
  • Pale skin
  • Shortened breath
  • Unusual bleeding and bruising

While rare, these side effects may be a sign that Primidone is negatively affecting your body. If these symptoms occur, speak to your doctor immediately and begin stepping down off this drug. If you believe your life is in danger at any point, contact medical help right away.

You may experience allergies if you have a sensitivity to anticonvulsants or barbiturates of this kind. Do not take this drug if you have an allergy to it, and do not continue taking this drug if you experience allergy symptoms. Signs of an allergic reaction include:

  • Skin rash
  • Blistering
  • Unexplained fever
  • Stomach upset
  • Swelling of the mouth/face/tongue
  • Itching of the mouth/face/tongue
  • Closing of the throat/airways
  • Trouble breathing

If you experience allergy symptoms, stop taking this drug immediately. You should begin experiencing them within your first few doses, so monitor yourself during your first week of treatment. If they become severe or life-threatening, contact medical help. If you have a known allergy to this drug or its active/inactive ingredients, make sure to tell your doctor before your first dose.


Dosing for this drug may vary from patient to patient. Do not judge your dose based on any outside information, including online sites or others' experiences. Only take the dose your doctor prescribes, as it is tailored to fit you and your condition. Your dose may change according to your age, your condition, your reaction to the first dose, and other factors.

This drug can cause addiction and overdose if taken recklessly, so use caution when using this medication. Contact your doctor if you have questions or wish to change your dose, and only do so with their approval.

Primidone is an oral medication, so it should only be taken orally. Do not take this drug any other way. It is available in pills/tablets and oral suspensions. Make sure to store this drug responsibly, and try to take your dose every day at the same time. Make alarms or schedules to make sure you receive your dose on time.

If you miss a dose, take it as soon as you remember, or just skip it and resume your normal dosing schedule. Do not double-dose. Avoid missing doses, as it can upset your schedule and cause issues.

Children can take this drug, but they should do so with parental supervision. Never allow a child to handle medication, and parental guardians or caretakers should always administer it themselves.

Recommended doses are as follows:

For adults and children over the age of 8: 100-125mg daily. Your doctor may increase or lower your dose as necessary.

For children under the age of 8: 50mg daily as a starting dose. The doctor may advise increasing or decreasing the dose according to their reaction.

This drug should be taken at night before bedtime. To avoid stomach upset, your doctor may recommend that this drug be taken with food or drink, particularly milk. Children taking this drug may prefer chewable tablets, which should be available. Only use this drug as directed, and always monitor children and teenagers over the course of their treatment.


Primidone may cause interactions with other drugs in your prescription list. These interactions can vary between mild and severe and should be avoided if possible. Make sure to keep a detailed list of all your medications, both OTC and prescription. This includes herbal supplements. Inform your doctor if you are taking any interactive medications.

Your doctor may change your dose of Primidone, change the dose of your other medications, or switch you to entirely new medications. While unpleasant, this may be necessary to avoid serious interactions and side effects. Always follow your doctor's orders when using this medication in tandem with other drugs.

Common interactions include:

  • Drugs containing phenobarbital. (Primidone is similar to this drug, so taking them together can increase the risk of overdose or addiction.)
  • Herbal remedies containing St. John's Wort. (Can affect how this drug is cleared from your body and cause build-up and increased side effects.)
  • Hormonal birth controls. (Primidone may cause these birth control methods to fail. Always use additional contraception.)
  • Opioids like hydrocodone or codeine
  • Muscle relaxers like cyclobenzaprine
  • Antihistamines like cetirizine
  • Anxiety medications like lorazepam and alprazolam
  • HIV medications like darunavir and others
  • Alcohol
  • Marijuana
  • Ethanol

This list is in no way exhaustive. Make sure to speak to your doctor about your medications before beginning your Primidone treatment. Do not start taking any new medications while taking Primidone, and only do so with your doctor's approval. You should always make sure the drugs are not interactive before taking them together, and your doctor is your best source of personalized information.


This drug may be dangerous for people with certain conditions or diseases.

Primidone may cause changes in breathing. Use this drug with caution if you have asthma or other breathing conditions. If you have depression or a family history of depression, keep an eye on your mental health. If you experience any troubling changes, suicidal thoughts, or increased depression, speak to your doctor. Patients with bipolar disorder should also take note.

Do not take this drug if you have porphyria. This is a blood condition, and you should never take Primidone if you have this condition. You should speak to your doctor if this is not on file. Do not take this drug if you have an existing allergy to Primidone or any form of phenobarbital.

If you are pregnant, become pregnant while using this drug, or want to become pregnant, speak to your doctor about using this drug. Primidone may be harmful to an unborn child, but the risk of harmful seizures may affect both the mother and the baby. The pros and cons should be weighed carefully between the doctor and patient on a case-by-case basis. Additionally, breastfeeding mothers should exercise caution while using this drug, as it passes into breast milk. Bottle/formula feeding may be the safer option.

Your hormonal birth control may fail while using this drug. Always carry backup contraception like condoms or spermicide while taking Primidone, and inform your doctor if you think you might be pregnant. While you can continue taking your birth control, it should not be your primary form of contraception.

If you have been taking Primidone for a long period of time (a few weeks), you should not stop taking it abruptly. This can cause sudden seizures and serious complications. If you need to stop taking this drug, speak to your doctor and begin the step-down process. Neglecting to step down off this drug can be seriously harmful to your health.

This drug also comes with the risk of addiction. Talk to your doctor if you or your family has a history of addictive tendencies. You may require a lowered dose or close monitoring while you take this drug.

Always take this drug with caution, and stay in contact with your doctor while using this drug. Contact them if you experience issues, have questions, or want more information.


Some medications require special storage and handling. Primidone pills and tablets should be kept at room temperature. They should only be kept in a sealed container, and they should not be exposed to direct light and heat. Keep them from freezing, and do not store them in the fridge or freezer. Avoid keeping this drug in a humid or wet environment, as this may degrade the quality of the drug.

If you live with children or pets, do not keep this drug in un-lockable containers like weekly pill calendars. Find another way of remembering your doses, and keep this drug out of reach. Accidental consumption may result in overdose. If overdose occurs, call poison control and have the bottle on hand. Be ready to tell them how much was taken, when it was taken, and what the drug is.

If you need to dispose of this drug, do so responsibly. Do not throw away the pills loosely. Throw them away in their original bottle, another container, or a plastic bag. Dispose of them normally in a black/opaque trash-bag. Do not give this drug to anyone else for disposal.

Throw away any excess or expired medication. You should only take this drug as long as your doctor recommends it, and expired medication may be useless or harmful to you. If you need a refill, speak to your pharmacist or doctor to discuss getting additional medication. If your medication becomes wet or ruined, inform your doctor and request an early refill.

Do not give this drug to anyone else, even if their symptoms are the same as yours. If they require this drug, they should talk to their doctor for a prescription of their own. If you have concerns about how you should throw away this medication, look for authorized medication take-back programs in your area. They should be hosted by trustworthy pharmacies or hospitals.

More storage info may be found in your information leaflet, and your doctor may give you more detailed instructions on how to handle this drug. Only store and use this medication as advised.


For the general treatment of seizures and conditions that cause frequent seizures, Primidone may be prescribed to improve quality of life. As a barbiturate, this drug functions by controlling the electrical activity that occurs during a seizure. This drug may be used alone, or your doctor may prescribe it with other medications for a better treatment.

Primidone may cause side effects. These can be mild to severe in intensity. Always keep track of what side effects you experience, and report back to your doctor if they become intense, persistent, or severe. Nausea and drowsiness are two common side effects, and your doctor may manage them by prescribing an additional, non-interactive medication.

Interactions may occur, especially if the proper precautions are not followed. Always inform your doctor of what medications you are taking, whether they're over-the-counter, prescription, or herbal supplements. Your doctor may advise that you stop, switch, or lower the doses of your interactive medications. While unpleasant, it is for your own safety.

Do not use this drug if you are allergic to it, and only take the dose your doctor prescribes to you. A failure to do so may result in increased side effects, overdose, or the risk of addiction. If you need to stop taking this drug, do not stop your prescription abruptly. Doing so may cause stress to your body and extreme seizures. Talk to your doctor if you need to stop taking this medication, and work out a step-down plan.

If you experience staggering, vision changes, breathing changes, or changes in your mental condition, talk to your doctor and begin stepping down off this drug. These side effects, while rare, are symptoms of a larger problem. Primidone is not for everyone, so talk to your doctor if you begin experiencing these symptoms.

Primidone can be a powerful tool in seizure treatment. If you have frequent seizures, this drug may help to control your condition and prevent harmful seizures. Talk to your doctor if you think you may require this drug, and only take it with a doctor's supervision and approval.