Primidone (Systemic)

Brand Names : Myidone, Mysoline, Apo-Primidone, PMS Primidone, Sertan

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For primidone, the following should be considered:

Allergies - Tell your doctor if you have ever had any unusual or allergic reaction to primidone or to any barbiturate medicine (for example, amobarbital, butabarbital, pentobarbital, phenobarbital, secobarbital). Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy - Although most mothers who take medicine for seizure control deliver normal babies, there are reports of increased birth defects when these medicines are used during pregnancy. Newborns whose mothers were taking primidone during pregnancy have been reported to have bleeding problems. It is not definitely known if any of these medicines are the cause of such problems.

Breast-feeding - Primidone passes into the breast milk and may cause unusual drowsiness in nursing babies. It may be necessary for you to take another medicine or to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of the medicine with your doctor.

Children - Unusual excitement or restlessness may occur in children, who are usually more sensitive than adults to these effects of primidone.

Older adults - Unusual excitement or restlessness may occur in elderly patients, who are usually more sensitive than younger adults to these effects of primidone.

Other medicines - Although certain medicines should not be used together at all, in other cases 2 different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking primidone it is especially important that your health care professional know if you are taking any of the following:

• Adrenocorticoids (cortisone-like medicines) or
• Anticoagulants (blood thinners) - Use with primidone may decrease the effects of these medications, and the amount of medicine you need to take may change

• Central nervous system (CNS) depressants (medicine that causes drowsiness) - Using these medicines with primidone may increase the CNS and other depressant effects

• Oral contraceptives (birth control pills) containing estrogen - Primidone may decrease the effectiveness of these oral contraceptives, and you may need to change to a different type of birth control

• Other anticonvulsants (seizure medicine) - A change in the pattern of seizures may occur; close monitoring of blood levels of both medications is recommended. Use of valproic acid with primidone may cause increased CNS depression and other serious side effects

• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate]) - Taking primidone while you are taking or within 2 weeks of taking monoamine oxidase (MAO) inhibitors may prolong the effects of primidone and may change the pattern of seizures

Other medical problems - The presence of other medical problems may affect the use of primidone. Make sure you tell your doctor if you have any other medical problems, especially:

• Asthma, emphysema, or chronic lung disease - Primidone may cause serious problems in breathing

• Hyperactivity (in children) or
• Kidney disease or
• Liver disease - Primidone may make the condition worse

• Porphyria - Primidone should not be used when this medical problem exists because it may make the condition worse