Primidone Side Effects

Brand Names: Mysoline

Please note - some side effects for Primidone may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Primidone - for the Consumer

Primidone

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Primidone:

Dizziness; drowsiness; incoordination; lightheadedness; loss of appetite; nausea; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); decreased sexual ability; double vision or unusual eye movements; fever; mood or mental changes; unusual tiredness or weakness.

Primidone Side Effects - for the Professional

Primidone

The most frequently occurring early side effects are ataxia and vertigo. These tend to disappear with continued therapy, or with reduction of initial dosage. Occasionally, the following have been reported: nausea, anorexia, vomiting, fatigue, hyperirritability, emotional disturbances, sexual impotency, diplopia, nystagmus, drowsiness and morbilliform skin eruptions. Granulocytopenia, agranulocytosis, and red-cell hypoplasia and aplasia, have been reported rarely. These and, occasionally, other persistent or severe side effects may necessitate withdrawal of the drug. Megaloblastic anemia may occur as a rare idiosyncrasy to Primidone and to other anticonvulsants. The anemia responds to folic acid without necessity of discontinuing medication.

Side Effects by Body System

Nervous system

Nervous system effects including ataxia and vertigo have been reported most frequently.

Ataxia and vertigo tend to disappear either with continued therapy or with the reduction of the initial dosage.

Gastrointestinal

Gastrointestinal effects including nausea, anorexia, and vomiting have been reported occasionally.

General

General effects including fatigue, hyperirritability, and drowsiness have been reported occasionally.

Psychiatric

Psychiatric effects including emotional disturbances have been reported occasionally. A case of primidone induced catatonic schizophrenia has also been reported.

Genitourinary

Massive crystalluria has also been rarely been reported following acute overdoses of primidone.

Genitourinary effects including sexual impotency have been reported occasionally. A case of massive crystalluria has been reported in a patient receiving maintenance doses of primidone.

Ocular

Ocular effects including diplopia and nystagmus have been reported occasionally.

Dermatologic

Dermatologic effects including morbilliform skin eruptions have been reported occasionally.

Hematologic

Hematologic effects including granulocytopenia, agranulocytosis, red cell hypoplasia, thrombocytopenia, and aplasia have been reported rarely. The manufacturer has reported that megaloblastic anemia may occur as a rare idiosyncrasy to primidone.

The anemia may respond to folic acid without the necessity to discontinue the primidone. The phenobarbital metabolite of primidone has been reported to have potentiated porphyrias.

Other

Rheumatologic side effects include drug induced lupus, frozen shoulder, and Dupuytren's contractures.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date, and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This information does not endorse drugs, diagnose patients, or recommend therapy. This drug information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug of drug combination is safe, effective, or appropriate for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of information provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse, or pharmacist.