What is the use of Primidone (anticonvulsant medication)?

From the Guidelines

Primidone is used to reduce the recurrence rate of febrile seizures in children, typically prescribed at doses of 15 to 20 mg/kg per day. The medication has been shown to be effective in preventing seizure recurrence, with some studies suggesting that primidone itself may be active in preventing seizure recurrence, even at derived phenobarbital levels below therapeutic range 1.

Key Points to Consider

• Primidone is an anticonvulsant medication that enhances the inhibitory effects of gamma-aminobutyric acid (GABA) in the brain, helping to reduce abnormal electrical activity.
• The medication is metabolized into phenobarbital and phenylethylmalonamide (PEMA), both of which contribute to its therapeutic effects.
• Common side effects of primidone include behavioral disturbances, irritability, and sleep disturbances, particularly in children 1.
• Despite its effectiveness, the potential toxicities associated with antiepileptic drugs like primidone may outweigh the relatively minor risks associated with simple febrile seizures, and long-term therapy is not recommended 1.

Clinical Considerations

• Primidone may be considered for use in situations where parental anxiety associated with febrile seizures is severe, although intermittent oral diazepam at the onset of febrile illness may be a preferred alternative 1.
• Regular monitoring of liver function and drug levels is recommended during treatment with primidone.
• Patients should be aware of the potential interactions between primidone and other medications, including oral contraceptives, anticoagulants, and other anticonvulsants.

From the FDA Drug Label

Primidone, used alone or concomitantly with other anticonvulsants, is indicated in the control of grand mal, psychomotor, and focal epileptic seizures. Primidone tablets are prescription medicine used alone or with other medicines to treat people with:

• generalized tonic-clonic (grand mal) seizures
• complex partial (psychomotor) seizures
• partial (focal) epileptic seizures

The use of Primidone is for the control of grand mal, psychomotor, and focal epileptic seizures. It is used alone or with other medicines to treat people with generalized tonic-clonic (grand mal) seizures, complex partial (psychomotor) seizures, and partial (focal) epileptic seizures 2, 2.

From the Research

Use of Primidone

• Primidone is used as an anticonvulsant medication to treat essential tremor, a prevalent movement disorder 3, 4, 5, 6, 7.
• It is classified as a clinically useful treatment for essential tremor, similar to propranolol and topiramate 3.
• The medication works by blocking voltage-gated sodium channels and modulating GABA-A and GABA-B intracortical circuits 4.
• Primidone is effective in reducing hand tremor severity, with its effects associated with decreased corticospinal excitability, prolongation of cortical silent period, and increased long interval intracortical inhibition 4.

Comparison with Other Treatments

• Primidone has been compared to propranolol in several studies, with both medications showing similar reductions in tremor severity 5, 6.
• However, primidone may have a faster onset of action, with significant reductions in tremor amplitude observed after only 2 doses 6.
• The choice between primidone and propranolol may depend on individual patient factors, such as tolerability and contraindications to beta-blockers 6, 7.

Clinical Considerations

• Primidone can cause acute adverse reactions, including nausea, vomiting, giddiness, and sedation, particularly at high doses 5, 6.
• Chronic side effects are less common with primidone compared to propranolol, but tolerance to the medication's effects can occur over time 5.
• The medication's efficacy and safety profile, as well as patient preference, should guide its use in clinical practice 3, 7.