When you think of primidone, a barbiturate-derived anticonvulsant originally approved for epilepsy. Also known as Mysoline, it's been around since the 1950s and works by calming overactive nerve signals in the brain. Most people know it as a seizure drug—but that’s not all it’s used for. In fact, many neurologists and psychiatrists prescribe it off-label for conditions that don’t even show up on the official label. Off-label use isn’t illegal or shady—it’s common. About 20% of all prescriptions in the U.S. are off-label, and primidone is no exception.
One of the most well-documented off-label uses is for essential tremor, a neurological disorder causing rhythmic shaking, often in the hands. Studies show primidone reduces tremor severity in up to 70% of patients, sometimes as effectively as propranolol. It’s not the first choice for everyone—side effects like dizziness and fatigue can be tough—but for people who don’t respond to beta-blockers, it’s a solid backup. Then there’s anxiety, particularly severe, treatment-resistant cases. While SSRIs and benzodiazepines are the go-to, some clinicians use low-dose primidone for long-term anxiety control, especially when other meds cause weight gain or sexual side effects. It’s not FDA-approved for this, but case reports and small trials suggest it helps calm the nervous system without the risk of dependence.
Less common, but still reported, are uses for migraine prevention, where it acts similarly to other anticonvulsants like topiramate, and even bipolar disorder, as an adjunct when mood stabilizers aren’t enough. These aren’t first-line treatments, but for patients who’ve tried everything else, primidone can be a lifeline. It’s not without risks—liver enzyme changes, low sodium levels, and drowsiness are real concerns. That’s why it’s never started without monitoring and usually reserved for people who’ve failed other options.
The posts below dig into exactly how primidone stacks up against other seizure meds, what the real-world side effects look like, and how doctors decide when to use it for tremors, anxiety, or other unapproved uses. You’ll find direct comparisons with drugs like levetiracetam and valproate, real patient experiences, and clear guidance on when primidone makes sense—and when it doesn’t. No fluff. Just what you need to understand its full role in treatment.
Primidone is best known for treating seizures, but doctors increasingly use it off-label for essential tremor, anxiety, and nerve pain. Learn how this old, cheap drug works-and why it’s still effective when newer options fail.