WEDNESDAY, Oct. 19 (HealthDay News) -- An antiseizure drug called primidone (Mysoline) and a high blood pressure drug called propranolol (Inderal) are the most effective medicines to treat shaking in people with essential tremor, according to an updated treatment guideline from the American Academy of Neurology.

Essential tremor, which affects about 10 million people in the United States, is the most common type of tremor disorder and is often mistaken with other movement disorders such as Parkinson's disease.

The condition usually starts after age 40 and affects the hands, head and voice. It can cause difficulties with daily activities such as eating, writing, shaving and sewing.

Along with primidone and propranolol, other helpful medicines include the antiseizure drugs gabapentin (Fanatrex, Neurontin) and topiramate (Topamax), the high blood pressure drugs atenolol (Tenormin) and sotalol (Betapace, Sorine), and the anti-anxiety drug alprazolam (Xanax), according to the guideline.

Unlike the 2005 guideline, the updated guideline does not recommend the use of the antiseizure drugs levetiracetam (Keppra) and flunarizine (Sibelium) or the drug 3,4-diaminopyridine (used for rare muscle diseases) to treat tremors of the arms and legs.

The new guideline also noted that there is insufficient evidence to support the use of the schizophrenia drug clozapine (Clozaril). There is only weak evidence to support the use of the high blood pressure drugs nadolol (Corgard) and nimodipine (Nimotop), the antiseizure drug clonazepam (Klonopin), and botulinum toxin A (Botox).

For patients who don't benefit from drug treatment, two types of brain surgery -- deep brain stimulation and thalamotomy (involving the thalamus) -- may prove helpful, the guideline stated.

The guideline, endorsed by the International Essential Tremor Foundation, is published in the Oct. 19 online edition of the journal Neurology.

More information

We Move has more about essential tremor.