I am a 64 year old female who has been taking Primidone 250mg for about a year-3x daily. I had had a stroke in 2007 and the only residual affect was a tremor. I had also been taking propranolol with it for the tremor, I recently raised the dose of primidone and stopped the propranolol but raise the dose o primidone to 250mg plus an additional half tablet without calling my doctor. I requested an increase on my new prescription and was told my blood level 6 mos ago had been toxic. My heart is racing and my tremor (that had been less) is now worse-I am also on Xanax 1mg at same time of primidone dose. Have not called doctor to report this-do I just stop the primidone cold turkey??? I am almost out of it.