A Child Exposed to Primidone Not Prescribed for Her

Abstract

A 7.5-year-old girl who was treated with phenobarbital (PHB) for epilepsy was admitted with decreased levels of consciousness. She had been known to have high PHB levels of unknown cause, without symptoms. Her PHB levels were very high, as expected, but primidone levels were also detected although she and her parents denied history of primidone administration. We wished to rule out intentional unprescribed use of primidone. Our retrospective review showed 3 other children with high PHB concentrations where primidone was also detected when PHB levels were over 130 μmol/L. Complementary studies confirmed that high-dose PHB can convert to its prodrug primidone, which has not been reported previously.

Evaluation of the binding effect and cytotoxicity assay of 2‐Ethyl‐5‐(4‐methylphenyl) pyramido pyrazole ophthalazine trione on calf thymus DNA: spectroscopic, calorimetric, and molecular dynamics approaches

“…[16][17][18] Furthermore, this confirmed the possibility of converting high dosage of phenobarbital to pyrimidine. [19] Pyrimidine compounds are utilized in the treatment of different diseases such as vital tremor. The determination of the doses of these drugs is an important role in treatment with low side effects.…”

Antiepileptics

“…Brivaracetam was not found to have a significant difference in oral contraceptive metabolism or in break through bleeding at a dose of 100 …”

Primidone Intolerance in Essential tremor: Is it More than Just Age?

“…The half-life of primidone is 5-10 hours whereas the half-lives of PEMA (1-2 days) and phenobarbital (4-5 days) are substantially longer. Some reports suggest that phenobarbital, in high doses, through unknown mechanisms, can be metabolized back to its prodrug primidone [18]. The anti-tremor effect of primidone is usually apparent within one hour of oral administration and it peaks between 2 and 7 hours after administration.…”