PHENOBARBITAL AND SSRIS
In one study in 6 subjects phenobarbital caused reductions of 10 to 86% in the AUC of paroxetine, but the mean values were unaltered. One subject showed a 56% increase in their AUC. Primidone is metabolised to phenobarbital and may therefore interact similarly with rifampicin.
Although there seems to be little correlation between plasma paroxetine levels and its efficacy, be alert for the need to increase its dosage if phenobarbital is given. Note that SSRIs can decrease the seizure threshold.
Although there seems to be little correlation between plasma paroxetine levels and its efficacy, be alert for the need to increase its dosage if phenobarbital is given. Note that SSRIs can decrease the seizure threshold.