PHENOBARBITAL AND TRICYCLICS

Barbiturates reduce the levels of the tricyclic antidepressants, which has been associated with the re-emergence of depression. Although not all combinations have been studied, they would all be expected to interact similarly.
Monitor the outcome of concurrent use anticipating reduced tricyclic antidepres- sant effects. Consider an alternative to the barbiturate, or raise the tricyclic dose if problems occur. Note that tricyclics lower the seizure threshold.