Hoehe M, 1988. Influence on the menstrual cycle on neuroendocrine and behavioral responses to an opiate agonist in humans: preliminary results. PsychoneuroendocrinologyKeep an eye on Intently (2)primidone will reduce the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Watch Intently. Coadministra