Effect of penbutolol on neuroendocrine responses to buspirone and mood in SSRI-Refractory patients: A preliminary study
Clifford EM., Whale R., Sharp T., Cohen PJ.
The β-adrenoceptor antagonist, penbutolol, is an effective serotonin(1A) (5-HT(1A)) receptor antagonist in the rat and through this action enhances the ability of selective serotonin re-uptake inhibitors (SSRIs) to increase levels of serotonin in terminal fields. In healthy volunteers, penbutolol (40 mg orally), produced a modest attenuation of the prolactin response to the 5-HT(1A) receptor antagonist, buspirone (30 mg orally), but did not antagonise the hypothermic response. Furthermore, penbutolol addition (40 mg daily for 3 weeks) failed to improve the antidepressants. These preliminary data suggest that at the typical dose used to treat hypertension, penbutolol does not antagonise 5-HT(1A) autoreceptors in humans and does not augment the effect of serotonergic antidepressants in treatment non-responders.