Possible Interaction: Capsaicin and Hexamethonium

“… capsaicin … hexamethonium (1×10−4 g/ml).5.Unaltered contractions were produced by capsaicin on ileal segments made tachyphylactic to 5-HT, bradykinin or substance P. ….6.It is concluded that in the guinea-pig ileum capsaicin causes predominantly cholinergic contraction by stimulating terminals of extrinsic, non-parasympathetic nerves.”

“The bronchodilation induced by capsaicin was significantly suppressed by hexamethonium and by L-NAME.”

“The excitatory effect of capsaicin on colonic motility was inhibited by atropine and hexamethonium.”

“A ganglionic-blocking dose (10 mg/kg) of intraperitoneal hexamethonium also significantly attenuates the gastric vasodilatory effect of intragastric capsaicin.”

“ Hexamethonium increased both Ch and the duration of RH and tended to reverse reductions in these parameters caused by capsaicin.”

“Ruthenium red (3-5 microM) antagonism of the inhibitory effect of capsaicin (1 microM) on the contractile response to mesenteric nerve stimulation in the presence of hexamethonium (50 microM) and guanethidine (2 microM) was reversed significantly by sialic acid (2 mM) or neuraminidase (0.1 U/ml).”

“The secretory response to capsaicin (80 nmol/kg ia) was completely blocked by atropine and hexamethonium , indicating that a cholinergic reflex mediates capsaicin-induced nasal hypersecretion in this model.”

“ Hexamethonium (0.7-1.2 mg/kg iv) prevented C-fiber stimulation by high-nicotine cigarette smoke (n = 12) but not stimulation by right atrial injection of capsaicin.”

“These responses were inhibited totally or mostly by capsaicin , administered neonatally, topically, or perineurally, by topical lidocaine, and by parenteral administration of substance P antiserum, somatostatin, or hexamethonium.”