Possible Interaction: Arginine and Clonidine

“CONCLUSIONS If the combined simultaneous ar inine cl o nidine test we re shortened to 120 min, 5.2% of normal responders would be missed.”

“Compared to the arginine GH stimulation test, the clonidine GH stimulation displayed a higher sensitivity and specificity; combined GH stimulation test of clonidine plus arginine could significantly enhance the specificity in differential diagnosis of MSA-p from PD.”

“… clonidine … arginine were applied combined, the contrast of the maximal average GH concentration in serum in two groups was markedly increased (5.02 ± 1.12 vs. …) with a sensitivity and specificity of 73.91 and 92.31%, and the specificity was notably increased in the combined GH stimulation test.”

“Peak GH levels were lower with clonidine [mean +/- SE (micrograms/L): 9.79 +/- 1.29 ( arginine ) vs. 3.56 +/- 0.57 (clonidine) (P < 0.001)].”

“ L-Arginine did not alter morphine dependence but inhibited the effect of clonidine.”

“ L-Arginine did not alter morphine dependence, but at 20 mg/kg inhibited and at 100 mg/kg potentiated the attenuating effect of clonidine on the expression of withdrawal syndrome.”

“Intrathecal coadministration of L-arginine , substrate of NO synthase (NOS) or NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), dose-dependently reduced or potentiated, respectively, the antinociceptive effect of clonidine but not that of baclofen in the formalin test.”

“While, the early transient hypertension of clonidine was inhibited by pretreatment with L-arginine and later continuous hypotension was potentiated.”

“ Clonidine antinociception was enhanced by L-arginine and neostigmine, but not by D-arginine.”

“ Clonidine (0.1 mg kg-I, orally) caused a marked fall in systolic blood pressure in SH rats, less of a fall i n R H rats and least in DOCA rats.”