Possible Interaction: Morphine and Progesterone

“In a series of studies, Concas et al. show that acute and chronic administration of nicotine and morphine modulate both central and peripheral levels of progesterone , pregnenolone, and allopregnanolone (3α5α tetrahydroprogesterone; 3α-5α THP).”

“Animals treated with progesterone during late pregnancy and challenged with morphine during lactation exhibited a significant decrease in maternal behavior in both Experiments 2 and 3.”

“beta-endorphin (beta-EP) stimulated progesterone production in a dose-dependant manner (10(-8)-10(-6) mol/L); dynorphin exhibited a stimulatory effect only …/L, while Met-enkephalin had no substantial effect at dose from 10(-10)-10(-6) mol/L. mu-opioid receptor agonists DAGO and morphine … progesterone ….”

“ Chronic morphine treatment induced a supersensitivity state in the uteri from both progesterone and estradiol treated mice.”

“Administration of the opiate agonist, morphine , to estrogen/progesterone pretreated females decreased LH and decreased the depletion of the catecholamines in the above mentioned areas, suggesting reduced activity.”

“We now report that the intrathecal injection of morphine into female ovariectomized rats pretreated with oestradiol benzoate and progesterone inhibits sexual receptivity while injection of the opiate receptor antagonist naloxone enhances it.”

“ Morphine significantly increased brain and plasma concentrations of several steroids (including progesterone , deoxycorticosterone, corticosterone, and their metabolites) likely via activation of the hypothalamic-pituitary-adrenal stress axis.”