Pharmacology - Strongest opioid

[car-ramrod]

So whats the most potent? PPOM has been proved stronger than etorphine in mice and carfent is used to immobilize elephants at a lower dose than etor as shown.

k) Jacobson,E.R., Heard,D.J., Caligiuri,R., and Kollias,G.V. 1987. Physiologic effects of etorphine and carfentanil in African elephants. Proc.1st.Intl.Conf.Zool.Avian Med. Pages: 525-527 Abstract: (Full text): The effects of etorphine hydrochloride and carfentanil citrate on blood pressure, heart rate, respiration and body temperature were determined in a group of captive African elephants. Fourteen African elephants, weighing 450 kg to 4000 kg, divided into 2 groups of 6 and 8 elephants each, received either etorphine hydrochloride (2.9 ± 0.7 µg/kg of body weight; mean ± SD) or carfentanil citrate (2.0 ± 0.2 µg/kg of body weight) respectively. The mean time for lateral recumbency in elephants which received etorphine was 31 ± 9.1 minutes while the mean time for lateral recumbency in elephants which received carfentanil was 10.3 ± 4.1 minutes. Following immobilization, a 18 gauge catheter was inserted into an auricular artery, the catheter connected to a pressure transducer system and systolic, diastolic, and mean arterial pressures were monitored by use of a multichannel oscilloscope. Systolic, diastolic, mean arterial pressures, heart rate, respiration, and temperature were recorded every 5 minutes over a 45 to 60 minute period. Elephants were maintained in lateral recumbency over the period of monitoring by intravenous injections of either etorphine or carfentanil.


Ill try to find tests on ohmefent analogues, Im sure its heads and shoulders above the rest.

3R,4S,beta-S)-13-fluoro ohmefentanyl is a mu-selective opioid with an in vivo analgesic/psychoactive potency measured as being almost 18,000 times that of morphine. Its ED50 in mice is about 800 nanograms/kg. As Professor Q notes, "there is a good chance that this compound could be made more powerful still, by addition of an alpha-methyl substituent. Although unlikely to increase affinity as such, it would greatly "harden" the agent against metabolic attack, since, as is the case with fentanyl, I would assume N-dealkylation of the piperidine to be the predominant pathway of liver microsomal breakdown. Even if ED50 doesn't go any lower, one would expect duration of action to increase by a factor of three or so.