What is the difference between these two substances? By this, I mean how similar/different are they in chemical structure? Which one is stronger? Lastly, is morphine the same as heroin?
Sorry I tried searching but just pulled up instructional websites for drug abusers.
Heroin is diacetylmorphine, derived from the opium poppy. It’s rapidly metabolized in the body to morphine. If you ingest heroin, morphine is the most common metabolite found. Fentanyl is an opioid analgesic. It’s chemically unrelated to morphine, heroin or the other opiates, but it has some of the same euphoric and painkilling effects. Fentanyl is more powerful than morphine. A few years ago, heroin cut with fentanyl was being sold in the Midwest and caused a lot of overdose deaths.
Fentanyl is more powerful than morphine, but acts quicker and is shorter-lasting.
BTW, I was taught that fentanyl IS an opiate, specifically a mu agonist (like many others). And it seems to be backed up with my drug formulary.
that seems much more clear now, thanks!
Wikipedia also says that Fentanyl is “a strong agonist at the μ-opioid receptors.” I presume the same is true for heroin/morphine.
Often they call mu agonists that aren’t actually derived from opium “opioids” rather than “opiates.”
There are four categories of opiods (chemicals which activate the opioid receptors in the nervous system). There are the ones occurring naturally in your body such as endorphins and dynorphins, natural opiates which are found in opium such as morphine and methylmorphine (codeine), semi-synthetic opiates which are produced from natural opiates (probably the largest category) including diacetyl morphine (heroin), hydrocodone, and oxycodone, and synthetic opioids such as fentanyl and dextropropoxyphene - found in Darvocet. So not all opioids are opiates, fentanyl being an example. And not all target the mu opioid receptors either. Loperamide - found in anti-diarrhea medicine - targets another opioid receptor (I can’t remember which though I’m thinking kappa) causing constipation (the opposite of diarrhea) but no analgesia or high.
As for whether heroin or fentanyl is stronger, it takes a lot less fentanyl to get you high than heroin. Fentanyl is usually given to people with a high opioid tolerance. However, heroin supposedly offers a more euphoric high. (I’ve used neither drug but I’ve read accounts of people who have.) The primary way heroin works is it’s metabolized to morphine so it feels pretty much the same. However, it does penetrate the blood-brain barrier much more easily, allowing one to get high much more quickly.
I’ve given lots of fentanyl to opiate niave pts. We like it in the trauma rooms for it’s reduced tendency to cause hypotension and it’s short half life.
Common dosing would be~
dilaudid 1-2mg, morphine 2-10mg, fentanyl 50-100 mcg.
I’ll note that the dosage for heroin is about 2/3 that of morphine for the same effects, so it’s clear that it takes several times more heroin than fentanyl.