Opiate Bioavailabilities

[Forthesevenlakes]

The bioavailability of a drug is the percentage of the drug that makes it from the route of administration into the bloodstream. Intravenous administration of a drug means that all of the drug is put directly into the blood, so the bioavailibility of IV is always 100%. With other routes (oral, insufflated/snorting, rectal, etc.), less of the drug reaches the blood due to incomplete absorption, metabolism in the liver before reaching the blood, etc. By knowing the route of administration swiy plans to use for a drug, and its dosage, swiy can estimate about how much of it will make it into the blood, and thus be available for the brain.

This thread will be a place to post bioavailabilities of opiates through different routes. Please cite sources when you contribute to this thread, and as I re-find the sources I used to make this I'll add them as links to the percentages!

Buprenorphine
Oral: 15%
Sublingual: 30%-50%
Intramuscular: 68%

Codeine
Oral: 60-90%
Rectal: about 90%

Dihydrocodeine
Oral: 20%

Fentanyl
Oral: 30%
Buccal: 50% (absorbed through the mouth lining, not swallowed)
Transdermal: 92%

Heroin
Oral: 35%
Smoked: 52%
Intramuscular: 85%

Hydrocodone
Oral: 50-60%

Hydromorphone
Oral: around 51.35%, some reports say 10-65% but this range is awfully wide.
Intranasal: 54.4%
Rectal: 36.33, up to 60% in the source I used.

Meperidine
Oral: 50-55%
Rectal: 55%
Intramuscular: 80-85%

Methadone
Oral: 70%-80%

Morphine
Oral: 40%
Insufflated: 10% alone, 60% with a chitosan solution. But SWIM thinks this number should be higher. Can anyone find any articles that give alternative measures?
Intramuscular: 70-70% estimated
Rectal: 70-90% One study says 27% in a parental solution, however!
Subcutaneous: 60%

Oxycodone
Oral: 60-87% (due to low first-pass metabolism).
Insufflated: One study says 45%. However anecdotal evidence says that it may be higher than this number.
Rectal: 61.6% in one study.

Oxymorphone
Oral: 10-20%
Insufflated: ~40%

Pentazocine
Oral: 20%

Propoxyphene
Oral: 30-70% (This is quite a wide range. SWIM suspects its closer to 30% but has no other sources at the moment to confirm this.)

Tramadol
Oral:70%

more to come later, please contribute if you have any info! Also keep in mind that everyone's body is different, and may metabolize and absorb drugs in different ways. These numbers are averages, so your milage may vary.

Reputation Comments on this post:

	very important points, well-researched
	Thanks for putting this together, albeit several years ago ;)
	Good topic to start a thread on
	very useful, stimulated good discussion

[bob78]

Swim would say Morphine's bioavailibility is quite high when insufflated, swim thinks there is quite a difference compared to being taken orally.

[Forthesevenlakes]

yes, swim has heard that it can increase the bioavailability of it from 3 to 6 times that of oral. chitosan, a type of polysaccharide, can apparently potentiate this but i dont have a source to confirm this at the moment.

swim is interested in finding bioavailabilities for heroin through the insufflation and smoking routes. can anyone find these?

also if you swims out there know any bioavailabilities for opiates i dont have up there, please help out and post them here!

[Riconoen {UGC}]

swim is pretty sure the bioavailability of hydrocodone through insuffulation is damn near zero but this is from personal experience. swim wiull try to find some sources erowid may have some.

[Forthesevenlakes]

snorting vicodin is not very efficacious because of the huge amounts of acetaminophen and fillers in them, if thats what swiy has tried. pure hydrocodone, as obtained from a CWE and evaporating the water at the end, may have better bioavailability. or that bioavailability figure might only be for a certain salt of hydrocodone, and swiy had a different form of it. thanks for looking for others, post them if swiy finds any!

[DrMuffy]

SWIM found a legitimate site which posted the bioavailability for rectal morphine doses, and the bioavailability is are somewhere between 70-90% Its because in your anal cavity or whatever u call it, has 1000 of veins to suck up the Morph, compared to hundred in your nose. I hope i helped

Reputation Comments on this post:

this finding was good, and swim is glad he's got someone helping him out on this thread =]

[Forthesevenlakes]

Originally Posted by DrMuffy

SWIM found a legitimate site which posted the bioavailability for rectal morphine doses, and the bioavailability is are somewhere between 70-90% Its because in your anal cavity or whatever u call it, has 1000 of veins to suck up the Morph, compared to hundred in your nose. I hope i helped

This logic makes sense. Absorption does tend to be better in the anal cavity for most drugs. SWIM is going to change the rectal bioavailability accordingly and look up that source for himself. His initial search yielded the 10-30% which did sound too low. Thanks!!

[Forthesevenlakes]

What other bioavailabilities should be included? Also, SWIM is having trouble locating bioavailibilities for non-oral routes of administration for hydrocodone and tramadol. If anyone could help, itd be much appreciated!

[Sklander]

SWIM thinks the bioavailability of Hydromorphone via rectal administration is higher than 36%... Probably in the 70% - 90% range, SWIM would imagine.

Anything taken rectally is going to have a substantially higher percentage of absorbtion compared to oral ingestion.

[Forthesevenlakes]

So true, swiSklander. SWIM is honestly wondering why he's getting such low numbers for the rectal route on his searches. Later today he'll look for another source to confirm swiy's report, and he'll add in this number right now. Thank you!

[Fantasian]

IM morphine is slightly less than that of IM Diamorphine.

SWIF would estimate at 70-77%

[pokeymcsmot421]

where did this up to 60% insufflated morphine # come from? with the chitosan solution up to 60%. anything ive read suggests around 10% other than that. http://cat.inist.fr/?aModele=afficheN&cpsidt=13571733

oral for oxycodone should be between 60% and 87%. http://gsm.about.com/compact/showmon...r=6078&match=F

hydromorphone has an oral to rectal ratio of 1:1.
average 33%. up to 60%.
http://www.medscape.com/viewarticle/493398

other than that looks good.

[Forthesevenlakes]

I think its came from people using the chitosan solution. But other things I've read state that its always about 6 times more bioavailable nasally than orally. Certainly the nasal route should be higher than the oral route. I'm starting to think its somewhere around 30%, but not sure. I want to find a non-chitosan paper that gives its bioavaliability.

[pokeymcsmot421]

i think it would also be interesting to see what peoples first hand opinion/experiences are.

swim has done morphine both orally and insufflated many manny times and it always works better when he insufflates, beyond placebo. But data is data.

also Swim thinks oxy insufflated works far better than oral and the data goes against that.

swim seems to feel theres some conflict between what should get someone more fuckd up and what actually does.

time of onset and intensity both could be major factors, as could placebo and ritual.

p.s. props for puttin a bioavailability thing together, good shit man.

[Forthesevenlakes]

it should more be said that "some data goes against that"...different studies could show that the nasal data is correct, and the oral data is too high. SWIM is wondering what it is about chitosan that could increase the insufflated bioavailability by six times though, thats impressive.

and the nature of the opiate itself, as well of time of onset and intensity could all contribute to what SHOULD work and what DOES work. set and setting play a huge role in this too.

[Citizen Kane]

@Forthesevenlakes: Very interesting pieces of information. Thanks for those. What are your sources if I may ask?

[Forthesevenlakes]

all types of research papers. I was using google alot. I hope to get an actual chart with many different types from some kind of publication, but so far I've just had to search drug by drug.

[Fantasian]

FTSL - Im sure that the bioavailablity for Buprenorphine isnt correct. I have no idea on the exact bioavailablities but there is definately a bigger margin from swallowed buprenorphine to sublingually taken buprenorphine.

[Forthesevenlakes]

I just work with what the research papers give me...I believe you, certainly, so if anyone can come up with a more realistic figure let me know.

[allyourbase]

SWIM is not sure about the scientific figures of bioavailability regarding morphine. SWIM can tell you this much. 90% is lost orally we all know this, one can eat a gram of opium and its ~ 8-9 mg of morphine on the brain. enough to feel, not enough to enjoy so much. now SWIM knows from SWIMs experience that one can take two thirds this, ingest it sublingually (again as latex) and it feels ~ like eating a gram. SWIM has snorted MS contins. SWIM had to snort 60 mg (!) to feel it at all. now by this "60% insufflated bioaivalability" qoute given above thats approx 24 mg on the brain. sure as HELL didnt feel like it, so SWIM must agree to disagree with those figures. these rascally ultra tertiary opiates. theyve been identified too long by our bodies as a poison and weve as a genetic whole built up this enzymatic tolerance to them. perhaps the best answer is to block the mitochrondrial enzymes destroying SWIYs morphine in the first place???? ahh forgot to read the base topic. SWIM does find that insufflation of dilaudid (that is hydromorphone bitartrate[?@ tartrate]) is approximately 1.25 times as effective as swallowing the pills.

[weekender2]

SWIM hasn't seen or heard any data regarding assing Hydrocodone - is that because it's not a great deal more bioavailable than taking it orally? Or that it's for some reason not a good idea? Or has he just missed it, in which case he'll apologize in advance?

Pax,
Weekender

[Forthesevenlakes]

It may just be that SWIM couldnt find a percentage for it. It should be more bioavailable rectally than orally, but by how much SWIM does not know, he suspects it might be close to oxycodone in its rectal availability. The dangers with hydro rectally would probably be roughly the same as with any opiate in that route, but its not a Bad Idea in that theres nothing that would be different with hydrocodone than another opiate, qualitatively. Failure to use caution, however, could make it quite dangerous, but SWIM is sure SWIY already knew that part of it!

[Wflash]

First off SWIM wants to congratulate the author of this thread on a lot of good research that can be of genuine use to the community on this forum.

But in the hope of adding something constructive, SWIM does want to add the following cautionary note.

It may be worthwhile to point out that some of the studies or citations used to derive the above bioavailability figures relate to particular pharmaceutical products, or particular means of drug delivery - rather than just the drug of itself.

As an example of what SWIM means – his understanding of the above is that the figure given for 50% buccal bioavailability for fentanyl is derived from a the prescribing information for a fentanyl product called Fentora – a product specifically designed for buccal administration.

It may therefore not necessarily follow that using other fentanyl products buccally will result in the same bioavailability.

In the same way that rubbing a Fentora tablet on the skin isn’t likely to give you the 92% transdermic bioavailability in the above list, putting a Durogesic transdermal fentanyl patch against the inside of your mouth might not necessarily result in the 50% bio-availability listed for that means of use.

SWIM’s sure this idea was a given for most when considering the above, but he thought it useful to add as it didn’t occur to him straight off.

SWIM confesses to beginning to think of this when experimenting with buccal use of post-legitimate usage non-gel Durogesic fentanyl patches. He hasn’t tried it many times as yet, but so far would suggest that only the speed of onset of the drug is much increased – not the strength of the effect that might be expected if 67% more drug was getting into his system.

[Forthesevenlakes]

Originally Posted by Wflash

First off SWIM wants to congratulate the author of this thread on a lot of good research that can be of genuine use to the community on this forum.

But in the hope of adding something constructive, SWIM does want to add the following cautionary note.

It may be worthwhile to point out that some of the studies or citations used to derive the above bioavailability figures relate to particular pharmaceutical products, or particular means of drug delivery - rather than just the drug of itself.

As an example of what SWIM means – his understanding of the above is that the figure given for 50% buccal bioavailability for fentanyl is derived from a the prescribing information for a fentanyl product called Fentora – a product specifically designed for buccal administration.

It may therefore not necessarily follow that using other fentanyl products buccally will result in the same bioavailability.

In the same way that rubbing a Fentora tablet on the skin isn’t likely to give you the 92% transdermic bioavailability in the above list, putting a Durogesic transdermal fentanyl patch against the inside of your mouth might not necessarily result in the 50% bio-availability listed for that means of use.

SWIM’s sure this idea was a given for most when considering the above, but he thought it useful to add as it didn’t occur to him straight off.

SWIM confesses to beginning to think of this when experimenting with buccal use of post-legitimate usage non-gel Durogesic fentanyl patches. He hasn’t tried it many times as yet, but so far would suggest that only the speed of onset of the drug is much increased – not the strength of the effect that might be expected if 67% more drug was getting into his system.

Excellent point. There are many factors which can influence bioavailability, and these are not always accounted for by presenting a simple number to the reader. The bioavailabilities are there as general guidelines, but many aspects of administration, other drugs taken, genetic and phenotypic differences, etc. can influence how much of a drug actually enters one's bloodstream and gets to the brain. Even with something as simple as a pill, taking an antacid will increase an opioid's bioavailability. If the pill is insufflated, mixing it in a water solution and spraying it in the nostrils might make it more bioavailable than simply crushing and snorting.

Taking into account these variations (which ones SWIY can be aware of, obviously nobody can account for everything) can help greatly in determining how a drug will affect SWIY, and what safety precautions SWIY should take.

This reminds me, SWIM still has to re-locate his sources for many of these numbers.

[Hard Rain]

This is anecdotal information from someone who isn't me, so SWIM does not have percentages, sorry.

From experience, SWIM doesn't think hydrocodone is that much more bioavailable rectally vs. oral administration, particularly when SWIM drinks the suspended hydrocodone in the water remaining from a CWE. SWIM feels that rectal administration of hydrocodone is a much shorter, and not significantly more intense, high vs. oral administration. Clearly all SWIMs are different.

SWIM does feel that Taramadol is significantly more bioavailable via rectal administration (tested with equal amounts). Again, no data to back this up, SWIM just felt there was faster onset and much stronger opiate sensations, although with a speedy edge. For example, oral tramadol provided barely noticable euphoric feelings, whereas rectal administration of the same mg resulted in euphora, chattiness, etc. that SWIM typically experiences while on Vicodin.