Bioavailability/Half-life MEGA Thread

[lyserg]

Alright guys our mission is to make an informative list of all chemicals, anything you came up with's bioavailability for oral, rectal, IV, IM and intranasal. Alright so lets all do some research and come back and collaborate on what info we have. Ill report back shortly!

All bioavailabilies are relative to IV bioavailability (100% ). For those that do not know, the bioavailability of a substance is basically the percentage of the dose that gets absorbed. It changes drastically for each method of administration. A half-life is the amount of time it takes for your body to eliminate half of the substance that you took. There is a lot of conflicting data on the exact bioavailabilities of each substance so every thing thats listed here is the average.

Opiates
Methadone: Oral 84%. Elimination half-life:24-36 hours,
Ketobemiodone: Oral 34% +/-10%; Rectal 44% +/- 9%. Elimination half-life: 2.25- 2.45 hours
Meperidine: Rectal 55%, IM 80-85% Elimination half-life 3.0 h
Buprenorphine: Oral 22%; Sublingual 30%; IM 90-100%. Elimination half-life: 12-44 hours
Hydromorphone: Oral-30-35%; Intranasal 52.4%; Rectal 33%
Dihydrocodeine: Oral 20%. Elimination halflife 4 hours
Heroin: Oral 35%; IM 85%
Fentanyl: Transdermal 92%; Sublingual and Buccal 50%; Intranasal 70%. Protein binding 80-85% Elimination half-life 3-12 hours
Sufentanil: Intranasal 78%,
Remifentanil: Protein binding 70%. Elimination half-life 1-20 minutes
Alfentanil: 92% Protein binding. Elimination half-life is 1.5-2 hours
Morphine: Oral 30%; Rectal 30%; Intranasal 15-20%, Chitosan(a linear polysaccharide that helps absorb drugs better) has been shown to increase nasal bioavailability of morphine from around 10-20% to over 60%, SC-60%, protein binding 30-40%, half-life is 2-3 hours
Oxycodone: Oral 60-87%; intranasal- 55-70%
Hydrocodone: Oral bioavailability is not really known but it is around oxycodone bioavailability; Orally 70% of it is usually absorbed, half-life is 4-8 hours
Oxymorphone: Intranasal 43%; Orals 10-20%; Rectal 10%
BUTORPHANOL : Oral 5-17%
Tramadol: Oral 68-72%; Rectal 77%: Eliminatio half-life 5-7 hours
Codeine: Oral 90%; Rectal 90%
Diphenoxylate: Protein binding 74-95%. Elimination half-life 12-14 hours
Pethidine(meperidine): Oral 50-60%. Protein Binding 65-75%, Half Life 3-5 hours
Normeperidine Is about half as potent as meperidine, but it has twice the CNS stimulation effects.
Pentazocine: Oral 20%. Half-life 2 to 3 hours

Opiate Antagonists
Naloxone: Oral 2-4%. Elimination half-life 1-1.5 hours
Naltrexone Oral 5-40%. Protein binding 21%, Half life-4 hours (naltrexone),
and 13 hours (6-β-naltrexol) (metabolite)

Benzodiazepines
Alprazolam: Oral 80-90%. halflife 9-20 hours
Bromazepam: Oral 84% half life 10-20 hours
Cinolazepam: Oral 90-100%, Half life 9 hours
Clobazam: Oral 90%. Elimination half-life 18 hour half life
Clorazepate: Oral 91%. Elimination half-life 36-100 hours
Chlordiazepoxide: Oral 100%; IM 90-95%. Elimination half-lives of its metabolites range from 14—100 hours
Clonazepam: Oral 90%; IM 93%
Diazepam: Oral 85-100%. Protein binding: 94% to 99%
Estazolam: Oral 93%. Elimination half-life 10-24 hours
Lorazepam: Oral 85-90%; Intranasal 78%
Midazolam: Oral 36-40%; Intranasal 55%, IM 90%
Flurazepam: Oral 83%. Elimination half-life is 40-250 hours
Temazepam: Oral 96%. Elimination halflife is 8-20 hours
Quazepam: Oral 29-35% Half life 39 hours


Other GABA acting drugs/ analogs
Gabapentin (Neurontin): Oral: lower doses absorb better at 60% for .9g daily dosing; 27% for 4.8g daily dose. Food increases absorbtion by 14%. Protein binding 3%. Elimination Half life 5-7 hours
Pregablin (Lyrica): Bioavailability 90%. Elimination Half life 5–6.5 hours
Vigabatrin: Oral 80-90%. Elimination half-life 5-8 hours in young adults, 12-13 hours in the elderly.

Buspirone:Oral 5%. Elimination half-life 2-3h

Stimulants
Methylphenidate: Oral 11–52%; Rectal is significantly higher, however an exact figure is not currently known. Elimination half-life 2–4 hours
Cocaine hcl: Oral 30%; Intranasal 40-60%. Elimination half-life .8-4 hours (depending on MOA)
Methamphetamine: Oral 62.7%; Intranasal 79%; Smoked 90.3%; 62.7%
Amphetamine: Oral 4L/kg; low binding to plasma proteins 20% Elimination half-life 10–13 hours
Ephedrine: Oral 85%. Elimination half-life 3–6 hours
Dextroamphetamine: Oral 75%. Elimination half-life 10-28 hours
Bupropron (Wellbrutrin: Oral 5-30%. Elimination half-life is 20 hours

Dissociatives/psychedelics
PCP: Oral 65%; Smoked 50%
Ketamine's: Oral 20±7%; IM 93%; Intranasal 25-50%; IV dose 96% and oral dose 20±7%. Ketamine is rapidly distributed into brain and other highly perfused tissues, and is 12% bound in plasma. The plasma half-life is 2.3 ± 0.5 hours.
MDMA: Elimnation half-life of the "S" isomer has a shorter half life (about 4 hours), whereas the "R" isomer has a much greater half life. (about 14hours)

Anti-depressants
Tianeptine: Oral 89 +/- 11%. Elimination half-life 2.5 hours
Trazodone: Oral 89 to 95%.

Muscle relaxants
Carisoprodol(soma): Oral 65%. 60% protein binding. Elimination half-life 8 hours
Meprobromate: Oral 60% protein binding. Elimination half-life is 10 hours
Baclofen: Protein binding 30%. Elimination half-life 1.5 hours
Dantrolene: Oral 70%

Sleep aids
Zolpidem: Oral 67%. 92% is bound in plasma
Zaleplon: Oral 30%. Elimination half-life is 1.1 hours
Diphenhydramine: Oral 86%. Protein binding 98 to 99%. Elimination half-life 1-4 hours
Eszopiclone (Lunesta): Protein binding 52-59%. Elimination half-life 6 hours
Zopiclone: Oral 52-59%. Bound to plasma protein. Elimination half-life 6 hours, and 9 hours for over 65


Barbituates
Hexobarbital: Oral 25%. Protein binding
Methohexital: Rectal 17%. Elimination half-life is 5.6 hours
Phenobarbital: Oral 95%. Protein binding 20-45%. Elimination half-life is 53 to 118 hours
Primidone: Oral 90%. Protein binding 70%. Elimination half-life of Primidone 5-15 hours, active metabolite (Phenobarbital) Elimination half-life- 100 hours

 

[jasoncrest]

BENZODIAZEPINES:

Routes of administration:

-Orally
All benzodiazepines can be taken orally, and have a great bioavailabilty this way.
(exemple: Diazepam oral bioavailability:85-100%, Protein binding: 94% to 99% )

-Rectally
All benzodiazepines except Chlordiazepoxide, Clorazepate (and surely Loflazepate too) can be taken rectally, and have a great bioavailabilty this way.

-Intranasal (snorted)
Only the following water-soluble benzos can be effectively snorted: Flurazepam, Midazolam, Loprazolam.

-Injection (IV/IM)
Unless you have ampoules for injection, only the following benzodiazepines can be prepared for injection with water only:
Flurazepam, Midazolam, Loprazolam.

*Note on Loprazolam: it is not completely soluble, but water-soluble enough to be effective when snorted or injected; this is also because you need a low dosage (1mg).

*Note on the inactive water-soluble benzodiazepines:
Chlordiazepoxide, Clorazepate Dipotassium (and Ethyl Loflazepate too I think) are water soluble, but they are inactive benzos, and need to be metabolized by some enzymes in your stomach into active benzos to give an effect. So these benzos can only be taken orally.
If injectable preparations of Clorazepate exist, it's because they contain a substance that makes the Clorazepate active.

 

[Pegasus]

dihydrocodeine 21% oral;
methadone 80% oral/ nasal; 76% rectal;
morphine 20-32% oral/ rectal; 10% nasal (non chitosan solution) 10% nasal (non chitosan solution) (2)
hydromorphone 50.7% +/- 29.8% oral; 33% +/- 22% rectal; 54.4% - 59.8% nasal
heroin 5% oral; 52% smoked
codeine 90% oral; 90% rectal
oxycodone 60 - 87% oral; 45% nasal, 50 - 60% nasal (2), 46% (25–67% ) nasal (3); widely varies nasally (notes on 50 - 60% study); rectal the same as oral
bupenorphine 15% oral; 31% sublingual; 90- 100% IM
meperidine 80% to 85% IM

cocaine 30% oral; 30-60% Nasal 57% Nasal (2); ~71% smoked
methylphenidate 11–52% (Oral); rectal is higher, but can't find a source
methamphetamine 79% nasal; 90.3% smoked; 62.7% oral; "67% of the estimated delivered dose or 37.4% of the absolute (pipe) dose after smoking. "
dextroamphetamine ~25% oral

alprazolam 80-90% oral
diazepam 90% oral/[URL="http://www.springerlink.com/content/acrq1nluwc10bj4w/fulltext.html#N1942"]rectal[/URL]
clonazepam 90% oral
lorazepam 90% oral; 77.7% nasal; 80% rectal
midazolam 75% oral; 55% nasal; 80 - 100% IM

phenobarbital 70-90% oral; 90% rectal

EDIT- If anyone disputes any of these that I didn't link to, let me know and I'll find the source. There shouldn't be any that are unbelievable though.

 

[jasoncrest]

Diazepam: 85-100% oral
Diazepam: 90% rectal

Lorazepam: 78% intranasal
Lorazepam: 90% oral

(all the interesting papers concerning the bioavailability of benzos can be read only if you pay...)

 

[Canis aureus]

What is the source (reference) of methadone oral 80%? I don't suspect its validity, just want to know where it's from... just beginning to slide in...

 

[raybeez]

I think adding references to the numbers given in this thread is going to become a neccessity when people start trying to 'dispute' them with heresay information they believe to be correct.

Jasoncrest: I have a paper that documents case reports of nasal abuse of benzos, specifically alprazolam and diazepam. A full text of the paper can be found here , but is annoyingly spliced with adds and page breaks.

Just because a benzo isn't water soluble, doesn't mean it can't be used nasally. Check out this thread, and this thread.

 

[Gaz_hmmmm]

Lyserg and JasonCrest, when you's say diazepam has a protein binding of 94% -99% what do you's mean?

 

[the unknown]

Oxycodone-oral 60-87%
oxycodone intranasal- 70%

oxycodone 60 - 87% oral; 45% insuffulated(source for people who doubt);

THOSE ARE VERY CONFLICTING . I dont care who did the study or whatever there is no way its 45% because i feel just as high as i do when i eat them. And i can say the same for almost everyone else. Why would so many people snort OCs, if the bioavailability its almost have that of oral, i think all those junkies would notice. I would def notice if i snorted 10mg and it only turned out to be 5mg or so. Whether i eat 10mg or snort 10mg of oxycodone it feels exactly the same th eonly difference is onset. Im sorry but the 45% is bullshit, i have to go with lyserg all day.

 

[jasoncrest]

Lyserg and JasonCrest, when you's say diazepam has a protein binding of 94% -99% what do you's mean?

I don't know exactly what it means, I just know that the protein binding % of a substance can indicate how fast and strong it kicks in.

What is the source (reference) of methadone oral 80%? I don't suspect its validity, just want to know where it's from... just beginning to slide in...

Why? You think it's higher than 80% or lower? Methadone has a very high oral bioavailability, that's all I know....

 

[Pegasus]

What is the source (reference) of methadone oral 80%? I don't suspect its validity, just want to know where it's from... just beginning to slide in...

It's on there now. There are a ton of sources saying 80%

THOSE ARE VERY CONFLICTING . I dont care who did the study or whatever there is no way its 45% because i feel just as high as i do when i eat them. And i can say the same for almost everyone else. Why would so many people snort OCs, if the bioavailability its almost have that of oral, i think all those junkies would notice. I would def notice if i snorted 10mg and it only turned out to be 5mg or so. Whether i eat 10mg or snort 10mg of oxycodone it feels exactly the same th eonly difference is onset. Im sorry but the 45% is bullshit, i have to go with lyserg all day.

Yes, well nasal administration varies quite a bit. 45 - 60% vs 60 - 87% isn't a difference I think most people would pick up on, especially with the oxy kicking in quite a bit faster through the nasal route.

I dont care who did the study or whatever there is no way its 45% because i feel just as high as i do when i eat them.

That's not very solid reasoning...

 

[raybeez]

I don't know exactly what it means, I just know that the protein binding % of a substance can indicate how fast and strong it kicks in.

Protein binding refers to the fact that some drugs form complexes with blood/plasma proteins, effectively "removing" the free drug from the blood. As the initial free drug is metabolised, and the plasma concentration of the drug begins to drop, the protein-drug complexes dissociate, releasing the drug back into the blood.

What does this mean? Compared to drugs with low protein binding, drugs that are highly bound by plasma proteins have much longer half-lives/duration of action, but 'peak' at a lower blood concentration.

 

[hussness]

Anyone have a figure for bioavailability of insufflated methylphenidate?

 

[Pegasus]

^I can't find anything but oral methylphenidate bioavailability, but I'm looking. I really want to know, too.

 

[the unknown]

That's not very solid reasoning...

Your absolutely right, its not solid reasoning. Tell me how the vast majority of people who use OCs snort them and feel it being equal to Oral. If the bioavailability was really that low then im sure the thousands of thousands of people who snort OCs whould realize it and no one would do it any more. I never ever heard anyone complain that they cant feel it as much when they snort it, as apposed to Oral. I just cant believe that study, im sorry. I have to agree with llysergs original bioavailability, it just makes sense.

 

[Canis aureus]

It feels about the same in oral or nasal, nasal comes just quicklier. (OXY)

You think it's higher than 80% or lower? Methadone has a very high oral bioavailability, that's all I know....

I believe that i've been reading it could be higher, indeed 90%. And it feels high, hahah.

 

[jasoncrest]

Your absolutely right, its not solid reasoning. Tell me how the vast majority of people who use OCs snort them and feel it being equal to Oral. If the bioavailability was really that low then im sure the thousands of thousands of people who snort OCs whould realize it and no one would do it any more. I never ever heard anyone complain that they cant feel it as much when they snort it, as apposed to Oral. I just cant believe that study, im sorry. I have to agree with llysergs original bioavailability, it just makes sense.

Oxycodone could have a 100% oral bioavailability, and a 50% intranasal bioavailability, some people would still snort it, because it kicks in quicker and stronger.

 

[Canis aureus]

Yep,

I'm sort of man who would wait that hour, hour or two, if better bioavailability; like I'm doing, LOL. Some wants it fast, some counts on numbers...

What would you do? (Addressed to all, just think, no need to answer!) Let's get back to availability...

 

[lyserg]

Carisoprodol(soma)-oral- 65% 60% protein binding
The plasma binding of PCP is 65%, smoked is 50%
Ketamines Bioavailability following an intramuscular dose is 93%, intranasal dose 25-50%, and oral dose 20±7%. Ketamine is rapidly distributed into brain and other highly perfused tissues, and is 12% bound in plasma. The plasma half-life is 2.3 ± 0.5 hours.

 

[Canis aureus]

Methadone is a synthetic opioid with potent analgesic effects. Although it is associated commonly with the treatment of opioid addiction, it may be prescribed by licensed family physicians for analgesia. Methadone's unique pharmacokinetics and pharmacodynamics make it a valuable option in the management of cancer pain and other chronic pain, including neuropathic pain states.

http://www.aafp.org/afp/20050401/1353.html

that source seems to rank morpphine to 26% oral, pretty low.


BollWeevil and all,

cocaine would be better in oral availablity, if mixed with sodium or lime...(?) and chewed (like leaf)... Wouldn't it be as high as in snorted, or still higher? I'm thinking about that that several sources says that all oral coke should be absorbted via mouth mucouses and based.

 

[Pegasus]

lyserg, where did you get that 70% figure for oxycodone insuffulated?