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Opioids BA%, T1/2, Tmax-duration superthread by Lorne???

Lorne???

Bluelight Crew
Joined
May 3, 2014
Messages
2,558
Ok, so we need to update the mega threads. The BA% megathread, in particular, is dreadfully outdated and has a lot of incorrect information; it also makes no attempt to address duration of action vs. t1/2, which are two different things.


So, am now attempting to provide updated information w/ a new list. Please, by all means, help out and add a reference and medication or figure. Any help is appreciated.
(Sdu= standard dosage unit, equal to roughly 10mg parenteral morphine)
So here we go:


Opioids:


Oxycodone: oral 35-87%, mean ~50% intranasal ~ 75%*, rectal about the same as oral Tmax 1.5-2hrs oral, <1hr nasal, 2-3hrs! rectal t1/2 variable, 2.5-7hrs, mean 3.4hrs (notes that this excludes rectal oxycodone, which has a delayed onset, and extended duration, and also lower plasma levels in proportion to BA% of dose) SDU- ~20mg oral,(15-30mg), 10-15mg IV/IM


References: A. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006196/


B.https://www.ncbi.nlm.nih.gov/m/pubmed/1485370/?i=3&from=/7818116/related
C.
https://www.ncbi.nlm.nih.gov/m/pubmed/7818116/


Should add another one or two


Buprenorphine: sublingual:varies 15-50% po: 10-15%~ intranasal: ~38-47% rectal 54%
T1/2: 1.5-7hrs mean ~3hrs IV/IM sublingual mean 28-37hrs
Duration: Long acting, medium to long IV/IM


Source(s) https://www.ncbi.nlm.nih.gov/m/pubmed/10354966/?i=2&from=/9048270/related


(Note YOU DO NOT NEED ETHANOL TO IMPROVE SUBLINGUAL BA%, a liquid solution is fine)


Methadone: rectal 70-80%, tmax 1.7hrs mean PO BA variable though high; mean >80%, tmax ~ 2-3hrs intranasal Tmax less than 15 minutes SDU varies; chronic methadone is more potent than a single dose

Oxymorphone: BA% 10-20% Tmax- =< 59 minutes(Opana ER tmax 1.5-3.5 hours) SDU P.O- 10-15mg
duration of action-3-8hrs (slightly longer than oxycodone)- more water and lipid soluble than oxycodone or morphine

Hydromorphone: BA- P.O ~50* (high variability) rectal ~34% nasal ~55% Tmax - P.O- ~1hr Rectal ~1.5 hrs intranasal 25 minutes *Multiple studies confirm this




https://www.ncbi.nlm.nih.gov/m/pubmed/15255797/?i=2&from=/12426517/related


Ok that is a start, hopefully will piece this thing together with progress in a day or two

https://www.ncbi.nlm.nih.gov/m/pubmed/11061578/
 
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Holy shit Lorne, one of your links may have solved the mystery of the methadone/conspiracy/poop/Zyrtec/nitrates/corn/liquid v solid thread!

I'll post it over there. Meanwhile, sounds good.

The biggest challenge, as always, will be formating.
 
Water solubiliies:

Oxymorphone: 250mg/ml lipid solubility- high

Hydromorphone: soluble in 3 parts water
Lipid solubility- high

Oxycodone: >150mg/ml lipid solubility-moderate

Morphine: Sulfate- <70mg per ml Lipid solubility-low

Diamorphine(H)- 500mg/ml(half a gram, so one gram of PURE diamorphine will dissolve in 2 parts water) lipid solubility: High*

Methadone: 120mg/ml, lipid solubility high

Fentanly-lipid solubility- very high
 
This is weird:

https://www.ncbi.nlm.nih.gov/m/pubmed/2453226/

and another study backs it up;

apparently hydromorphone rectal BA% isn't much of an improvement; ~34% according to a pair of studies, range 11-55%

P.O at 50? Of course BA doesn't translate directly into potency; Sublingual buprenorphine in liquid form can reach 50%, and even as tablets it is along the lines of 15-40%; yet UV buprenorphine is 5-10x as potent, because of rapid onset(although it takes ~15 minutes or more to peak) and, more importantly a MUCH higher Cmax and a much faster elimination, t1/2 3.4hrs vs ~12-40+ for sublingual

Still, 50%?(H-morphone BA%, by mouth) although rectal would have a faster onset and higher plasma levels, helping perhaps to explain the discrepancy

T1/2- 2-3hrs, phase 2 metabolism so unlikely to have a huge variance

This is just for a reference to something unrelated
 
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Hey Lorne.

I've been looking into morphine solubility quite a bit recently and read a load of stuff....Most places seemed to agree on a solubility in 22oC water of 60-64mg/ml for the sulphate or hydrochloride salt but as low as 50mg/ml...see below...Morphine base is ridiculously insoluble.....1 gram of morphine base in 5 litres of water


found this

Source.. International Journal Of Pharmaceuticals....January 1997.

The solubility limits of morphine hydrochloride (M) were determined as 50 mg/ml in water and 5% dextrose, and 30 mg/ml in 0.9% NaCl at 22oC, figures which decreased to 30 and 20 mg/ml, respectively at 4oC
 
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Interesting hydromorphone chart

Yeah BFTB, noticed differing figures; another interesting point was that hydromorphone had 10x the lipid solubility of morphine.

Thanks

Any and all contributions are highly appreciated for updating, and expanding our information, and hopefully megathreads

Oh, and it appears nearly all opioids have a delayed onset rectally, even highly soluble hydromorphone, although in some cases high interindividual variability plays a role in some cases
 
Opioid InfoDataDose MegaTable v. 1

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KLEINERkIFFER'S ANTI-OBFUSCATIONIST ODE TO OBDURANTOPIOIDS
[FONT=Calibri, sans-serif]THEOPIOID INFODATADOSEMEGATABLE[/FONT]
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[FONT=Calibri, sans-serif]Disclaimer:Nobody here is licensed to even drive, do not use this as medicaladvice[/FONT]


Opioids are a wide range of substancesthat act on opioid receptors (mu, delta, kappa, nociceptin). They canbe categorized into opiates (natural alkaloids found in the resin ofPapaver somniferum), semisynthetic (compounds of the poppy plant areused to synthesize new substances)and synthetic opioids (fullysynthetically produced). So all opiates are opioids, but not allopioids are opiates. Papaver somniferum has been used for hundreds,if not thousands of years, while moprhine was first isolated in the19th century and synthetic opioids were invented in the 20th century.Medical uses include pain, diarrhea and cough.


How do they work?
There are three main opioid receptors(mu (1-3), delta and kappa)
The mu receptor is responsible foranalgesia, physical dependence, respiratory depression, euphoria, andpossible vasodilation. Mu1 seems to be implicated in analgesia andmu2 in respiratory depression and physical dependence
The delta receptor is responsible forthe analgesia, antidepressant and convulsant effects as well asphysical dependence.
The kappa receptor is responsible forthe analgesia, anticonvulsant, dissociative and deliriant effects aswell as dysphoria, neuroprotection and sedation.
Opioids mimic the actions of endogenousopioid peptides by interacting with mu, delta or kappa opioidreceptors. The opioid receptors are coupled to G1 proteins and theactions of the opioids are mainly inhibitory. They close N-typevoltage-operated calcium channels and open calcium-dependentinwardly-rectifying potassium channels. This results inhyperpolarization and a reduction in neuronal excitability. They alsodecrease intracellular cAMP which modulates the release ofnociceptive neurotransmitters (e.g. substance P).
(https://www.ncbi.nlm.nih.gov/pubmed/9202932)


Dangerousinteractions
Don't combine with other depressants(like alcohol, benzos etc.) as they'll potentiate each other,increasing respiratory depression etc.
Adding stimulants can result inaccidental excessive intoxication
Don't combine with dissociatives
Some opioids shouldn't be combined withMAOIs/antidepressants


Good to know
Hormone imbalance
Opioid-induced hypogonadism seems to bea common complication of therapeutic or illicit opioid use.
(https://www.ncbi.nlm.nih.gov/pubmed/19333165)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4590093/
http://jaoa.org/article.aspx?articleid=2093682


Constipation
Constipation megathread


Attenuating tolerance withNMDA-antagonists









Oxycodone
Morphine equivalency: Oral 1.5 to 2 IV1
Full/partial agonist: Full MOR agonist
Onset of action: 10-30 minutes IR, 60minutes CR
Half life: 2 to 3 hours IR, 4 to 5hours CR
Duration of action: 3 to 6 hours IR, 8to 12 hours CR
Bioavailability of different ROAs: Oral60 to 87% Intranasal 45 to 77% IV 100%
Mode of action: MOR agonist. Talk ofKOR agonism is likely unfounded
Dosage: varies based on tolerance
Dangerous dosage: varies based ontolerance
Good to know: Metabolized primarily byCYP 3A4 to noroxycodone and CYP 2D6 to oxymorphone. Despite bothmetabolites being active, analgesia is produced mainly by oxycodoneitself due to poor CNS penetration of noroxycodone and only 10%converted to oxymorphone. Studies with poor 2D6 metabolizers haveshown little difference in pain relief compared to normalmetabolizers insinuating oxycodone and not oxymorpone produces theanalgesic effect.
Available in many dosage forms with orwithout acetaminophen (paracetamol) or NSAIDs. Most common would bePercocet (oxycodone + APAP, IR) 2.5, 5, 7.5, and 10mg/ 325 oxy/apap,IR oxycodone (various forms Roxicodone, Oxynorm) 5 to 30mg, andoxycodone ER/CR (Oxycontin 10 to 80mg) Available IV in some countries(UK) but not in US




Diacetylmorphine (Heroin)
Morphine equivalency: 2.5
Full/partial agonist: Full MOR agonist
Onset of action: Depending on ROA,within minutes
Half life: 2-3 min, morphine around 3h,6-MAM around 20 min
Duration of action: 4-5 h
Bioavailability of different ROAs: 5%oral, 44–61% smoked
Mode of action: Prodrug (lowµ-affinity), but mostly metabolism into 6-MAM and morphine
Dosage: 2.5-10 mg IV
Dangerous dosage. 20-25 mg IV
Good to know: Metabolized to morphinevia first-pass metabolism, via I.V. rapid crossing of BBB andmetabolized into 3-MAM (inactive) and 6-MAM (active) in the brain
Forms -> Black tar, ......




Sorted by potency from low to high


Tramadol
Morphine equivalency 0.1
Full/partial agonist: Fullµ-opioid-receptor agonist, low affinity
Onset of action: Orally IR 30-60min;Injected 20-45min; Orally XR 60-90min
Half life: around 6h, Metabolitesaround 9-10 hours
Duration of action: IR 6-10h; Injected6-9h
Bioavailability of different ROAs: Oral70–75%; Rectal 77%; IM/IV 100%
Mode of action: low affinity forµ-opioid receptor, SRI&SRA, Metabolite O-Desmethyltramadol hasa higher affinity for the µ-opioid receptor and NRI
Dosage: 25-100mg IR
Dangerous dosage: anything above 300mgcan lead to seizures, risk of respiratory depression is rather low
Good to know: Acts as SRI (primarymetabolite is a NRI) so combining it with SSRIs, MAOIs etc. canresult in Serotonin Syndrome; Lowers the seizure threshold, sodon’t go over 300mg; Main metabolite O-Desmethyltramadol hashigher affinity for the µ-opioid receptor and adds a lot to theeffects, so people with a CYP2D6 mutation making them poormetabolizers won't feel as much
those with decreased CYP2D6 activityrequire a dose increase of 30% in order to achieve the same degree ofpain relief as those with a normal level of CYP2D6 activity.(Wikipedia)


Codeine
Morphine equivalency: 0.1
Full/partial agonist: barely active onit's own
Onset of action: 15-60min
Half life: 2.5-6h
Duration of action: 4-6h
Bioavailability of different ROAs: Oralaround 50-90%; no other ROAs as it's a prodrug and IV can be lethal
Mode of action: barely active on it'sown, Metabolite Morphine full µ-opioid receptor agonist
Dosage: single dosage 0,5-1mg/kg BW;daily dosage 2-4mg/kg BW
Dangerous dosage: around 250-500mg, forfast metabolizers less
Good to know: Prodrug -> needs to bemetabolized into morphine; thus people people with a CYP2D6 mutationmaking them poor metabolizers won't feel as much/anything; InjectingCodeine can result in pulmonary edema (fluid in lungs), facialswelling and other life threatening complications as it provokes astrong histamine reaction, don't do it!; If you have acodeine-apap/ibuprofen/something else combo do a CWE




Tilidine
Morphine equivalency: 0.1-0.2
Full/partial agonist: Full agonist, butlow potency
Onset of action: 10-30min
Half life: 3-5h; Metabolites 3,5-5h
Duration of action: IR 4-6h; XR up to11-13h
Bioavailability of different ROAs: Oralaround 6-7%, IV 100%
Mode of action: only a really weakopioid on it's own, the active metabolites are mostly responsibly forthe effects (tilidine-> nortilidine-> bisnortilidine.Dextilidine seems to responsible for the analgesic activity
Dosage: single dosage 25-100mg; dailydosage 100-400mg
Dangerous dosage: 5-8mg/kg BW; above400mg
Good to know: Needs to be metabilizedvia the enzymes CYP3A4 and CYP2C19, thus people people with a CYP2D6mutation making them poor metabolizers won't feel as much/anything




Pethidine aka Meperidine
Morphine equivalency: 0,1-0.2
Full/partial agonist: Full MOR agonist
Onset of action:
Half life: 0,1-0.2
Duration of action: 2-5 h
Bioavailability of different ROAs:50–60% oral
Mode of action: MOR agonist, NET andDAT inhibition, interaction with sodium ion channels, muscarinicacetylcholine receptor antagonist , ?-opioid agonism
Dosage: 50 - 200 mg (other sourcestates 30-70 mg)
Dangerous dosage: > 210 mg ?
Good to know:Don't combine with MAOIsand antidepressants; Toxic metabolite, norpethidine, with an halflife of 8-12 (regular administration can lead to accumulation), hasconvulsant and hallucinogenic effects (probaply due toanticholinergic activity) and SRI effects




Dihydrocodeine
Morphine equivalency: 0.2
Full/partial agonist: Full MOR agonist
Onset of action: 0.3-1 h
Half life: 3-4 h
Duration of action: 3-5 h
Bioavailability of different ROAs:10-40 %
Mode of action: MOR agonist
Dosage: 50-250 mg
Dangerous dosage: >250 mg
Good to know: IV can lead toanaphylaxis and pulmonary edema, metabolites dihydromorphine (viaCYP2D6) and dihydromorphine-6-glucuronide have higher affinityes forMOR, but most likely only produced in small amounts




Hydrocodone
Morphine equivalency: 0.6 (in rhesusmonkeys higher than morphine; 1:1 with oral administered morphine)
Full/partial agonist: Full MOR agonist
Onset of action: 10-20 min
Half life: 3-5 h
Duration of action: 4-8 h
Bioavailability of different ROAs:60-70 % oral, 75 % rectal
Mode of action: MOR agonist, six timesless affinity for DOR
Dosage: 5-25 mg oral
Dangerous dosage: 50 mg oral
Good to know: Metabolized tonorhydrocodone (CYP3A4, but poor BBB-penetration) and hydromorphone(CYP2D6), around 40 % are metabolized via non,cytochrome-catalyzedreactions




Pentazocine
Morphine equivalency: 0.3
Full/partial agonist:agonist/antagonist maybe KOR agonist and MOR antagonist
Onset of action: 15-30 min
Half life: 2-5 h
Duration of action: 3-5 h
Bioavailability of different ROAs: highfirst pass metabolsim, so only 20 % oral
Mode of action: high first pass, soonly 20 % oral
Dosage: 20-50 mg
Dangerous dosage: 150 mg
Good to know: IV of pentazocine lactatemay lead to necrosis and sepsis, can be plugged (decrease dosage, asBA is higher), can increase BP and HR, may cause hallucinations anddelusions due to KOR agonism, has ceiling




Tapentadol
Morphine equivalency: 0.3 -0.6
Full/partial agonist: Full mOR agonist
Onset of action: 15-45 min
Half life: 4 h
Duration of action: 4-6 h
Bioavailability of different ROAs: 30%oral
Mode of action: MOR agonist and NRI
Dosage: 25-75 mg
Dangerous dosage:
Good to know: Don't combine with MAOIsand antidepressants, may lower seizure treshold, may causehypotension




Morphine
Morphine equivalency: 1
Full/partial agonist: Full MOR agonist
Onset of action: 10 s - 5 min (IV), 15min (IM), 20 min (PO)
Half life: 2-3 h
Duration of action: 3-7 h
Bioavailability of different ROAs: 20%to 40% oral, 36% to 71% rectal, 100% IV/IM
Mode of action: MOR agonist
Dosage: 10-20 mg oral, 2.5-5 mg IV
Dangerous dosage: 50 mg oral, 25 mg IV
Good to know: May lower seizuretreshold, high histamine release, may influence the production ofneutrophiles and cytokines (important for the immune system),endogenous opioid




Methadone (racemate)
Morphine equivalency: 2
Full/partial agonist: Full MOR agonist
Onset of action: 0.5 - 4 h oral, 0.3 -3 h rectal
Half life: 10-60 h
Duration of action: 4-12 h
Bioavailability of different ROAs:40-99 % oral
Mode of action: MOR agonist, weak NMDAantagonist, weak SRI, nicotinic acetylcholine receptor antagonist
Dosage: 3-15 mg oral
Dangerous dosage: 15 mg I.V., 20 mgoral
Good to know: Levo-methadone is twiceas potent; binds to and blocks hERG (alpha subunit of potassium ionchannel in the heart) thus can lead to Long-QT-syndrome, metabolsimvia CYP3A4 -> CYP3A4 can be inhibited by WGJ, don't combine withMAOIs and antidepressants




Hydromorphone
Morphine equivalency: 7.5
Full/partial agonist: Full MOR agonist
Onset of action: 20-60 min oral, 20 s -10 min IV
Half life: 2-3 h
Duration of action: 3-5 h
Bioavailability of different ROAs:30-50 % oral, 50-60 % intranasal
Mode of action: MOR agonist, may beweak kappa-agonist
Dosage: 1-4 mg oral
Dangerous dosage: 6-12 mg oral
Good to know: /




Oxymorphone
Morphine equivalency: 10-12
Full/partial agonist: Full MOR agonist
Onset of action: 10 s -10 min IV
Half life: 7-9 h
Duration of action: 3-6 h
Bioavailability of different ROAs: 10 %oral, 40 % intranasal
Mode of action: MOR agonist, may be DORagonist
Dosage:
Dangerous dosage:
Good to know: /




Buprenorphine
Morphine equivalency: 30-40
Full/partial agonist: Partial
Onset of action: 30 min
Half life: 20-70 h
Duration of action: up to 24 hours
Bioavailability of different ROAs: 30 %sublingual, 50 % intranasal
Mode of action: partial MOR agonist,DOR and KOR antagonist
Dosage: 0.2-0.8 mg
Dangerous dosage: ?
Good to know: high first-passmetabolism, ceiling and blocking effect, partial agonism -> highaffinity for receptor but low intrinsic activity




Fentanyl
Morphine equivalency: 120
Full/partial agonist: Full MOR agonist
Onset of action: 10 s - 5 min
Half life: depends on ROA, 3-12 h,longer with transdermal application, shorter with IV
Duration of action: depends on ROA
Bioavailability of different ROAs: 92%transdermal, 89% intranasal, 50% buccal, 3% oral
Mode of action: MOR agonist
Dosage: 12-50 µg ?
Dangerous dosage: ?
Good to know: metabolized by CYP3A4,little histamine release, high therapeutic index, half life mayincrease with repeated administration due to accumulation in muscleand fat-tissue due to high lipophilicity




Levorphanol*


Ketobemidone


Dipipanone


Propoxyphene*


Diphenoxylate*


Loperamide


Butorphanol*


Nalbuphaine


Dezocine


Remifentanil


Sufentanil


Carfentanil* (topical, was recentlyfound in heroin over here)


Etorphine









Antagonists


Naloxone
It's not a substitute for professionalmedical care, always call an abulance when someone overdoses!
Bioavailability: 2% oral due to highfirst-pass metabolism
Onset of action: 2-5 min
Half life: 1-1.5 h
Duration of action: 30-60 min
Mechanism of action: Non-selective andcompetetive opioid receptor antagonist, affinities mu(Ki 0.56nM)>delta(4.9 nM)>kappa (36.5 nM), (-)naloxone is active,(+)naloxone is pretty much inactive
Dosage: for IV/IM 0.4-2 mg, intranasal1-4 mg, maximum dosage 10 mg (if no response occurs at this time,alternative diagnosis and treatment should be pursued)
Good to know: In the United States,naloxone is classified as a prescription medication, though it is nota controlled substance. While it is legal to prescribe naloxone inevery state, dispensing the drug by medical professionals (includingphysicians or other licensed prescribers) at the point of service issubject to rules that vary by jurisdiction. In the following states,you can purchase naloxone from a pharmacist directly without gettinga prescription from a doctor: Alabama, Alaska, Arizona, Arkansas,California, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois,Indiana, Iowa, Kentucky, Maine, Maryland, Massachusetts, Minnesota,Nevada, New Hampshire, New Jersey, New Mexico, New York, NorthCarolina, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina,Tennessee, Texas, Utah, Vermont, Washington, West Virginia andWisconsin.
USA
UK




Naltrexone
Primarily used to manage alcohol/opioiddependence. For opioid dependence should only be taken afterdetoxification as it can cause precipitated withdrawal. Can be takenorally or IM. Competetive antagonist at the mu-opioid receptor (Ki0.0825 nM) > kappa (Ki 0.509 nM) > delta(Ki 8.02 nM). Half lifeof 4 h, active metabolite, 6ß-naltrexol, half life of around 13hours, depot injections/SC implants have considerably longer durationof action.
 
That looks better.

Come one come all and suggest all your edits and corrections, suggestions and dismissals, share your awe and/or your contempt.

This is a work in progress.
 
???

I have provided multiple references that contradict some of this data; Oxycodone BA% is ~50%, range range 35-87%

Diamorphine reaches 50-70% BA and is dose dependent; and a couple of other things

Ny data and, frankly facts should be integrated; Nice formatting, however

Would also mention that most opioids absorb slowly when plugged, though typically have a longer duration of action
 
Ok, just got comment above. Thank Yiu.

When get time integrate my information, it is referenced, multiple references in some cases

Like that you added Opioid receptor activity/possible activity, would add water solubility and (relative) lipid solubilities;

already have them, TFA
 
Hey, for now I am merely the formatman (point a to b). This table has its origins in a time before you and I could even pronounce benzodiazepine; years of research have passed since its inception. And I haven't even read it yet.

That's why we now open it up to you, the discerning public, to offer your suggestions and corrections, backed up with citations where necessary.
 
Yea^ missed your intro

An just willing to pull together some information for the sake of it

Thanks again for making it

And even I can't pronounce benzo, benzodiazepinin? Ah
 
Will try to find binding affinities;

note that oxycodone's binding affinity is surprisingly low, morphine's is ~5x higher, and DMT(Tramadol) has a similar affinity to oxycodone

Hydromorphone has the highest of the common morphinones, and it's lipid solubility is 10x higher than morphine; oxymorphone is right behind h-morphone, something like ~1nm for Hydromorphone and 1.5nm for oxymorphone;

Morphine was ~4.5 based on source, with 85% intrinsic activity; methadone was closer to 3nm, and IIRC ~90% intrinsic activity
Yet oxycodone greater than 20nm(note these figures vary by source) and codeine >1'000nm

Will try to add, though Tmax figures for this and benzodiazepines are likely priority

And clarifying what plugging actually does/ and how it effects pharmacodynamics

(delays absorption, which is surprising for things like Hydromorphone which is both water and lipid soluble)
 
???

I have provided multiple references that contradict some of this data; Oxycodone BA% is ~50%, range range 35-87%

Diamorphine reaches 50-70% BA and is dose dependent; and a couple of other things

Ny data and, frankly facts should be integrated; Nice formatting, however

Would also mention that most opioids absorb slowly when plugged, though typically have a longer duration of action

You mentioned this to me before (I wrote the oxy section). Forget the exact sources I used but it was several. But tend to now agree the BA range is too narrow. Ill change.
 
^ Thank You

Have a 2 references that say it averages 50%, and another that says 60%;

I know one says 87%, though, like you said, too narrow, Would go with ?35-87%? or something like that;

Can?t find it though another source gave wider figure

You do this and....

Well :)
 
Will try to find binding affinities;

note that oxycodone's binding affinity is surprisingly low, morphine's is ~5x higher, and DMT(Tramadol) has a similar affinity to oxycodone

Hydromorphone has the highest of the common morphinones, and it's lipid solubility is 10x higher than morphine; oxymorphone is right behind h-morphone, something like ~1nm for Hydromorphone and 1.5nm for oxymorphone;

Morphine was ~4.5 based on source, with 85% intrinsic activity; methadone was closer to 3nm, and IIRC ~90% intrinsic activity
Yet oxycodone greater than 20nm(note these figures vary by source) and codeine >1'000nm

Will try to add, though Tmax figures for this and benzodiazepines are likely priority

And clarifying what plugging actually does/ and how it effects pharmacodynamics

(delays absorption, which is surprising for things like Hydromorphone which is both water and lipid soluble)

I would also keep in mind that binding affinity data can vary considerably depending on the assay used
 
^ Check my post above from last/early morning; the link demonstrates the great variation in those figures

Really binding affinity is relative, IMO, it doesn?t belong in this thread

That?s why didn?t post benzodiazepine binding affinities in my crazy list

Although should mention Clonazepam?s is the highest...
 
Binding affinities are not relative, although they can vary depending on the method use to quantify Kd values, and that has more to do with differences in reaction conditions.

I don't quite understand how the linked paper demonstrates great variation in Kd values, although maybe I'm misunderstanding context.

I'm fine with having binding affinities, but it might be worth adding a disclaimer that they should be taken with a grain of salt since they don't necessarily correlate with potency.
 
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