Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
If you apply fentanyl transdermally, a greater proportion of the administered dose will be stored in the poorly perfused compartment (the subcutaneous compartment in this instance) because of the route of distribution.
You can't expect an iv bolus to proportionately reach the same degree of third-compartment redistribution in vivo.
In the former instance, you will end up with post-mortem redistribution that would multiply the ante-mortem iv measurement.
In the latter case, that figure would be considerably less (as yet unquantified).
If you disagree, find a study examining post-mortem redistribution after an iv bolus or oral dose.
Fentanyl is highly lipophilic therefore, fentanyl distributes to fat among other tissues. This stored fentanyl redistributes from fat to blood/plasma both pre and post-mortem from a slower passive gradient diffusion.
Quote:
The present study provides evidence that suggests that postmortem FB may not be reliable for the determination of the fentanyl concentration present at the time of death, ie, perimortem. Medical examiners and coroners need to be educated on the importance of this study’s observations before the use of blood fentanyl concentrations in cause of death interpretations.
Postmortem redistribution (PMR) refers to the changes that occur in drug concentrations after death. It involves the redistribution of drugs into blood from solid organs such as the lungs, liver, and myocardium. Drug properties such as volume of distribution, lipophilicity, and pKa are important factors. Basic, highly lipophilic drugs with a volume of distribution greater than 3 l/kg are most likely to undergo PMR.
hmm, i've always heard the best way first responder treatment for a drug overdose is to kneel on a guys neck for 9 minutes. Didn't they teach you that in med school?
Fentanyl is highly lipophilic therefore, fentanyl distributes to fat among other tissues. This stored fentanyl redistributes from fat to blood/plasma both pre and post-mortem from a slower passive gradient diffusion.
Lipophilicity is a factor in the rate of redistribution in vivo, but not in its direction post-mortem.
You need to defend the idea that post-mortem redistribution is peripheral-to-central irrespective of the route of administration. That means providing references that stratify findings based on mode of administration, which your sources don't do.
Your previous post mentions concentration gradients, which is actually more relevant to your argument.
We can discuss it from that point of view if that would be easier for you to understand.
Ive never heard of a way to measure someones tolerance to a particular drug.
The Science of Tolerance
Quote:
Several different body and brain mechanisms can contribute to the development of alcohol or drug tolerance, but with highly addictive substances, it happens at a cellular level. Morphine, for example, binds to and activates the nervous system’s opiate receptors, inhibiting an enzyme called adenylate cyclase. This inhibition causes several chemicals in the cell to maintain the firing of impulses. NIDA explains that “after repeated activation of the opiate receptors by morphine, the enzyme adapts so that the morphine can no longer cause changes in cell firing. Thus, the effect of a given dose of morphine is diminished.” In other words, the person has developed tolerance to morphine. Once a person has developed tolerance to a substance, their body and brain can become dependent on it.
Lipophilicity is a factor in the rate of redistribution in vivo, but not in its direction post-mortem.
You need to defend the idea that post-mortem redistribution is peripheral-to-central irrespective of the route of administration. That means providing references that stratify findings based on mode of administration, which your sources don't do.
Your previous post mentions concentration gradients, which is actually more relevant to your argument.
We can discuss it from that point of view if that would be easier for you to understand.
You need to read the research article I posted!
Key concepts in postmortem drug redistribution
Quote:
Postmortem redistribution (PMR) refers to the changes that occur in drug concentrations after death. It involves the redistribution of drugs into blood from solid organs such as the lungs, liver, and myocardium. Drug properties such as volume of distribution, lipophilicity, and pKa are important factors. Basic, highly lipophilic drugs with a volume of distribution greater than 3 l/kg are most likely to undergo PMR.
Medical toxicologists participating in forensic cases involving drugs likely to undergo PMR must be aware of its potential contribution to the postmortem drug concentration. Correlation with laboratory data and any available antemortem or perimortem clinical information is necessary to render an appropriate opinion on the cause of death.
Please register to post and access all features of our very popular forum. It is free and quick. Over $68,000 in prizes has already been given out to active posters on our forum. Additional giveaways are planned.
Detailed information about all U.S. cities, counties, and zip codes on our site: City-data.com.
Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
