Fentanyl volume of distribution is 4L/kg. For a 100kg person it distributes into 400L, or 400000ml. 11ng/ml would mean 4400000ng present in the body or 4.4mg. A 33% oral bioavailability means an oral dose of 13.2mg to achieve those blood levels.
If that’s a free level, it’s even higher of a dose. Since it’s 80-85% protein bound, a free level is only 15-20% of the total drug present in the body. Meaning an oral dose of at least 66mg.
For context, the transdermal patches deliver up to 0.1mg/hr. This dose is usually reserved for cancer patients who have developed resistance to other opioids and lower fent doses. The patch has 92% bioavailability so about 2.8x more drug makes it to the blood, meaning it achieves the same blood level as a 0.28mg oral dose. Since it is PER HOUR, that means the patch delivers the equivalent of 6.72mg orally over 24 hours.
In other words: assuming the PK data are accurate and 11ng/ml was a total fent level, Floyd took about 16hours worth of cancer patient fent all at once.
1mg is 1000000ng
Fentanyl volume of distribution is 4L/kg. For a 100kg person it distributes into 400L, or 400000ml. 11ng/ml would mean 4400000ng present in the body or 4.4mg. A 33% oral bioavailability means an oral dose of 13.2mg to achieve those blood levels.
If that’s a free level, it’s even higher of a dose. Since it’s 80-85% protein bound, a free level is only 15-20% of the total drug present in the body. Meaning an oral dose of at least 66mg.
For context, the transdermal patches deliver up to 0.1mg/hr. This dose is usually reserved for cancer patients who have developed resistance to other opioids and lower fent doses. The patch has 92% bioavailability so about 2.8x more drug makes it to the blood, meaning it achieves the same blood level as a 0.28mg oral dose. Since it is PER HOUR, that means the patch delivers the equivalent of 6.72mg orally over 24 hours.
In other words: assuming the PK data are accurate and 11ng/ml was a total fent level, Floyd took about 16hours worth of cancer patient fent all at once.