Providing straightforward information pertaining to drugs, drug use & drug policy. The Grey Pages promotes drug-related literacy and advocates a system of viable and tolerant drug policies. This is my personal collection of commentaries, essays, tid-bits, and other such writings on everything ranging from drug use, drug policy and drug-myths, to drug-science, addiction, human behavior, and the workings of the human brain. I started this blog with a particular focus on opioids, and over the past year have found my interest gravitate toward the intriguing, ever-changing world of designer intoxicants (i.e. "research chemicals" or "designer drugs").

Friday, July 1, 2011

BuTrans - Equianalgesic Dosing

BUTRANS (Buprenorphine 7-Day Transdermal Patch)

BuTrans is available in three dosage strengths
It is interesting to note the poor transdermal absorption of the Butrans patch. According to clinical testing with the product, the relative bioavailability is approximately 15% wth each 7 day application. The manufacturer compensates adjusting the total patch content to roughly 6X the dosage of buprenorphine which would be expected - put simply, a 10ug per hour dose over 7 days (or 168 hours) would require a total of 1,680ug buprenorphine; but due to its poor bioavailability (15%) each transdermal unit is given a total of 10mg buprenorphine. This facilitates the systemic delivery of 10ug per hour, with the other 84% of buprenorpine in the product destroyed/wasted.

5ug per hour patch =
Equianalgesic to 0.16mg morphine/hour in vivo (0.48 oral)
~11.25mg morphine/day PO

10ug per hour patch =
Equianalgesic to 0.32mg morphine/hour in vivo (0.96 oral)
~22.5mg morphine/day PO

20ug per hour patch =
Equianalgesic to 0.64mg morphine/hour in vivo (1.92 oral)
~45mg morphine/day PO

40ug per hour (2 x 20ug/h units) =
Equianalgesic to 1.28mg morphine/hour in vivo (3.84 oral)
~90mg morphine/day PO

Terms to Know:

IN VIVO - "Inside of a live organism". In this context, in vivo refers to the equivalent systemic morphine dose, systemic meaning the amount which is fully active or bio-available to the CNS (brain, etc)

PO - Indicates the ORAL route

UG - MICROgrams . 1 Microgram is 1/1000 of a Milligram . Analgesic doses of buprenorphine are measured in micrograms, with 10ug being 0.01mg, and 100ug being 0.1mg and so on...