This occurs when a substance passes from the fluid in the tubular lumen through the apical membrane, across the cytosol , and then into the interstitial fluid.
Yes, it's potent stuff. Cat receive it either as an injection or orally. It takes effect in roughly half an hour, lasting about 8 hours before another administration is necessary. Cats usually react negatively to opiates, but buprenorphine is an exception. That's one reason vets use it if they can receive the necessary special certification.
Drug Information. Buprenorphine (BUP) is a prescription medication for people addicted to heroin or other opiates that acts by relieving the symptoms of opiate withdrawal such as agitation, nausea and insomnia. Buprenorphine is more weakly addictive and has a lower risk of overdose than methadone. The effects last for about three days. Buprenorphine is sold under the brand name of Subutex and, in combination with naloxone, as Suboxone.