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.
1. 6. Buprenorphine is used to ease withdrawal symptoms from opioids, and is an opioid partial agonist. Because it is a partial agonist, buprenorphine can cause the same or similar side effects as other opioids, including euphoria and respiratory depression.