Take As Needed

Today I am giving a cat pain medication as needed. How am I supposed to know when it's needed? He's got a drain in his newly sutured tail and a cone on his head and he's locked in the laundry room. I'm thinking he needs pain meds all the time. Supposedly the medicine tastes terrible but he sucked down the last dose like it was mouse-flavored. Perhaps I waited too long but how am I supposed to distinguish a "pain" meow from a "I'm being a pain-in-the-ass" meow? And I just talked to the Vet who informed me that once or twice a day we need to twist the drain so it doesn't develop a scab. Great. I'm giving those pain meds about 15 minutes to kick in before I attempt that maneuver. And then I'm taking my own pain meds (i.e. glass of wine).