What do we really know about the drugs we use to treat chronic pain?

Chronic pain can be extremely hard to treat in both humans and animals, and effective pain relief often requires the use of novel analgesic drugs. Little true scientific data actually exist for some of the drugs that we use to alleviate chronic pain, yet dosing protocols and expected results are available. The scientific data (pharmacokinetic/pharmacodynamic data) available for drugs used to treat chronic pain in veterinary patients will be presented along with published dosages and dosing guidelines.