Butorphanol is a narcotic analgesic or a narcotic pain killer. In its tartrate form is a white, crystalline substance.

Dolorex, the new Merck Animal Health analgesia, is based on the active butorphanol.

In humans, butorphanol is most commonly administered for pain relief to people who have undergone surgery or to those who may have serious injuries and require pain management intervention.

The drug has gained wide acceptance, generating over $140 million in annual sales for Bristol Myers Squibb through brand names such as “Stadol NS”. It is usually delivered by injection. For the estimated 23 million migraine headache sufferers in America, butorphanol is administered as a nasal spray.

Butorphanol can either be prepared synthetically or from thebaine (chemical formula C19H21NO3), an alkaloid which occurs in opium (Papaver somniferum) and in certain of its preparations. It is indirectly related to morphine, but has very similar effects (agonist) and can be addictive. Butorphanol also has antagonist effects, meaning that it can the reverse the effects of some other opioid agonists.

With a pharmacological and therapeutic profile that has been well established since its launch as a parenteral formulation in 1978, butorphanol is a synthetic opioid agonist-antagonist analgesic.

Feature Benefit
Potent molecule Effective in moderate to severe pain
Few morphine-like side effects Less behavioral changes and other morphine related side effects
Registered for use in combination with alpha 2-agonist Lowers the dose, fewer side effects
Can be used intramuscularly as well as intravenously Provides a choice
Two presentations Provides a choice
Registered for use in dogs and horses Provides a choice
Butorphanol is a well-known molecule Molecule has proven itself
IV possible + characteristics molecule Rapid result
Short acting Repeat use possible
Characteristics molecule Less sedative effect than other opioids


How it works

Butorphanol acts in the brain to decrease the feeling of pain and to reduce the emotional responses to pain.