How does actiq work for breakthrough pain?

Very short effect: For this reason this med shouldn't be used for non-cancer pain. The effect lasts for at most 1 to 1 hours. Tolerance develops rapidly because of the rapid, intense effect. This results in the need for higher and higher doses over a very short time. This med is most appropriate for patients not expected to survive for more than several months as the med becomes less effective rapidly.

It is an opioid: It is a fast onset opioid. It is indicated for break through cancer pain. The medication is absorbed through the mucosa of the mouth.