Fentanyl is a synthetic opiate analgesic similar to morphine. Fentanyl is 50-100 times more potent than morphine. It is prescribed mainly for patients with chronic pain and is generally used to manage pain after surgery. Fentanyl is prescribed as intravenous anesthetic (Sublimaze® ), transdermal patch (Duragesic® ), and transmucosal Lozenge form (Actiq® ). The fentanyl dose in the Duragesic ranges from 2.5-10 mg and in Actiq, it ranges from 0.2 mg-1.6 mg. Half-life of Fentanyl is 3-12 hours. Fentanyl is exclusively metabolized by N-dealkylation and hydroxylation. More than 90% of the dose is eliminated as norfentanyl and hydroxylated metabolites. Less than 7% of the dose is excreted unchanged in the urine.