The self-adhesive unit contaning fentanyl hydrochloride is the size of a credit card, can be worn on the upper arm or chest. Fentanyl may also have an advantage over morphine in that it does not have active metabolites that can accumulate over time.

In a study with 636 adult postsurgical patients, patients were randomized to receive fentanyl hydrochloride by PCTS or IV morphine by PCA pump. Rates of withdrawal from the study were similar. Patient pain intensity scores were comparable between groups at all assessment times during the first 24 hours, as were their distribution within groups.