Desvenlafaxine: another "me too" drug?

Objective: To compare desvenlafaxine with its parent drug, venlafaxine, to determine the usefulness of this new medication.

Data sources: Information was obtained through a MEDLINE search (1966-June 2008) and from published abstracts. Search terms included desvenlafaxine, O-desmethylvenlafaxine, Pristiq, major depressive disorder, and venlafaxine.

Study selection and data extraction: All English-language studies and abstracts pertaining to desvenlafaxine and venlafaxine were considered for inclusion. Preference was given to human data.

Data synthesis: Desvenlafaxine is a serotonin-norepinephrine reuptake inhibitor and is the active metabolite of the antidepressant venlafaxine. The recommended dose is 50 mg daily, based on the efficacy and safety data of 50, 100, 150, 200, and 400 mg of desvenlafaxine. The response and remission rates of depression at 8 weeks for the 50-mg dose are 51-63% and 31-45%, respectively. These rates are comparable with those seen with venlafaxine (58% and 45%, respectively). Adverse effects are also similar to those of venlafaxine, with the most common being insomnia, somnolence, dizziness, and nausea. The decreased potential of CYP2D6 activity with desvenlafaxine compared with the parent drug may be a potential advantage in patients on other medications metabolized via this enzymatic pathway. Also, desvenlafaxine tablets are less expensive than extended-release (XR) venlafaxine, which may decrease healthcare costs in the short term. However, venlafaxine XR is expected to go off patent in 2010.

Conclusions: With the overall similarity between these 2 drugs and the potential lack of cost savings, the need for desvenlafaxine and its ultimate utility in treating major depressive disorder appears to be insignificant.