Q:

4/26/2013
I recently evaluated a patient with concern for anaphylaxis to duloxetine, a serotonin-norepinephrine reuptake inhibitor (SNRI). Are you aware of any drugs which are likely to be antigenically cross-reactive with duloxetine? I reviewed the structure of venlafaxine, another commonly used SNRI, which does appear quite different (i.e., a thiophene ring in duloxetine that is absent in venlafaxine, naphthalene moiety that is not shared, and other differences.) Many thanks for your help.

A:

Thank you for your inquiry.

As you mentioned, duloxetine is a dual serotonin-norepinephrine reuptake inhibitor. Other drugs in this class are desvenlafaxine, milnacipran, and venlafaxine.

Duloxetine, as you mentioned, is a naphthalene structure, both venlafaxine and desvenlafaxine are bi-cyclic phenethylamine compounds and are structurally related, and milnacipran is a phenylethamine. Duloxetine is not structurally related to the other drugs in this class (1, 2).

Thank you again for your inquiry and we hope this response is helpful to you.

References:
1) Norris S, Blier P. Duloxetine and milnacipran. In: The American Psychiatric Publishing Textbook of Psychopharmacology, Fourth Edition, Schatzberg AF, Nemeroff CB. (Eds), American Psychiatric Publishing, Inc., Washington, D.C. 2009. p.453

2) Thase ME, Sloan DM. Venlafaxine and desvenlafaxine. In: The American Psychiatric Publishing Textbook of Psychopharmacology, Fourth Edition, Schatzberg AF, Nemeroff CB. (Eds), American Psychiatric Publishing, Washington, D.C. 2009. p.439.

Sincerely,
Phil Lieberman, M.D.

AAAAI - American Academy of Allergy Asthma & Immunology