Pseudo-phaeochromocytoma after multiple drug interactions involving the selective monoamine oxidase inhibitor selegiline.
A patient presented with paroxysmal hypertension and typical clinical features of phaeochromocytoma, but with a normal adrenal computed tomographic scan and much higher plasma noradrenaline than adrenaline concentrations. Urinary vanillylmandelic acid concentrations were only moderately elevated. This syndrome probably arose as a consequence of an interaction between the monoamine oxidase inhibitor selegiline, the sympathomimetic agent ephedrine, and a tricyclic antidepressant. The mechanism of the interaction is thought to be related to increased sympathetic release of noradrenaline by ephedrine, inhibition of catabolism by selegiline, and inhibition of reuptake of noradrenaline by the tricyclic. Although newer selective monoamine oxidase inhibitors are considered to be safer than earlier non-selective inhibitors, they can also contribute to drug interactions mimicking phaeochromocytoma.
Lefebvre
H
H
Department of Endocrinology, Centre Hospitalo-Universitaire de Rouen, France.
Noblet
C
C
Moore
N
N
Wolf
L M
LM
D001986:Bronchial Spasm / Q000188:drug therapy; D001991:Bronchitis / Q000188:drug therapy; D003866:Depressive Disorder / Q000188:drug therapy; D003937:Diagnosis, Differential; D004347:Drug Interactions; D004809:Ephedrine / Q000009:adverse effects; D004837:Epinephrine / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000139:chemically induced* / Q000175:diagnosis; D008297:Male; D008376:Maprotiline / Q000009:adverse effects; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010300:Parkinson Disease / Q000188:drug therapy; D010673:Pheochromocytoma / Q000139:chemically induced* / Q000175:diagnosis; D012642:Selegiline / Q000009:adverse effects*
D012642:Selegiline; D008376:Maprotiline; D004809:Ephedrine; D009638:Norepinephrine; D004837:Epinephrine