Hong Z, Olschewski A, Reeve HL, Nelson DP, Hong F, Weir EK. Nordexfenfluramine causes more severe pulmonary vasoconstriction than dexfenfluramine. American Journal of Physiology. Lung Cellular and Molecular Physiology. 2004 Mar;286(3):L531-8. PubMed
Ni W, Li MW, Thakali K, Fink GD, Watts SW. The fenfluramine metabolite (+)-norfenfluramine is vasoactive. Journal of Pharmacology and Experimental Therapeutics. 2004 May;309(2):845-52. PubMed