Dexfenfluramine or Fenfluramine + Other anorectics - Drug Interactions

Fenfluramine and dexfenfluramine have generally been withdrawn worldwide because of occurrence of serious and sometimes fatal valvular heart disease (aortic, mitral, tricuspid ormixed valve disease). Pulmonary hypertension has also sometimes been seen. These serious adverse effects occurred when these drugs were taken alone,and when combined with phentermine as Fen-phen and Dexfen-phen, but not with phentermine alone.(See reference number 1-5)There is also an isolated case of cardiomyopathy attributed to theuse of fenfluramine with mazindol.(See reference number 6)Before withdrawal of drug from market, manufacturer of fenfluramine recommended that concurrent use with other centrally acting anorecticsshould be avoided.(See reference number 7)

Committee on Safety of Medicines/Medicines Control Agency. Fenfluramine and dexfenfluramine withdrawn. Current Problems (1997) 23,12.

Food and Drugs Administration. FDA announces withdrawal fenfluramine and dexfenfluramine (Fen-Phen). September 15th,1997.

Connolly HM,Crary JL, McGoon MD, Hensrud DD, Edwards BS, Edwards WD, Schaff HV.Valvular heart disease associated with fenfluramine-phentermine. N Engl J Med (1997) 337, 581–8.

Mark EJ,Patalas ED, Chang HT, Evans RJ, Kessler SC. Fatal pulmonary hypertension associated with short-term use of fenfluramine and phentermine. N Engl J Med (1997) 337, 602–6.

Graham DJ,Green L. Further cases of valvular heart disease associated with fenfluraminephentermine. N Engl J Med (1997) 337, 635.

Gillis D,Wengrower D, Witztum E, Leitersdorf E. Fenfluramine and mazindol: acute reversible cardiomyopathy associated with their use. Int J Psychiatry Med (1985) 15, 197–200.

Ponderax Pacaps (Fenfluramine). Servier Laboratories Limited. ABPI Compendium of Datasheets and Summaries of Product Characteristics 1997–8,1307.