title: Attenuation of the kaluretic properties of furosemide by triamterene (Dyrenium) in healthy volunteers.
abstract: OBJECTIVE
  To examine if concomitant administration of furosemide, a loop diuretic, with the potassium- and magnesium-sparing diuretic triamterene would decrease loss of potassium and magnesium while improving diuresis.
  
  
  METHODS
  In this open-label, three-way crossover study, healthy subjects were randomized to receive treatment with 40 mg furosemide, with 150 mg triamterene, or treatment with 40 mg furosemide and 150 mg triamterene. Urine samples were collected 24 hours before dosing and between 0 - 1, 1 - 2, 2 - 3, 3 - 4, 4 - 6, 6 - 8, 8 - 12, and 12 - 24 hours post-dosing. Sodium and potassium levels were measured by an ion-selective electrode method. Magnesium was measured colorimetrically using a xylidyl blue reaction.
  
  
  RESULTS
  Co-administration of furosemide with triamterene resulted in enhanced diuresis, particularly in the first 0 - 12 hours post-dose, compared with either furosemide or triamterene alone. Compared to individual treatments, combination therapy significantly increased urinary sodium excretion (p = 0.0001) while significantly decreasing urinary potassium excretion (p = 0.0001); importantly, the magnesium-sparing characteristic of triamterene was retained with furosemide co-administration.
  
  
  CONCLUSIONS
  Triamterene, when used in combination with the loop diuretic, furosemide, preserves intracellular potassium and magnesium while enhancing the natriuretic effect of furosemide.
authors.affiliation: WellSpring Pharmaceutical Corporation, Neptune, NJ 07753-6807, USA. blevin@wellspringpharm.com
authors.forename: B
authors.initials: B
authors.lastname: Levinson
authors.forename: M
authors.initials: M
authors.lastname: Shenouda
authors.forename: D
authors.initials: D
authors.lastname: Stypinski
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004231:Diuresis / Q000187:drug effects*; D004232:Diuretics / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005665:Furosemide / Q000494:pharmacology*; D006801:Humans; D008274:Magnesium / Q000652:urine; D008297:Male; D011188:Potassium / Q000652:urine; D012964:Sodium / Q000652:urine; D014223:Triamterene / Q000494:pharmacology*
chemical_list: D004232:Diuretics; D005665:Furosemide; D012964:Sodium; D008274:Magnesium; D011188:Potassium; D014223:Triamterene