title: Short-term effects of tolvaptan on renal function and volume in patients with autosomal dominant polycystic kidney disease.
abstract: Tolvaptan and related V(2)-specific vasopressin receptor antagonists have been shown to delay disease progression in animal models of polycystic kidney disease. Slight elevations in serum creatinine, rapidly reversible after drug cessation, have been found in clinical trials involving tolvaptan. Here, we sought to clarify the potential renal mechanisms to see whether the antagonist effects were dependent on underlying renal function in 20 patients with autosomal dominant polycystic kidney disease (ADPKD) before and after 1 week of daily split-dose treatment. Tolvaptan induced aquaresis (excretion of solute-free water) and a significant reduction in glomerular filtration rate (GFR). The serum uric acid increased because of a decreased uric acid clearance, and the serum potassium fell, but there was no significant change in renal blood flow as measured by para-aminohippurate clearance or magnetic resonance imaging (MRI). No correlation was found between baseline GFR, measured by iothalmate clearance, and percent change in GFR induced by tolvaptan. Blinded post hoc analysis of renal MRIs showed that tolvaptan significantly reduced total kidney volume by 3.1% and individual cyst volume by 1.6%. Preliminary analysis of this small cohort suggested that these effects were more noticeable in patients with preserved renal function and with larger cysts. No correlation was found between changes of total kidney volume and body weight or estimated body water. Thus, functional and structural effects of tolvaptan on patients with ADPKD are likely due to inhibition of V(2)-driven adenosine cyclic 3',5'-monophosphate generation and its aquaretic, hemodynamic, and anti-secretory actions.
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Irazabal
authors.forename: Vicente E
authors.initials: VE
authors.lastname: Torres
authors.forename: Marie C
authors.initials: MC
authors.lastname: Hogan
authors.forename: James
authors.initials: J
authors.lastname: Glockner
authors.forename: Bernard F
authors.initials: BF
authors.lastname: King
authors.forename: Troy G
authors.initials: TG
authors.lastname: Ofstie
authors.forename: Holly B
authors.initials: HB
authors.lastname: Krasa
authors.forename: John
authors.initials: J
authors.lastname: Ouyang
authors.forename: Frank S
authors.initials: FS
authors.lastname: Czerwiec
mesh_terms: D000328:Adult; D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D003287:Contrast Media; D003404:Creatinine / Q000097:blood; D004231:Diuresis / Q000187:drug effects; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006727:Hormone Antagonists / Q000627:therapeutic use*; D006801:Humans; D007483:Iothalamic Acid; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D009929:Organ Size; D016891:Polycystic Kidney, Autosomal Dominant / Q000097:blood / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D011188:Potassium / Q000097:blood; D017483:Receptors, Vasopressin / Q000378:metabolism; D012079:Renal Circulation / Q000187:drug effects; D013997:Time Factors; D000077602:Tolvaptan; D016896:Treatment Outcome; D014527:Uric Acid / Q000097:blood; D010130:p-Aminohippuric Acid
chemical_list: D065092:Antidiuretic Hormone Receptor Antagonists; D001552:Benzazepines; D015415:Biomarkers; D003287:Contrast Media; D006727:Hormone Antagonists; D017483:Receptors, Vasopressin; D007483:Iothalamic Acid; D000077602:Tolvaptan; D014527:Uric Acid; D003404:Creatinine; D011188:Potassium; D010130:p-Aminohippuric Acid