title: Effects of orally administered moxaverine on ocular blood flow in healthy subjects.
abstract: BACKGROUND
  To investigate the effect of orally administered moxaverine (Kollateral forte®) on ocular blood flow in young healthy subjects.
  
  
  METHODS
  Sixteen healthy subjects (eight male/eight female) aged between 20 and 32 years were included in this placebo-controlled, double-masked, two-way crossover study. Volunteers received 900 mg moxaverine-hydrochloride administered orally in three equal doses or placebo identical in appearance on 2 study days. Outcome variables were measured at baseline and 5 h after first drug administration. Laser Doppler flowmetry was used to assess choroidal and optic nerve head blood flow. Blood velocities in the retrobulbar vessels were measured with color Doppler imaging.
  
  
  RESULTS
  Neither moxaverine nor placebo changed mean arterial pressure or intraocular pressure. Neither moxaverine nor placebo had an effect on choroidal (moxaverine: by 9.5 ± 17.2 %, placebo 3.8 ± 18.8 %, p = 0.54 between groups) or optic nerve head blood flow (moxaverine: 4.8 ± 10.4 %, placebo: 1.8 ± 10.9 %, p = 0.52 between groups). Similarly, administration of moxaverine did not change blood flow velocities or calculated resistance index in the retrobulbar vessels compared to placebo.
  
  
  CONCLUSIONS
  The data of the present study indicate that orally administered moxaverine does not increase ocular blood flow. This is in contrast to previous findings, where parenteral administration of moxaverine lead to a significant increase in choroidal blood flow and blood flow velocities in the retrobulbar vessels. The reason for these differing results is unclear, but may be related to the low bioavailability after oral administration.
authors.affiliation: Department of Clinical Pharmacology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
authors.forename: Doreen
authors.initials: D
authors.lastname: Schmidl
authors.forename: Berthold
authors.initials: B
authors.lastname: Pemp
authors.forename: Michael
authors.initials: M
authors.lastname: Lasta
authors.forename: Agnes
authors.initials: A
authors.lastname: Boltz
authors.forename: Semira
authors.initials: S
authors.lastname: Kaya
authors.forename: Stefan
authors.initials: S
authors.lastname: Palkovits
authors.forename: Franz
authors.initials: F
authors.lastname: Prager
authors.forename: Leopold
authors.initials: L
authors.lastname: Schmetterer
authors.forename: Gerhard
authors.initials: G
authors.lastname: Garhofer
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002829:Choroid / Q000098:blood supply*; D019842:Ciliary Arteries / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D009880:Ophthalmic Artery / Q000502:physiology; D009898:Optic Disk / Q000098:blood supply*; D010208:Papaverine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D010276:Parasympatholytics / Q000008:administration & dosage*; D012039:Regional Blood Flow / Q000187:drug effects; D012161:Retinal Artery / Q000502:physiology; D018615:Ultrasonography, Doppler, Color; D055815:Young Adult
chemical_list: D010276:Parasympatholytics; D010208:Papaverine; C004490:moxaverine