Retinal effects of 6 months of daily use of tadalafil or sildenafil.
OBJECTIVE
To assess changes in electroretinography (ERG) and other retinal function parameters during 6 months of daily use of tadalafil, sildenafil citrate, or placebo.


METHODS
Subjects were randomized to use of a placebo (n=82), 5 mg of tadalafil (n=85), or 50 mg of sildenafil (n=77) daily for 6 months. Electroretinographs were recorded using the International Society for Clinical Electrophysiology of Vision (ISCEV) protocol and standardized ERG equipment at all 15 study sites. Other tests of ocular anatomy and visual function were performed at each assessment.


METHODS
The primary outcome was the average mean change for both eyes from baseline to endpoint in ERG b-wave amplitude using dark-adapted combined standard response to a bright ISCEV standard flash. Secondary endpoints were other ERG parameter changes, visual acuity, number of errors in color discrimination testing, mean deviation in automated visual field testing, and intraocular pressure (IOP).


RESULTS
No significant differences were found between treatment/placebo groups for the primary outcome, most other ERG variables, visual function, IOP, or anatomic assessments. The medications were well tolerated.


CONCLUSIONS
No abnormalities in ERG or visual function and no treatment-related findings suggestive of drug toxicity are associated with daily administration of tadalafil or sildenafil for 6 months.


CONCLUSIONS
Assessed visual safety of tadalafil/sildenafil administered daily over a prolonged period.


BACKGROUND
clinicaltrials.gov Identifier: NCT00333281.
Cordell
William H
WH
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA.
Maturi
Raj K
RK
Costigan
Timothy M
TM
Marmor
Michael F
MF
Weleber
Richard G
RG
Coupland
Stuart G
SG
Danis
Ronald P
RP
McGettigan
John W
JW
Antoszyk
Andrew N
AN
Klise
Suzanne
S
Sides
Gregory D
GD
D000328:Adult; D000368:Aged; D002243:Carbolines / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D004596:Electroretinography / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D010879:Piperazines / Q000008:administration & dosage* / Q000009:adverse effects; D011687:Purines / Q000008:administration & dosage / Q000009:adverse effects; D012160:Retina / Q000187:drug effects*; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000008:administration & dosage* / Q000009:adverse effects; D000068581:Tadalafil
D002243:Carbolines; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068581:Tadalafil; D000068677:Sildenafil Citrate