Objective—To determine whether short-term amitriptyline
administration would be efficacious in the treatment
of acute, nonobstructive, idiopathic lower urinary tract
disease in cats.
Design—Randomized controlled trial.
Animals—31 untreated male and female cats with acute,
nonobstructive, idiopathic lower urinary tract disease.
Procedures—Cats were treated with amitriptyline (5
mg/d; n = 16) or a placebo (15) for 7 days and monitored
for pollakiuria, hematuria, and adverse events.
Cats were reexamined 1 month after treatment, and
owners were interviewed by telephone 6, 12, and 24
months after treatment.
Results—2 amitriptyline-treated cats were excluded
from analyses because of acquired urinary tract infection.
Clinical signs resolved by day 8 in 8 amitriptylinetreated
and 10 control cats. There were no apparent differences
in likelihood or rate of recovery from pollakiuria
or hematuria between groups. Overall, clinical signs
recurred significantly faster and more frequently in
amitriptyline-treated than control cats. However, after
excluding recurrences within 21 days of treatment, risk
of recurrence was similar in both groups. Increasing age
was significantly associated with increased likelihood
and rate of recovery from hematuria and with decreased
risk of recurrence of signs.
Conclusions and Clinical Relevance—Results suggest
that short-term amitriptyline treatment has no
benefit in terms of resolution of pollakiuria and hematuria
in cats with idiopathic lower urinary tract disease
and may be associated with an increased risk of
recurrence. (J Am Vet Med Assoc 2003:222:749–758)