Gingival hyperplasia associated with the administration of amlodipine to dogs with degenerative valvular disease (2004-2008).
BACKGROUND
Calcium channel blocking drugs, usually nifedipine and less often amlodipine, have been reported to cause gingival hyperplasia (GH) in humans.


OBJECTIVE
Amlodipine, a dihydropyridine calcium channel blocking drug, can cause GH when administered chronically to older small dogs with degenerative valvular disease.


METHODS
From January 2004 to May 2008, 82 client-owned dogs with degenerative valvular disease and left atrial dilatation were treated with amlodipine in combination with spironolactone and enalapril and followed for >6 months.


METHODS
Retrospective study. A chronological observation of GH in 2 dogs treated with amlodipine in 2004 and 2006 prompted the study. Patient histories and medical records of each dog treated with amlodipine for degenerative valvular disease from January 2004 to May 2008 were reviewed.


RESULTS
GH was observed by clients and the authors in 7 of 82 (8.5%) dogs. Histologic confirmation of the diagnosis was made in 2 dogs. The minimum duration of treatment before diagnosis of GH was 5 months. GH began to resolve within 2 weeks of discontinuing amlodipine and resolution was complete within 6 months. Amlodipine administration was reinstituted in 1 dog in which GH had resolved, and GH reoccurred within 4 months.


CONCLUSIONS
Long-term administration of amlodipine to dogs with degenerative valvular disease may cause GH in a small percentage of patients. GH resolves quickly after withdrawal of amlodipine treatment.
Thomason
J D
JD
Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, USA. justin.thomason@okstate.edu
Fallaw
T L
TL
Carmichael
K P
KP
Radlinsky
M A
MA
Calvert
C A
CA
D017311:Amlodipine / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D000818:Animals; D002121:Calcium Channel Blockers / Q000009:adverse effects / Q000627:therapeutic use; D004232:Diuretics / Q000008:administration & dosage / Q000627:therapeutic use; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004656:Enalapril / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D005885:Gingival Hyperplasia / Q000139:chemically induced / Q000662:veterinary*; D006349:Heart Valve Diseases / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D012189:Retrospective Studies; D013148:Spironolactone / Q000008:administration & dosage / Q000627:therapeutic use
D000806:Angiotensin-Converting Enzyme Inhibitors; D002121:Calcium Channel Blockers; D004232:Diuretics; D017311:Amlodipine; D013148:Spironolactone; D004656:Enalapril