Selective serotonin reuptake inhibitor (SSRI) toxicosis in cats: 33 cases (2004-2010).

OBJECTIVE: To evaluate a population of cats with selective-serotonin reuptake inhibitor (SSRI) toxicosis and characterize the population affected, list products ingested, the clinical signs observed, treatments performed, length of hospitalization, patient outcome, and overall prognosis. DESIGN: Retrospective study from 2004 to 2010. SETTING: Referral veterinary center. ANIMALS: Thirty-three witnessed cat SSRI ingestions. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The medical records of cats with a witnessed SSRI ingestion identified by review of an animal poison control center electronic database were evaluated. The most common SSRIs ingested were venlafaxine (Effexor; 12/33; 36%), fluoxetine (Prozac; 12/33; 36%), citalopram (Celexa; 6/33; 18%), and escitalopram (Lexapro; 3/33; 9%). Overall, 24% of cats (8/33) became symptomatic, while 76% (25/33) remained asymptomatic. Of the symptomatic cats, sedation was the most common clinical sign (6/8; 75%), followed by gastrointestinal signs (4/8; 50%), central nervous system stimulation (1/8; 13%), cardiovascular signs (1/8; 13%), and hyperthermia (1/8; 13%). Veterinary care was sought in 20 cats (20/33; 61%). Sixteen cats (16/20; 80%) were hospitalized, while 4 cats (4/20; 20%) were treated as outpatients. Treatment for hospitalized patients included administration of IV fluid therapy (14/16; 88%), activated charcoal (12/16; 75%), anti-arrhythmic agents (7/16; 44%), methocarbamol (6/16; 38%), cyproheptadine (6/16; 38%), anti-emetics (5/16; 31%), and sedation (5/16; 31%). Diagnostics included blood work (7/16; 44%), blood pressure measurement (3/16; 19%), and electrocardiogram monitoring (2/16; 13%). Mean hospitalization time for all cases of SSRI ingestion was 14.6 ± 7.8 hours (n = 16). All symptomatic cats in this study (8/8; 100%) had resolution of clinical signs and survived to discharge. CONCLUSIONS: The prognosis for SSRI ingestion in this population of cats was excellent. Decontamination and supportive care for at least 12-24 hours can be considered in cats with SSRI ingestion, particularly venlafaxine to monitor resolution of clinical signs.