Methimazole

1,035 adverse event reports submitted to the FDA

Important: Adverse event reports do not establish that a drug caused or contributed to the event. Consult your veterinarian before making treatment decisions.

1,035

Total Reports

146

Deaths Reported

1410.0%

Death Rate

Active Ingredients

Methimazole

Administration Routes

UnknownOralTopicalTransdermalOtherAuricular (Otic)IntradermalIntratumor

Species Affected

Cat 1,017

Unknown 16

Dog 2

Most Affected Breeds

Domestic Shorthair 685

Domestic Longhair 96

Domestic Mediumhair 55

Cat (unknown) 46

Domestic (unspecified) 36

Siamese 30

Maine Coon 24

Unknown 17

Cat (other) 15

Persian 4

Most Reported Reactions

Vomiting 173

Weight loss 106

Anorexia 97

Lack of efficacy - NOS 93

Lethargy (see also Central nervous system depression in 'Neurological') 88

Not eating 86

Lethargy (see also Central nervous system depression in Neurological) 84

Death by euthanasia 82

Ataxia 69

Diarrhoea 68

Behavioural disorder NOS 59

Decreased appetite 58

Outcome Breakdown

Ongoing

382 (38.4%)

Outcome Unknown

233 (23.4%)

Recovered/Normal

218 (21.9%)

Euthanized

83 (8.4%)

Died

63 (6.3%)

Recovered with Sequela

15 (1.5%)

Source: FDA Center for Veterinary Medicine — Adverse Event Reports. Data reflects voluntary submissions and may not represent actual incidence rates.