Title: Sulfamethoxazole/Trimethoprim | VCA Animal Hospital
Headings: Sulfamethoxazole/Trimethoprim
Sulfamethoxazole/Trimethoprim
By Rania Gollakner, BS, DVM, MPH
What is sulfamethoxazole/trimethoprim?
How is sulfamethoxazole/trimethoprim given?
What if I miss giving my pet the medication?
Are there any potential side effects?
Are there any risk factors for this medication?
Are there any drug interactions I should be aware of?
Is there any monitoring that needs to be done with this medication?
How do I store sulfamethoxazole/trimethoprim?
What should I do in case of emergency?

Content: Sulfamethoxazole/trimethoprim (brand names: Co-trimoxazole®, Primsol®, Bactrim®, Sulfatrim®, Novo-Trimel®, Septra®) is a potentiated sulfonamide antibiotic/antimicrobial used to treat certain infections such as bladder and prostate infections, Nocardia infections, or parasitic infections. Its use in cats, dogs, birds, reptiles, and small mammals to treat infections is 'off label' or 'extra label'. Many drugs are commonly prescribed for off label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully as their directions may be significantly different from those on the label. How is sulfamethoxazole/trimethoprim given? Sulfamethoxazole/trimethoprim is given by mouth with or without food in the form of a tablet or liquid suspension or solution. If your pet vomits or acts sick after receiving the medication on an empty stomach, give the next dose with a meal or treat. The liquid suspension should be shaken well before use and does not need to be refrigerated. There is also an injectable form that is used in exotic pets and given in the muscle or under the skin.