Primor (sulfadimethoxine/ormetoprim) is a broad-spectrum antibiotic combination used to treat susceptible bacterial infections in dogs. Primor requires a prescription from your veterinarian, and is sold per tablet.
Primor is made up of two antibiotics
Do not use in pregnant or nursing animals. Your pet should be encouraged to drink plenty of water while being given Primor. Before giving Primor, be sure to tell your veterinarian what other medications or treatments your pet is receiving.
Primor Tablets (Pfizer Animal Health)
Primor is a prescription medication FDA-approved for veterinary use in dogs. Primor is available as scored tablets in two strengths: Primor 240 containing 200mg sulfadimethoxine and 40mg ormetoprim, and Primor 1200 containing 1000mg sulfadimethoxine and 200mg ormetoprim. The usual initial starting dose is 25mg/pound on the first day of treatment followed by 12.5mg/pound given once a day. Treatment should continue for 2 days after symptoms disappear. However, treatment should not exceed 21 consecutive days. Always follow the dosage instructions provided by your veterinarian. Do not give Primor to any pet other than the pet for whom it was prescribed. Primor is not for use in animals allergic to it or other sulfa drugs.
Primor is a potentiated sulfa drug used in dogs for the treatment of skin and soft tissue infections (wounds and abscesses), and urinary tract infections caused by susceptible bacteria. Primor may also be used for other conditions not listed.
Tell your veterinarian if your pet is allergic to Primor or other sulfonamides (sulfa drugs). Tell your veterinarian if your pet has liver disease or blood dyscrasias, is dehydrated, or is pregnant or lactating. Also tell your veterinarian what other medication, including vitamins and supplements, that you are giving your pet while giving Primor.
Give this medication exactly as directed by your veterinarian. Give Primor by mouth. It may be given with food. Leave plenty of water for your pet to drink. If you do not understand the directions ask the pharmacist or veterinarian to explain them to you. Store Primor at room temperature in a tight, light-resistant container. Keep this medication away from children and pets.
Give the missed dose as soon as you remember during the same day. However, if you don't remember until the next day, skip the dose you missed and give only the next regularly scheduled dose. Do not give a double dose of the medication.
Seek emergency veterinary medical treatment. Symptoms of overdose may include side effects listed below and may also include behavioral changes.
Antacids may decrease the effectiveness of sulfa drugs such as Primor. Give antacids 2-3 hours before or after giving a dose of Primor.
Sulfa crystals may appear in your pet's urine. Your pet should be allowed to drink plenty of water while taking this medication. Other side effects that may occur include KCS or dry eye, anemia, fever, loss of appetite, vomiting or diarrhea, joint inflammation, kidney damage, or skin rash. Stop the medication and contact your veterinarian if any of the above symptoms occur. Other side effects may also occur. Talk to your veterinarian about any side effect that seems unusual or bothersome to your pet. If your pet experiences an allergic reaction, signs may include facial swelling, hives, scratching, and sudden onset of diarrhea, vomiting, shock, seizures, or coma. If these signs occur, contact your veterinarian immediately.
Before giving Primor, tell your veterinarian if your pet is being given methotrexate, warfarin, phenylbutazone, thiazide diuretics, aspirin, probenecid, or phenytoin.
Your pharmacist has additional information about Primor written for health professionals that you may read.
If your pet shows no improvement after 2 or 3 days, have your veterinarian re-evaluate your pet's diagnosis. Treatment should not exceed 21 consecutive days.
Store this medication at room temperature away from moisture and heat.