Primor Tablet

Prescription Required
List: $1.24
Today's savings: 10%

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Temporarily Oversold. Please Order at a Later Date.



Temporarily Oversold. Please Order at a Later Date.

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All medications are filled by Pet's Choice Pharmacy. More information. Can only be shipped in the United States.

Orders placed using the Mail-In prescription option: please mail in your prescription within 14 days. If we do not receive your prescription within 14 days, your order will be cancelled and you will need to place a new order.

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Sometimes, manufacturers require that products be advertised only at their suggested prices. When we choose to sell these items for less, we display the sale price only in the cart. To see the price, click Add to Cart.

Product Summary:

Prescription items are NON-RETURNABLE and NON REFUNDABLE

Primor Indications For Use

Primor is for the treatment of skin and soft tissue infections (wounds and abscesses) in dogs caused by strains of Staphylococcus aureus and Escherichia coli and urinary tract infections caused by Escherichia coli, Staphylococcus spp., and Proteus mirabilis susceptible to sulfadimethoxine/ormetoprim. 


Primor is an antimicrobial drug containing sulfadimethoxine and ormetoprim in a 5 to 1 ratio. The combination of these 2 compounds results in the potentiation of sulfadimethoxine, providing increased efficacy, a broadened spectrum of activity to include some sulfonamide-resistant organisms, and reduction in the rate of resistance development. 

Sulfadimethoxine is a white, almost tasteless and odorless powder. Chemically, it is N1-(2,6-dimethoxy-4pyrimidinyl)-sulfanila-mide. The structural formula is:

 Ormetoprim is a white, almost tasteless powder. Chemically, it is 2,4-diamino-5-(4,5- dimethoxy-2methylbenzyl)-pyrimidine. The structural formula is:

Toxicity And Safety

1 Toxicity data for Primor indicates that the drug is safe when used at the recommended dosage. Following oral administration of Primor to dogs at 27.5 mg/kg/day (12.5 mg/lb/day) for 8 weeks, no changes were noted in hematology, blood chemistry, urinalysis, gross pathology, and histopathology, except for elevated serum cholesterol, increased thyroid and liver weights, enlarged basophilic cells in the pituitary, and mild follicular thyroid hyperplasia. These changes are known to be associated with prolonged administration of

sulfonamides to dogs and have been shown to be reversible. 

Adverse Reactions

Conditions reported following use of sulfonamides or potentiated sulfonamides include polyarthritis, urticaria, facial swelling, fever, hemolytic anemia, polydypsia, polyuria, hepatitis, vomiting, anorexia, diarrhea, and neurologic disorders. In rare instances, neurologic signs including behavioral changes, ataxia, seizures, aggression, and hyperexcitability have been reported. Keratitis sicca, possibly due to prolonged use of sulfonamides, has been reported. 

Individual animal hypersensitivity may result in local or generalized reactions. Anaphylactoid reactions, although rare, may also occur.


Epinephrine for anaphylactoid reactions. 


Decreased water consumption and aciduria enhance the probability of the formation of sulfonamide crystals in the urine. Monitoring urine samples for crystal formation is recommended from animals with acid urine receiving the drug. As with any sulfonamide therapy, make certain dogs maintain adequate water intake. If dogs show no improvement within 2 or 3 days, reevaluate the diagnosis. Safety in breeding dogs has not been established. 


Primor should not be used in dogs showing marked liver parenchymal damage, blood dyscrasias, or in those with a history of sulfonamide hypersensitivity. 

Primor Dosage And Administration

Administer an initial oral dose of 25 mg/lb (55 mg/kg) of body weight on the first day of treatment. Administer subsequent daily doses at the rate of 12.5 mg/lb (27.5 mg/kg) of body weight. Continue treatment for at least 2 days after remission of clinical signs. Do not extend treatment for more than 21 consecutive days. For optimal therapeutic effect: (1) the drug must be given early in the course of the disease; (2) therapeutically effective levels must be maintained in the body throughout the treatment period; (3) treatment should continue for at least 2 days after remission of clinical signs; and (4) the causative bacterial agents must be sensitive to the drug.

How Supplied

Primor is available as scored tablets for the following potencies: 120 mg, 240 mg, 600 mg, and 1200 mg. 


Store at controlled room temperature 15°-30°C (59°-86°F) 

Primor Caution

Not for human use. For use in dogs only. 


Keep out of reach of children.

Style Item Number Model Number UPC
120mg RX101026 120 012PFZ-120MG-TAB
240mg RX101026 240 012PFZ-240MG-TAB
600mg RX101026 600 012PFZ-600MG-TAB
Additional Information:

Please Note: 

This prescription product or therapeutic food is fulfilled by Pet’s Choice Pharmacy, Inc. A licensed pharmacy in all states, excluding North Carolina. Pet’s Choice is working with North Carolina Board of Pharmacy to be licensed to fill prescriptions in the future. We are only authorized to ship within the United States.  

To order prescription products or therapeutic foods must have an existing, valid veterinarian-client-patient relationship.  Prescription requests are subject to a Drug Utilization Review by a licensed pharmacist for patient safety. By law we can only accept a prescription faxed from your veterinarian or we must have the original prescription.

All prescription products (excluding therapeutic food) are FDA approved, or EPA licensed, to be sold in the US. Prescription products cannot be returned.  

Are we a licensed pharmacy?

The National Association of Boards of Pharmacy (NABP) has approved us as a Safe Site through its .pharmacy verified website program. We are not a licensed pharmacy; however, we are permitted to display pet medications on our site and have prescription orders fulfilled and delivered through our trusted partner, Pet’s Choice Pharmacy, an NABP .pharmacy verified website. This gives you a trusted and affordable alternative to purchase the medications your beloved pets need to maintain quality of life and overall health.

The .Pharmacy Verified program, prior to approval of domain registration, ensures that applicants meet all applicable Program Standards, which address regulatory standards including; to be licensed, registered, or hold appropriate permits where it is headquartered and where its customers reside, to protect patient medical and financial information and to have a clean disciplinary record.

To find out How to Fill your Pets Prescription click on More Information at the top. 

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