Veterinary Medicines

TMPS Oral Paste for Horses Potentiated sulfonamide antimicrobial.


Sulfadiazine 400 mg/g
Trimethoprim 86 mg/g


250g jar, 500g jar, 1kg tub


The combination of sulfadiazine + trimethoprim (TMPS) act synergistically to kill a wide range of susceptible bacteria and reduces the possibility of bacterial resistance developing.

The combination blocks the synthesis of bacterial folates at two critical points, which are essential for bacterial cell multiplication and survival. The combination of sulfadiazine + trimethoprim is bactericidal, while either drug alone is bacteriostatic. Folate synthesizing bacteria which are resistant or moderately resistant to either drug alone are frequently susceptible to the combination.

Randlab’s TMPS Oral Paste has a broad spectrum of activity against the common Gram-positive and Gram-negative bacteria including Staphylococci (including S. aureus and some strains of MRSA), Streptococci, Dermatophilus congolensis, Escherichia coli, Bacillus, Bordetella, Brucella, Corynebacterium, Fusiformis, Hemophilus, Klebsiella spp, Listeria monocytogenes, Nocardia, Pasteurella, Salmonella, Shigella and Proteus spp. (including S, aureus and some strains of MRSA).

The combination also has some effect against infections caused by protozoa (eg coccidia and Toxoplasma infection)

Infections caused by Leptospira, Psuedomonas, Mycobacterium and Erysipelothrix are generally not susceptible.

Randlab’s TMPS Oral Paste is useful in the treatment of respiratory infections, with high lung tissue levels achieved (although Airways Tmps and Bromo Tmps are designed specifically for respiratory infections), soft tissue infections, abdominal infections, joint infections, infections of the CNS, urinary tract infections and infections of the uterus/ placenta.

The bactericidal properties of Randlab’s Tmps Oral Paste may be reduced in the presence of pus and therefore should not be used for treating abscesses or infections caused by anaerobic bacteria.


TMPS is readily absorbed following oral administration with peak levels occurring about 1-4 hours after dosing. TMPS is widely distributed to all body tissues and fluids with levels similar to plasma found in pleural, peritoneal, synovial and ocular fluids with lower levels in CSF and muscle.

Both drugs cross the placenta and are present in the milk.

Sulfadiazine is excreted largely unchanged in the urine with higher levels than plasma present in the kidney and urine.


Horse Hack: Oral administration of trimethoprim+ sulfonamides may be associated with the development of severe, acute febrile diarrhoea in the horse.

The antibacterial actions of sulfonamides are reduced in the presence of blood, pus and tissue breakdown products as the bacterial requirements for folic acid is decreased in such media.

TMPS Should not be used in horses with marked liver parenchymal damage, blood dyscrasias or with a history of sulfonamide sensitivity.

Rarely TMPS may cause idiosyncratic neurological reactions consisting of behaviour changes, gait abnormalities and hyperaesthesia. These effects are reversed soon after discontinuing the medication.


Adult: 24-30mg/kg twice daily combined sulfonamide+ trimethoprim dose. (eg 30mg/kg =25mg/kg sulfadiazine + 5mg/kg trimethoprim).

Foals: 15-30mg/kg twice daily.

Dose rate equivalent to 5-6mL/100 kg twice daily (12 hourly). Administer directly into the mouth from a dosing syringe. To administer, place the syringe nozzle into the side of the horse’s empty mouth. Depress the plunger to deposit the paste as far back over the tongue as possible. Keep mouth closed for a few seconds to ensure that the dose is swallowed.

Whenever possible, bacterial culture and sensitivity testing should be carried out prior to initiating treatment with TMPS as well as in cases with non-responsive or chronic infections..


APVMA Approval No. 83452/119781 (Australia)

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