Exotis ISSN 2398-2985

Reptiles

Trimethoprim-sulfadiazine / Trimethoprim-sulfamethoxazole

Synonym(s): Telazol, Zoletil

Contributor(s): Vetstream Ltd, David Perpinan

Introduction

Name

  • Trimethoprim/sulfonamide.

Class of drug

  • Potentiated sulfonamide antibiotic.

Description

Chemical name

  • Trimethoprim: 5 -(3,4,5-Trimethoxybenzyl)pyrimidine-2,4-diamine.
  • Sulfadiazine: 4-amino-N-pyrimidin- 2-yl-benzenesulfonamide.
  • Sulfamethoxazole: 4-Amino-N-(5-methylisoxazol-3-yl)-benzenesulfonamide.

Molecular formula

  • Trimethoprim: C14H18N4O3.
  • Sulfadiazine: C10H10N4O2S.
  • Sulfamethoxazole: C10H11N3O3S.

Molecular weight

  • Trimethoprim: 290.32.
  • Sulfadiazine: 250.27.
  • Sulfamethoxazole: 253.27.

Physical properties

  • Trimethoprim: odorless, bitter-tasting, white to cream-colored crystals or crystalline powder. Slightly soluble in water and slightly soluble in alcohol.
  • Sulfadiazine: odorless or nearly odorless, white to slightly yellow powder. Practically insoluble in water and sparingly soluble in alcohol.
  • Sulfamethoxazole: practically odorless, white to off-white, crystalline powder. Approximately 0.29 mg is soluble in 1 mL of water and 20 mg are soluble in 1 mL of alcohol.

Storage requirements

  • Store in tight containers at room temperature.

Uses

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Indications

  • Currently used less than in the past to treat parasitic and bacterial infections, as it is not particularly effective against many gram-negative bacteria affecting reptiles, and other drugs seem more effective at treating coccidial infections.
  • It may be useful to treat urinary, respiratory or systemic bacterial infections. Ineffective in the presence of necrotic tissue.
  • Coccidial infections: it may also be useful to treat cryptosporidiosis Snake parasitology overview (alleviate clinical signs and reduce oocyst shedding, but complete cure is unlikely).

Administration

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Pharmacokinetics

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Precautions

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Interactions

with other drugs

Warfarin
  • The anticoagulant effect of warfarin may be enhanced by trimethoprim/sulfonamide.
Antacids
  • May decrease the bioavailability of sulfonamides if administered concurrently.
  • Although sulfonamides may displace other plasma protein-bound drugs such as methotrexate, probenecid, thiazide diuretics and salicylates, the clinical relevance of such interactions is unclear. However, patients should be monitored for enhanced effects of displaced agents.

Adverse Reactions

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

Other sources of information

  • Meredith A (2015) Ed BSAVA Small Animal Formulary. Part B: Exotic Pets. 9th edn. BSAVA, UK. pp 338.
  • Plumb D (2015) Plumb’s Veterinary Drug Handbook. 8th edn. Wiley-Blackwell, USA. pp 1296.
  • Mayer J & Donnelly T M (2013) Clinical Veterinary Advisor: Birds and Exotic Pets. Elsevier, USA. pp 752.
  • Mader D R (2006) Ed Reptile Medicine and Surgery. Saunders Elsevier, USA. pp 1242.
  • McArthur S, Wilkinson R & Meyer J (2004) Medicine and Surgery of Tortoises and Turtles. Blackwell Publishing, UK. pp 579.
  • Girling S J & Raiti P (2004) BSAVA Manual of Reptiles. BSAVA, UK. pp 383.

Organisation(s)

  • National Office of Animal Health (NOAH) Compendium of Data Sheets for Animal Medicines. Website: www.noahcompendium.co.uk.

ADDED