Drugs and medications image
Drugs and medications image EquiMed


trye-chlor-muh-THYE-uh-zide - Pronunciation guide

Brand Names

  • Naquasone/compounded
  • Trichlormethiazide and Dexamethasone Bolus


Rx symbolTrichlormethiazide is an oral combination product marketed under the name Naquasone as a treatment for udder edema in cows. It is used to reduce mild swellings, especially in the legs of horses, by causing the body to lose water and sodium chloride by decreasing the reabsorption of these electrolytes in the kidneys.

An injectible form is also available in some countries.

In combination with dexamethasone, which is a potent anti-inflammatory, it should be used only under the supervision of a veterinarian who has made a proper diagnostic evaluation.

Trichlor/dexamethasone does not cure the underlying cause of the swelling.


Trichlormethiazide combined with dexamethasone is used to reduce mild swelling in the legs of horses. Because each component of the product works by a different mechanism, trichlor/dex contains a smaller dose of the individual drugs than might be used when administered separately.

Dosage and Administration

Prescription medicationTrichlormethiazide/Dexamethasone
Method Dosage
(click row for calculator)
Concentration Period Duration
Oral (Bolus) 0.44 mg/kg 200 mg/bolus 1 Daily NA
Intramuscular injection 0.5 ml/100lb 1 ml/ml 2 First day 2 injections, following days 1 injection 3 days


  • 1Each bolus contains: trichlormethiazide - 200 mg dexamethasone 10 mg
  • 2Each ml contains: trichlormethiazide - 10 mg USP dexamethasone acetate 0.55 mg USP
  • Federal law restricts this drug to use by or on the order of a licensed veterinarian.
  • Extra-label use of drugs in treating animals is allowable only by licensed veterinarians within the context of a valid veterinarian-client-patient relationship, and does not include drug use in treating animals by the layman (except under the supervision of a licensed veterinarian).
  • The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your equine appears to feel better, the entire treatment plan should be completed to prevent relapse.
  • This medication may be available in forms and concentrations not noted in the above table. Always check the label and literature provided with the medication about the form and concentration and DO NOT USE the calculator if the information differs.
  • Calculator is for educational purposes only. Follow your veterinarian's instructions regarding use of this, or any medication.

Side Effects

Trichlor/dex can mask signs of infection and should not be used when a bacterial infection is present or suspected without also treating the infection with appropriate antibiotics.


Dexamethasone is a corticosteroid and should be used with extreme caution in any horse prone to laminitis.

Trichlormethiazide is a diuretic and prolonged use can result in electrolyte depletion and dehydration. Free access to water and salt are important.

Trichlor/dex should not be used in pregnant or lactating mares unless the benefits outweigh the risks. This combination drug is rarely used in foals, but may be used in older horses without major health problems.

Trichlor/dex is not FDA-approved for use with horses, and is a prescription drug available only by or on the lawful written or oral order of a licensed veterinarian.

Trichlor/dex is prohibited in any drug-free competition. It is important to check with the appropriate regulatory group.


Trichlor/dex should not be used at the same time as other corticosteroids or diuretics.


Overdose will cause electrolyte depletion and dehydration. Free access to water and salt are important at all times.


Flogidem Trichlormethiazide Injection,   Flogidem Trichlormethiazide Injection,

Naquasone Trichlormedthiazide InjectionNaquasone Trichlormedthiazide Injection



About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.