Flumethasone

Corticosteroid Glucocorticoid

Dosage & Administration Guidelines

Species Route Dose Frequency Duration & Clinical Notes
Dog PO 0.05-0.1 mg/kg q12-24h Duration: Varies; taper after prolonged use
Notes: Use lowest effective dose; taper gradually to avoid HPA axis suppression.
Dog IV/IM/SC 0.05-0.2 mg/kg q12-24h Duration: Varies; for acute conditions, may be given once or for a few days
Notes: For shock, higher doses may be used (e.g., 2-4 mg/kg IV) but are not standard.
Cat PO 0.05-0.1 mg/kg q12-24h Duration: Varies; taper after prolonged use
Notes: Cats may be more sensitive to adverse effects; use lowest effective dose.
Cat IV/IM/SC 0.05-0.2 mg/kg q12-24h Duration: Varies; for acute conditions, may be given once or for a few days
Notes: For shock, higher doses may be used (e.g., 2-4 mg/kg IV) but are not standard.
Horse IV/IM 0.01-0.04 mg/kg q24h Duration: Varies; taper after prolonged use
Notes: For acute conditions, a single dose may suffice. Use caution in horses with laminitis risk.
Horse Intra-articular 2-5 mg per joint Single dose Duration: As needed
Notes: Use strict aseptic technique; avoid repeated injections.
Cattle IV/IM 0.02-0.05 mg/kg q24h Duration: Varies; taper after prolonged use
Notes: For ketosis, may be used as adjunctive therapy. Observe withdrawal times.
Small Ruminants (Sheep/Goats) IV/IM 0.02-0.05 mg/kg q24h Duration: Varies; taper after prolonged use
Notes: Use with caution; observe withdrawal times.
Rabbit IM/SC 0.05-0.1 mg/kg q12-24h Duration: Varies; taper after prolonged use
Notes: Limited data; use with caution.

Clinical Indications & Species Uses

General Indications
  • Anti-inflammatory and immunosuppressive therapy for various conditions
  • Adjunctive therapy for shock and cerebral edema
Dog (Canine)
  • Inflammatory and allergic conditions (e.g., dermatitis, pruritus, allergic reactions)
  • Autoimmune diseases (e.g., immune-mediated hemolytic anemia, immune-mediated polyarthritis)
  • Musculoskeletal inflammation (e.g., arthritis, bursitis)
  • Shock (as an adjunctive therapy)
  • Cerebral edema
  • Neoplasia (palliative treatment for spinal cord compression)
Cat (Feline)
  • Inflammatory and allergic conditions (e.g., dermatitis, asthma, allergic reactions)
  • Autoimmune diseases (e.g., immune-mediated hemolytic anemia, inflammatory bowel disease)
  • Musculoskeletal inflammation (e.g., arthritis)
  • Shock (as an adjunctive therapy)
  • Cerebral edema
Horse (Equine)
  • Inflammatory and allergic conditions (e.g., allergic dermatitis, urticaria, chronic obstructive pulmonary disease (COPD) or heaves)
  • Musculoskeletal inflammation (e.g., arthritis, bursitis, tendinitis)
  • Shock (as an adjunctive therapy)
  • Cerebral edema
Cattle (Bovine)
  • Inflammatory and allergic conditions (e.g., allergic reactions, respiratory disease complex)
  • Musculoskeletal inflammation (e.g., arthritis, laminitis)
  • Ketosis (as an adjunctive therapy)
  • Shock (as an adjunctive therapy)
  • Cerebral edema
Small Ruminants (Sheep / Goat)
  • Inflammatory and allergic conditions (e.g., allergic reactions, dermatitis)
  • Musculoskeletal inflammation (e.g., arthritis)
  • Ketosis (in sheep and goats, as an adjunctive therapy)
  • Shock (as an adjunctive therapy)
Rabbit & Small Mammals
  • Inflammatory and allergic conditions (e.g., dermatitis, allergic reactions)
  • Musculoskeletal inflammation (e.g., arthritis)
  • Shock (as an adjunctive therapy)
Exotic & Other Species
  • Reptiles: Inflammatory conditions (limited data)
  • Small mammals (e.g., ferrets, guinea pigs): Inflammatory and allergic conditions (limited data)

Pharmacology & Mechanism of Action

Drug Class: Corticosteroid | Pharmacological Group: Glucocorticoid

Mechanism of Action: Flumethasone is a potent synthetic glucocorticoid with anti-inflammatory, immunosuppressive, and antipruritic properties. It binds to the glucocorticoid receptor, leading to modulation of gene expression. This results in inhibition of phospholipase A2, reduced production of pro-inflammatory cytokines (e.g., IL-1, IL-6, TNF-α), decreased prostaglandin and leukotriene synthesis, and suppression of immune cell function (e.g., neutrophils, macrophages, lymphocytes). It also induces lipocortin synthesis, which inhibits phospholipase A2, and stabilizes lysosomal membranes, reducing inflammation and tissue damage.

Pharmacodynamics: Flumethasone has a rapid onset of action and is approximately 30 times more potent than cortisol. It exhibits strong anti-inflammatory and immunosuppressive effects, with minimal mineralocorticoid activity. It suppresses the hypothalamic-pituitary-adrenal (HPA) axis, leading to decreased endogenous cortisol production. It also affects carbohydrate, protein, and fat metabolism, promoting gluconeogenesis, protein catabolism, and lipolysis. Its potency and duration of action vary by species, with a longer duration in dogs and cats compared to horses and ruminants.

⚡ Pharmacokinetics Summary

Absorption: Flumethasone is well absorbed after oral, intramuscular, and subcutaneous administration. After oral administration, peak plasma concentrations are reached within 1-2 hours. After IM or SC injection, absorption is slower and more prolonged, providing a longer duration of action.
Distribution: Flumethasone is widely distributed throughout the body. It crosses the placenta and is distributed into milk. It is highly bound to plasma proteins, primarily corticosteroid-binding globulin (CBG) and albumin. It penetrates well into tissues, including the central nervous system, but its distribution is influenced by the degree of protein binding.
Metabolism: Flumethasone is metabolized primarily in the liver via reduction, oxidation, and conjugation. The metabolites are inactive and are excreted in the urine and feces. The rate of metabolism may be affected by hepatic function and concurrent drug administration.
Excretion: Flumethasone and its metabolites are excreted primarily in the urine, with a smaller amount in the feces. The elimination half-life varies by species: approximately 1-2 hours in dogs, 2-3 hours in cats, and 1-2 hours in horses and cattle. However, the biological half-life (duration of effect) is longer due to receptor binding and intracellular effects.
Half-Life: Dog: 1-2 hours; Cat: 2-3 hours; Horse: 1-2 hours; Cattle: 1-2 hours
Bioavailability: Oral bioavailability is approximately 60-70% in dogs and cats, but may be lower in ruminants due to ruminal degradation. IM and SC administration provide near-complete bioavailability.
Protein Binding: Approximately 90-95% bound to plasma proteins (CBG and albumin).

Available Formulations & Strengths

Oral Tablet 0.5 mg, 1 mg (PO)
Injectable Solution 0.5 mg/mL, 2 mg/mL (IV/IM/SC)
Topical Cream/Ointment 0.05% (Topical)

Contraindications & Clinical Warnings

Contraindications:
  • Systemic fungal infections
  • Known hypersensitivity to flumethasone or other corticosteroids
  • Viral infections without appropriate antimicrobial coverage
  • Peptic ulcer disease
  • Osteoporosis
  • Pregnancy (especially during early gestation) unless benefits outweigh risks
  • Concurrent use of live vaccines (immunosuppression may impair immune response)
Warnings & Clinical Precautions:
  • Use with caution in animals with diabetes mellitus, renal disease, cardiac disease, hypertension, or epilepsy.
  • Prolonged use may cause HPA axis suppression; taper doses gradually.
  • May exacerbate infections; use with appropriate antimicrobial therapy if infection is present.
  • In horses, corticosteroids have been associated with laminitis; use with caution, especially in animals with a history of laminitis.
  • In cattle, use may cause immunosuppression and increase susceptibility to disease; observe withdrawal times.
  • Use in pregnant animals may cause fetal abnormalities; weigh risks and benefits.
  • Do not administer intra-articularly if infection is suspected.
  • Avoid use in animals with corneal ulcers (topical).

Adverse Effects & Reactions

Common:

  • Increased thirst and urination (polydipsia/polyuria)
  • Increased appetite
  • Panting (in dogs)
  • Gastrointestinal upset (vomiting, diarrhea)
  • Behavioral changes (restlessness, aggression)

Serious / Severe:

  • HPA axis suppression
  • Iatrogenic Cushing's syndrome (with prolonged use)
  • Diabetes mellitus (may precipitate or worsen)
  • Gastrointestinal ulceration and perforation
  • Pancreatitis
  • Laminitis (in horses)
  • Immunosuppression leading to opportunistic infections
  • Delayed wound healing

Rare:

  • Hepatopathy
  • Seizures
  • Anaphylactoid reactions
  • Osteoporosis or pathologic fractures
  • Growth retardation in young animals

Key Drug Interactions

Interacting Drug / Class Clinical Effect & Mechanism Severity
Nonsteroidal anti-inflammatory drugs (NSAIDs) Increased risk of gastrointestinal ulceration and bleeding. High
Insulin or oral hypoglycemic agents Corticosteroids may increase blood glucose, reducing the effectiveness of hypoglycemic agents. Moderate
Diuretics (e.g., furosemide) Increased risk of hypokalemia. Moderate
Amphotericin B Increased risk of hypokalemia and cardiac toxicity. Moderate
Phenobarbital or phenytoin Increased hepatic metabolism of corticosteroids, reducing their efficacy. Mild
Cyclosporine Increased immunosuppressive effects; monitor for toxicity. Moderate
Vaccines (live) Immunosuppression may reduce vaccine efficacy and increase risk of vaccine-induced disease. Moderate

Overdose & Toxicity Management

Signs of Toxicity:

  • Polydipsia, polyuria, polyphagia
  • Gastrointestinal ulceration or hemorrhage
  • Hyperglycemia and glucosuria
  • Electrolyte imbalances (hypokalemia, hypernatremia)
  • Hypertension
  • Immunosuppression
  • Behavioral changes (agitation, depression)
  • In severe cases, seizures or coma

Emergency Treatment Protocol: Treatment is primarily supportive. There is no specific antidote. Induce vomiting if recent oral ingestion and the animal is conscious. Administer activated charcoal to reduce absorption. Monitor vital signs, blood glucose, electrolytes, and renal function. Provide symptomatic care: fluid therapy for dehydration, anti-ulcer medications (e.g., omeprazole, sucralfate) for gastrointestinal protection, and insulin if hyperglycemia is severe. In cases of HPA axis suppression, taper the corticosteroid dose gradually. For anaphylactoid reactions, administer epinephrine and supportive care.

Food Animal Withdrawal Times

🥩 Meat: 8 days🥛 Milk: 3 days

Withdrawal times are based on label recommendations for cattle and may vary by country. For other species, consult local regulations. Not approved for use in poultry or egg-producing animals.

Storage, Handling & Regulatory Information

Storage Temperature: Store at controlled room temperature 20-25°C (68-77°F), with excursions permitted between 15-30°C (59-86°F).

Light Sensitivity: Light-sensitive — protect from direct exposure.

Handling & Special Conditions: Protect from light. Keep container tightly closed. Do not freeze.

Dispensing Status: Prescription Required (Rx Only)

Approval Status: Approved for use in cattle and horses in the United States (e.g., Flucort®). Not approved for use in dogs, cats, or other species, but may be used extra-label.

Extra-Label (Off-Label) Use: In the United States, flumethasone is approved for use in cattle and horses. Extra-label use in other species or at different doses is permitted under AMDUCA (Animal Medicinal Drug Use Clarification Act) provided there is a valid veterinarian-client-patient relationship, and withdrawal times are extended as necessary. Use in food animals must comply with FDA regulations and ensure appropriate withdrawal periods to prevent violative residues.

Clinical Pearls & Practice Notes

💡 Clinical Insights: Flumethasone is a potent corticosteroid used for its anti-inflammatory and immunosuppressive effects. It is more potent than prednisolone and has a longer duration of action. In veterinary practice, it is commonly used for allergic and inflammatory conditions, autoimmune diseases, and as an adjunctive therapy for shock and cerebral edema. Due to its potency, it should be used at the lowest effective dose for the shortest duration possible to minimize adverse effects. Tapering is essential after prolonged use to avoid HPA axis suppression. In food animals, strict adherence to withdrawal times is critical. In horses, caution is advised due to the risk of laminitis. Monitoring for adverse effects such as polyuria, polydipsia, and gastrointestinal signs is recommended. Drug interactions, particularly with NSAIDs, should be considered. Overall, flumethasone is a valuable therapeutic agent when used judiciously.

References & Literature

  • 📚 Plumb's Veterinary Drug Handbook
  • 📚 Papich Veterinary Pharmacology and Therapeutics
  • 📚 Compendium of Veterinary Products (CVP)