Betamethasone
Also known as: Gentocin Durafilm (historical) · Isaderm · Osurnia · Otomax · Betnesol · Maxidex · Betametasona · Betamethasonum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Dosing by species
Dosing data for this drug is not yet available in the VetSheet formulary. Every other section below is complete. Consult the current product label before prescribing.
Overview
Betamethasone is a potent, long-acting glucocorticoid used in veterinary medicine primarily for its profound anti-inflammatory and immunosuppressive effects.
In ophthalmic applications, it was formerly available as a veterinary-approved antimicrobial-steroid combination (Gentocin Durafilm®). While commercial veterinary ophthalmic products containing betamethasone are currently discontinued, compounding pharmacists can still provide preparations combining gentamicin and betamethasone for specific clinical needs.
Mechanism of action
Betamethasone diffuses across cell membranes and binds to specific cytosolic glucocorticoid receptors. The receptor-ligand complex translocates to the nucleus, where it alters gene expression (transactivation and transrepression).
→ Inhibits phospholipase A2 (via lipocortin induction), blocking the release of arachidonic acid. → Decreases production of inflammatory mediators (prostaglandins, leukotrienes, cytokines). → Suppresses immune system response by reducing leukocyte migration and capillary permeability.
Safety & warnings
Contraindications
- Suspected corneal abrasion
- Corneal ulceration
- Feline herpes keratitis (FHV-1)
Adverse effects
- Delayed corneal healing
- Increased intraocular pressure (IOP)
- Potentiation of ocular infections
- Systemic absorption leading to adrenal suppression (rare with topical use but possible in small patients)
Precautions
Warning: This preparation should never be utilized if corneal abrasion or ulceration are suspected. It is strictly contraindicated in cats with suspected or confirmed herpes keratitis due to the risk of severe exacerbation and corneal melting.
Drug interactions
Increased risk of GI ulceration
Glucocorticoids antagonize the effect of insulin
May accelerate the metabolism of corticosteroids
May decrease the metabolism of corticosteroids
Increased risk of hypokalaemia
Increased risk of hypokalaemia
Increased risk of hypokalaemia
Increased risk of hypokalaemia
Monitoring
- Fluorescein staining (to ensure intact cornea prior to and during use)
- Intraocular pressure (IOP)
- Resolution of clinical signs of inflammation
Pharmacokinetics
Absorption
Topical ophthalmic corticosteroids can be absorbed systemically, particularly if the corneal epithelium is compromised or if applied frequently.
Distribution
Distributes locally into the cornea, aqueous humor, and anterior uvea.
Metabolism
Hepatic metabolism if systemically absorbed.
Elimination
Excreted primarily via the kidneys.
Overdose
Overdose via topical ophthalmic administration is unlikely to cause acute life-threatening signs, but chronic overuse can lead to iatrogenic hyperadrenocorticism (Cushing's syndrome) and local ocular complications (glaucoma, corneal degeneration).
Available products
Formulations
- Ophthalmic drops (compounded)
Regulatory status
POM-V, POM
POM-V, POM
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store compounded preparations according to the dispensing pharmacy's instructions, typically at room temperature away from light and moisture.
Client information
Administration: Apply exactly as directed by your veterinarian. Wash your hands before and after applying the medication. Do not touch the dropper tip to the eye or any other surface.
Safety: Never use this medication without a veterinarian's explicit instruction, especially if your pet is squinting or has a red eye, as it can cause severe damage or loss of the eye if a corneal scratch or ulcer is present.
Monitoring: Contact your veterinarian immediately if your pet's eye becomes cloudier, more painful, or if discharge increases.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.