Methylprednisolone
6alpha-methylprednisolone
Also known as: Depo-Medrol · Solu-Medrol · A-Methapred · Depo-Medrone · Solu-Medrone · 6alpha-methylprednisolone · methylprednisolonum · NSC-19987 · Methylprednisolone acetate · Methylprednisolone sodium succinate
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Labeled uses (Oral) | Dogs weighing 5-15 lbs: 2 mg; Dogs weighing 15-40 lbs: 2-4 mg; Dogs weighing 40-80 lbs: 4-8 mg; these total daily doses should be divided | PO | q6-10h | — | 🌎 NA |
| Labeled uses (Injectable) | 2-120 mg (average 20 mg) | IM | May repeat at weekly intervals | — | 🌎 NA |
| Intralesional (sub-lesional) use | 10-40 mg total dose | intralesional | — | — | 🌎 NA |
- Labeled uses (Oral): Divide total daily dose and give 6-10 hours apart.
- Labeled uses (Injectable): Depending on breed (size), severity of condition, and response.
- Intralesional (sub-lesional) use: A sufficient volume of 20 mg/mL methylprednisolone acetate is used to undermine the lesion.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Labeled uses (Oral) | Cats weighing 5-15 lbs: 2 mg; Cats weighing >15 lbs: 2-4 mg; these total daily doses should be divided | PO | q6-10h | — | 🌎 NA |
| Labeled uses (Injectable) | up to 20 mg (average 10 mg) | IM | May repeat at weekly intervals | — | 🌎 NA |
| Intralesional (sub-lesional) use | 10-40 mg total dose | intralesional | — | — | 🌎 NA |
- Labeled uses (Oral): Divide total daily dose and give 6-10 hours apart.
- Labeled uses (Injectable): Depending on breed (size), severity of condition, and response.
- Intralesional (sub-lesional) use: A sufficient volume of 20 mg/mL methylprednisolone acetate is used to undermine the lesion.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Antiinflammatory (glucocorticoid effects) | 200 mg | IM | repeated as necessary | — | 🌎 NA |
| Intra-articular use | 100 mg | IA | — | — | 🌎 NA |
- Antiinflammatory (glucocorticoid effects): Labeled use.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Methylprednisolone is a synthetic, intermediate-acting glucocorticoid that is approximately 4 to 5 times more potent than hydrocortisone and possesses negligible mineralocorticoid activity. It is utilized extensively in veterinary medicine for its potent anti-inflammatory and immunosuppressive properties.
Clinical Pearls & Formulations:
- Methylprednisolone base: Used in oral tablet formulations for maintenance or tapering therapy.
- Methylprednisolone acetate (Depo-Medrol®): A microcrystalline suspension for IM, intralesional, or intra-articular injection. It is slowly absorbed, providing a prolonged repository effect (weeks to months). Note: It can cause profound and prolonged Hypothalamic-Pituitary-Adrenal (HPA) axis suppression.
- Methylprednisolone sodium succinate (Solu-Medrol®): A highly water-soluble ester designed for rapid IV administration in acute crises (e.g., spinal cord trauma, severe allergic reactions, shock), though high-dose use in shock/trauma is increasingly controversial.
While highly effective, the goal of glucocorticoid therapy is always to use the lowest effective dose for the shortest possible duration to minimize systemic adverse effects, particularly iatrogenic hyperadrenocorticism (Cushing's syndrome).
Mechanism of action
Glucocorticoids exert their effects by diffusing across cell membranes and binding to specific cytoplasmic glucocorticoid receptors (GR).
- Genomic Pathway: The receptor-ligand complex translocates to the nucleus → binds to glucocorticoid response elements (GREs) on target genes → alters gene transcription.
- Anti-inflammatory Mechanism: They induce the synthesis of lipocortin-1 (annexin-1) → inhibits phospholipase A2 → blocks the release of arachidonic acid from membrane phospholipids → profoundly decreases the synthesis of pro-inflammatory prostaglandins and leukotrienes.
- Immunosuppressive Mechanism: They suppress the transcription of inflammatory cytokines (e.g., IL-1, IL-2, IL-6, TNF-alpha), inhibit macrophage and neutrophil migration/function, and induce apoptosis in lymphocytes.
- Metabolic Effects: Stimulate hepatic gluconeogenesis, promote protein catabolism, and redistribute lipid stores.
Safety & warnings
Contraindications
- Systemic fungal infections (unless used for Addison's replacement)
- Viral infections
- Arrested tuberculosis
- Peptic or corneal ulcers
- Acute psychoses
- Cushingoid syndrome
- Idiopathic thrombocytopenia (for IM administration)
- Acute local infections (for intrasynovial/intratendinous use)
- Chronic systemic therapy using sustained-release injectable forms
- Pregnant animals
- Renal disease
- Diabetes mellitus
Adverse effects
- Polyuria (PU), polydipsia (PD), polyphagia (PP)
- Iatrogenic hyperadrenocorticism (Cushingoid signs) with sustained use
- Weight gain and lipidemias
- Dull, dry haircoat and alopecia
- Muscle wasting and weakness
- Gastrointestinal ulceration, vomiting, diarrhea, melena, hematochezia
- Elevated liver enzymes (ALP, ALT) and hepatopathy
- Pancreatitis
- Activation or worsening of diabetes mellitus (especially in cats)
- Behavioral changes (depression, lethargy, viciousness, panting)
- Extracellular hyperglycemia leading to volume expansion and potential CHF (cats)
- Hypothalamic-pituitary-adrenal (HPA) axis suppression
- Adrenal atrophy
- Weight loss (catabolic effect)
- Cutaneous atrophy (thinning of skin)
- Iatrogenic hyperadrenocorticism (Cushing's syndrome)
- Diarrhoea
- Increased urine glucose levels
- Decreased serum T3 and T4 levels
- Impaired wound healing
- Delayed recovery from infections
Precautions
Tapering Required: Animals receiving systemic glucocorticoids (other than short 'burst' therapy) must be tapered off slowly to allow endogenous ACTH and corticosteroid function to recover. Abrupt withdrawal can precipitate an Addisonian crisis.
- Stress Dosing: Additional glucocorticoids may be needed during stressors (surgery, trauma, illness) during the tapering process.
- Use with Caution: In patients with diabetes mellitus, osteoporosis, predisposition to thrombophlebitis, hypertension, congestive heart failure (CHF), and renal insufficiency.
- Pregnancy: FDA Category C. May cause teratogenic effects in early pregnancy. Exogenous steroids can induce parturition in the latter stages of pregnancy in horses and ruminants.
- Nursing Dams: Glucocorticoids enter milk and may inhibit growth or interfere with endogenous corticosteroid production in nursing offspring.
Drug interactions
May cause hypokalemia; potential for CHF and cardiac enlargement
Combination in epidurals has caused serious CNS injuries and death
May lead to profound muscle weakness in myasthenia gravis patients
Glucocorticoids may reduce salicylate blood levels
May increase the metabolism of glucocorticoids and decrease blood levels
Glucocorticoids may inhibit hepatic metabolism of cyclophosphamide
May mutually inhibit hepatic metabolism, increasing blood levels of both drugs
May cause hypokalemia
May reduce methylprednisolone blood levels
May potentiate the effects of methylprednisolone
Insulin requirements may increase due to glucocorticoid-induced insulin resistance
May decrease metabolism of glucocorticoids; ketoconazole may induce adrenal insufficiency upon withdrawal
May decrease metabolism of glucocorticoids and increase blood levels
May alter steroid metabolism; higher steroid doses may be needed
Increased risk of severe gastrointestinal ulceration
May increase metabolism of glucocorticoids and decrease blood levels
May increase metabolism of glucocorticoids and decrease blood levels
Virus replication may be augmented; diminished immune response to vaccines
May affect INR values; requires monitoring
Increased risk of hypokalaemia
Enhanced metabolism of corticosteroids, potentially reducing their efficacy
Decreased metabolism of corticosteroids, potentially increasing their effects and toxicity
Monitoring
- Weight, appetite, and signs of edema
- Serum and/or urine electrolytes
- Total plasma proteins, albumin
- Growth and development in young animals
- ACTH stimulation test (if iatrogenic Cushing's or Addison's is suspected)
- Clinical signs of iatrogenic hyperadrenocorticism (PU/PD, polyphagia, weight gain)
- Blood glucose levels (especially in diabetic or pre-diabetic patients)
- Serum electrolytes (specifically potassium)
- Thyroid panel (T3 and T4 may be artificially decreased)
- Signs of gastrointestinal ulceration (melena, vomiting blood)
Pharmacokinetics
Half-life
Absorption
Orally administered methylprednisolone is relatively well absorbed. The acetate IM injection is slowly absorbed and can have a duration of effect of weeks to months. The sodium succinate IV injection is water soluble and very fast acting.
Distribution
Extensively distributed throughout the body.
Metabolism
The liver is the primary site for metabolism (oxidation).
Elimination
Most of the drug is excreted renally as metabolites.
Overdose
Short-term administration of massive doses is unlikely to cause harmful effects, though one case of acute CNS effects in a dog after accidental ingestion has been reported. If acute overdose occurs, provide supportive treatment as required.
Chronic Overdosage: Chronic usage leads to serious adverse effects, primarily iatrogenic hyperadrenocorticism (Cushing's syndrome), characterized by profound metabolic, dermatologic, and immunosuppressive changes.
Available products
Formulations
- Injectable suspension (Acetate)
- Powder for injection (Sodium Succinate)
- Injectable depot suspension: 40 mg/ml
- Injectable powder for reconstitution: 125 mg, 500 mg
- Oral tablets: 2 mg, 4 mg
Veterinary
- Methylprednisolone Tablets: 4 mg (Medrol®)
- Methylprednisolone Acetate Injection: 20 mg/mL, 40 mg/mL (Depo-Medrol®)
- Depo-Medrone 40 mg/ml depot suspension
- Solu-Medrone 125 mg powder for reconstitution
- Solu-Medrone 500 mg powder for reconstitution
- Medrone 2 mg tablets
- Medrone 4 mg tablets
Human-labeled
- Methylprednisolone Oral Tablets: 2 mg, 4 mg, 8 mg, 16 mg, 24 mg, 32 mg (Medrol®)
- Methylprednisolone Acetate Injection: 20 mg/mL, 40 mg/mL, 80 mg/mL (Depo-Medrol®)
- Methylprednisolone Sodium Succinate Powder for Injection: 40 mg, 125 mg, 500 mg, 1 gram, 2 grams per vial (Solu-Medrol®, A-Methapred®)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store commercially available products at room temperature (15-30°C). Avoid freezing the acetate injection. After reconstituting the sodium succinate injection, store at room temperature and use within 48 hours; only use solutions that are clear.
Client information
Important Guidelines for Pet Owners:
- Do Not Stop Abruptly: Never discontinue this medication suddenly without consulting your veterinarian. The body's natural steroid production goes to sleep while on this drug, and stopping abruptly can cause a life-threatening crisis. Your vet will provide a tapering schedule.
- Expected Side Effects: It is very common for pets to drink more water, urinate more frequently, and have an increased appetite while on this medication. Ensure they always have access to fresh water and frequent bathroom breaks.
- Watch for Severe Signs: Contact your veterinarian if you notice severe side effects such as vomiting, dark/tarry stools, bloody diarrhea, extreme lethargy, panting, or significant behavioral changes.
- Follow Instructions: Give the medication exactly as prescribed. If using an alternate-day schedule, it may be helpful to mark a calendar to avoid missing doses.
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.