Methylprednisolone
Methylprednisolone is an intermediate-acting glucocorticoid; oral tablets, depot acetate and soluble sodium succinate have different administration roles.
Group
Glucocorticoid
Mechanism of Action
Activates intracellular glucocorticoid receptors, changing gene expression to suppress inflammatory and immune responses.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Inflammatory or immune-mediated disease — Initial | 0.25–0.5 mg/kg | PO | Every 12–24 h | Taper to the lowest effective amount and frequency once stable. |
| Inflammatory or immune-mediated disease — Initial | 0.22–0.44 mg/kg | PO | Every 12–24 h | Separate reported label range; taper according to response. |
| Historical emergency steroid treatment | Reference only | IV | Sodium succinate 30 mg/kg initially, followed by 15 mg/kg after 2-6 hours. Benefit in spinal trauma or shock is questionable and gastrointestinal bleeding risk is high; not routine emergency treatment. | |
| Chronic anti-inflammatory maintenance — Maintenance | 0.3–0.5 mg/kg | PO | Every 48 h | |
| Depot anti-inflammatory treatment | 1 mg/kg | IM | Every 168–504 h | Acetate suspension only; reported fixed alternative is 20-40 mg/dog. |
| Depot anti-inflammatory treatment | 20–40 mg/animal | IM | Every 168–504 h | Acetate suspension only; fixed-dose alternative. |
| Broad depot acetate label alternative | Reference only | IM | 2-120 mg/animal, average 20 mg, with repeat at about weekly intervals or according to response. The broad size-dependent label range is not a universal starting amount. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Inflammatory or immune-mediated disease — Initial | 0.25–0.5 mg/kg | PO | Every 12–24 h | Taper to the lowest effective amount and frequency once stable. |
| Inflammatory or immune-mediated disease — Initial | 0.22–0.44 mg/kg | PO | Every 12–24 h | Separate reported label range; taper according to response. |
| Historical emergency steroid treatment | Reference only | IV | Sodium succinate 30 mg/kg initially, followed by 15 mg/kg after 2-6 hours. Benefit in spinal trauma or shock is questionable and gastrointestinal bleeding risk is high; not routine emergency treatment. | |
| Depot anti-inflammatory treatment | 10–20 mg/animal | IM | Every 168–504 h | Acetate suspension only; monitor for diabetes, cardiac decompensation and herpesvirus reactivation. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Depot anti-inflammatory treatment | 200 mg/animal | IM | Once | Acetate formulation. |
Indications
- Inflammatory and immune-mediated disorders
Contraindications
- Use cautiously with diabetes, active infection, gastrointestinal ulceration, impaired wound healing or pregnancy.
Interactions
- NSAIDs increase gastrointestinal ulceration and bleeding.
- May antagonize insulin and impair glycaemic control.
Adverse effects
- Polyphagia, polydipsia and polyuria
- Adrenal suppression, hyperglycaemia, hepatopathy and secondary infection
- Delayed wound healing
Toxicity
Excessive exposure causes iatrogenic hyperadrenocorticism and immunosuppression; abrupt withdrawal after prolonged treatment may cause adrenal insufficiency.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Methylprednisolone 1 mg tablet | Tablet | 1 mg / tablet | PO |
| Methylprednisolone 2 mg tablet | Tablet | 2 mg / tablet | PO |
| Methylprednisolone 4 mg tablet | Tablet | 4 mg / tablet | PO |
| Methylprednisolone 8 mg tablet | Tablet | 8 mg / tablet | PO |
| Methylprednisolone 32 mg tablet | Tablet | 32 mg / tablet | PO |
| Methylprednisolone 20 mg/mL injection Depot acetate salt retained separately; do not use IV. | Injection | 20 mg / mL | IM |
| Methylprednisolone 40 mg/mL injection Depot acetate salt retained separately; do not use IV. | Injection | 40 mg / mL | IM |
| Methylprednisolone sodium succinate 125 mg vial Unreconstituted vial; no final mL concentration is assumed. | Injection | 125 mg / vial | IV, IM |
| Methylprednisolone sodium succinate 500 mg vial Unreconstituted vial; no final mL concentration is assumed. | Injection | 500 mg / vial | IV, IM |
| Methylprednisolone sodium succinate 1000 mg vial Unreconstituted vial; no final mL concentration is assumed. | Injection | 1000 mg / vial | IV, IM |
| Methylprednisolone sodium succinate 2000 mg vial Unreconstituted vial; no final mL concentration is assumed. | Injection | 2000 mg / vial | IV, IM |
| Methylprednisolone 16 mg tablet | Tablet | 16 mg / tablet | PO |
| Methylprednisolone 24 mg tablet | Tablet | 24 mg / tablet | PO |
| Methylprednisolone acetate 80 mg/mL suspension Depot suspension; not for IV use. | Injection | 80 mg / mL | IM |
Monitoring and Administration
Monitor glucose, hepatic and renal parameters, infection and adrenal function when indicated.
Taper sustained systemic treatment according to response rather than stopping abruptly; depot injections cannot be withdrawn after administration.
Equine intra-articular acetate: 40-240 mg per joint, average 120 mg, using aseptic technique. Use an appropriate joint formulation and aseptic technique.
Sodium succinate reconstitution and use periods are product-specific; the published guidance describes up to 48 hours at room temperature. Acetate suspension must not be injected IV.
Monitor cats for diabetes, volume expansion or congestive heart failure after depot injection; injection-site alopecia and latent herpesvirus reactivation are reported.
Canine adrenal-replacement amount is 0.2 mg/kg/day, but route is missing in that entry; the dose is retained without an inferred route.
Approximate systemic potency conversion from prednisone/prednisolone is to divide its milligram amount by 1.25 for methylprednisolone; this does not convert depot kinetics or route. Label weight-group oral totals are dogs 5-15 lb: 2 mg/day, 15-40 lb: 2-4 mg/day, 40-80 lb: 4-8 mg/day; cats 5-15 lb: 2 mg/day and over 15 lb: 2-4 mg/day. These daily totals are divided 6-10 hours apart and must not be repeated whole at every interval.
Local intralesional acetate treatment uses 10-40 mg total of 20 mg/mL suspension to undermine the lesion; a dedicated local-procedure route is required. Equine intra-articular alternative is 100 mg/joint. Do not inject local steroid into an infected site. High-dose treatment for hypovolaemic/haemorrhagic shock, head or spinal trauma and sepsis lacks supporting evidence.