Adults

Dosage varies widely based on condition. For acute severe conditions (e.g., spinal cord injury, organ transplant rejection), 250 mg to 1000 mg IV daily or every 6 hours for a short period (e.g., 3-5 days). Lower doses may be used for other conditions.

Elderly

No specific dosage adjustment solely based on age; however, caution is advised due to increased risk of side effects and comorbidities. Dosage typically follows adult guidelines.

Renal_impairment

No dosage adjustment is generally required for renal impairment, as corticosteroids are primarily metabolized by the liver.

Onset

Rapid, within minutes for IV effects.

Excretion

Excreted predominantly in the urine as inactive metabolites.

Half life

Plasma half-life is approximately 2-3 hours; biological half-life is 18-36 hours.

Absorption

Rapidly absorbed after intravenous administration. Bioavailability is complete with IV.

Metabolism

Primarily hepatic, mainly by CYP3A4.

NSAIDs (e.g., Ibuprofen)

Increased risk of gastrointestinal ulceration and bleeding.

Diuretics (e.g., Furosemide)

May enhance potassium depletion.

Anticoagulants (e.g., Warfarin)

Corticosteroids may potentiate or inhibit the effect of anticoagulants; close monitoring of INR is required.

CYP3A4 inducers (e.g., Phenobarbital, Rifampicin)

May decrease methylprednisolone levels, reducing its efficacy.

CYP3A4 inhibitors (e.g., Ketoconazole, Ritonavir)

May increase methylprednisolone levels, leading to increased effects and side effects.