Methylprednisolone

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Contents 1 Introduction 2 Indications 3 Dosage 4 Pharmacokinetics 5 Adverse-effects 6 Drug-interactions 7 Mechanism-of-action 8 More General Terms 9 Additional Terms 10 Internet Database 11 References

Introduction

• Systemic agent: Tradenames: Medrol, Solu-Medrol, Depo-Medrol. (6-alpha-methylprednisolone)

Indications

• anti-inflammatory agent
• immunosuppressive agent

Dosage

• 10-125 mg IV/ IM* every 6 hours
• 4-48 mg PO QD
• spinal cord injury:

• 30 mg/kg IV bolus followed by 5.4 mg/kg/h infusion

• intra-articular:

• large joints: 20-80 mg
• small joints: 4-10 mg

• intra-lesional: 20-60 mg

• Tabs: 2, 4, 8, 16, 24, 32 mg. Medrol Dosepack: tapers 24 to 0 mg over 7 days. Injection (as acetate): 40 mg/mL (1 mL); 80 mg/mL (1 mL) Injection (as succinate): 40 mg, 125 mg, 500 mg, 1000 mg
• * Depo-Medrol: low solubility, sustained action IM (8 days).
• Equivalent dose: -methylprednisolone 4 mg = hydrocortisone 20 mg

Pharmacokinetics

• does not require hepatic activation for activity
• oral:

• peak effect in 1-2 hours
• duration of action: 30-36 hours

• intramuscular ( IM):

• peak effect in 4-8 days
• duration of action: 1-4 weeks

• intra-articular

• peak effect in 1 week
• duration of action: 1-5 weeks

• volume of distribution is 0.7-1.5 L/kg
• metabolized in the liver by cyt P450 3A4
• elimination 1/2life is 3-3.5 hours, with slower clearance in the elderly
  

• elimination via liver
• 1/2life = 3-3.5 hours

Adverse-effects

• common (> 10%)

• increased appetite, insomnia, indigestion, nervousness

• less common (1-10%)

• cataracts, diabetes mellitus, hirsuitism, joint pain, epistaxis

• uncommon (< 1%)

• seizures, mood swings, headache, skin atrophy, bruising, hyperpigmentation, acne, amenorrhea, Na+ & H2O retention, Cushing's syndrome, hyperglycemia, suppression of bone growth, abdominal distention, ulcerative esophagitis, pancreatitis, muscle wasting, hypersensitivity, delirium, hallucinations, euphoria

• short-term effects

• fluid & electrolyte disturbances
• hyperglycemia
• poor wound healing
• GI disturbances
• spread of infection

• long-term use

• osteoporosis
• bone fractures
• pituitary & adrenal insufficiency
• Cushing's syndrome
• too rapid withdrawal can result in acute adrenal insufficiency
  
• drug adverse effects of glucocorticoids
• drug adverse effects of immunosuppressive agents

Drug-interactions

• aminoglutethimide
• anticholinesterases
• barbiturates
• carbamazepine
• phenytoin
• rifampin
• live virus vaccines
• any drug that inhibits cyt P450 3A4 may increase levels of methylprednisolone
• any drug that induces cyt P450 3A4 may diminish levels of methylprednisolone
  
• drug interaction(s) of glucocorticoids with warfarin

Mechanism-of-action

• immediately-acting glucocorticoid
• does not require hepatic activation for activity

More General Terms

• glucocorticoid
• neurologic agent

Additional Terms

• cytochrome P450 3A4 (cytochrome P450 C3, nifedipine oxidase, P450-PCN1, NF-25, CYP3A4)
• prednisolone; deltahydrocortisone; metacortandralone (Pred Forte, AK-Pred, Inflamase, Pediapred, Pred Mild, Prelone, Flo-Pred, Veripred 20)

Internet Database

PubChem: 6741
PubChem: 5877
PubChem: 16922
PubChem: 584547
PubChem: 4159
PubChem: 657303
PubChem: 1875

References

1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
3. Kaiser Permanente Northern California Regional Drug Formulary, 1998
4. Prescriber's Letter 13(3): 2006 Cytochrome P450 drug interactions Detail-Document#: [1] (subscription needed) [2]
5. Geriatric Dosage Handbook, 6th edition, Selma et al eds, Lexi-Comp, Cleveland, 2001

methylprednisolone (Medrol, Solu-Medrol, Depo-Medrol)