A-Methapred (Methylprednisolone Sodium Succinate) - Description and Clinical Pharmacology

R_x only

For Intravenous or Intramuscular Administration

DESCRIPTION

A-Methapred (methylprednisolone sodium succinate for injection, USP) sterile powder contains methylprednisolone sodium succinate as the active ingredient. Methylprednisolone sodium succinate, USP, occurs as a white, or nearly white, odorless hygroscopic, amorphous solid. It is very soluble in water and in alcohol; it is insoluble in chloroform and is very slightly soluble in acetone.

  The chemical name for methylprednisolone sodium succinate is pregna-1,4-diene-3,20-dione,21-(3-carboxy-1-oxo-propoxy)-11,17-dihydroxy-6-methyl-monosodium salt, (6α, 11β), and the molecular weight is 496.53.

   The structural formula is represented below:

   Methylprednisolone sodium succinate is so extremely soluble in water that it may be administered in a small volume of diluent and is especially well suited for intravenous use in situations in which high blood levels of methylprednisolone are required rapidly.

  A-Methapred is available in several strengths and packages for intravenous or intramuscular administration.

40 mg Single-Dose Vial − Each mL (when mixed) contains methylprednisolone sodium succinate equivalent to 40 mg methylprednisolone; also 1.6 mg monobasic sodium phosphate anhydrous; 17.46 mg dibasic sodium phosphate anhydrous; 25 mg lactose anhydrous; 8.8 mg benzyl alcohol added as preservative.

125 mg Single-Dose Vial − Each 2 mL (when mixed) contains methylprednisolone sodium succinate equivalent to 125 mg methylprednisolone; also 1.6 mg monobasic sodium phosphate anhydrous; 17.4 mg dibasic sodium phosphate anhydrous; 17.6 mg benzyl alcohol added as preservative.

   When necessary, the pH of each formula was adjusted with sodium hydroxide so that the pH of the reconstituted solution is within the USP specified range of 7 to 8 and the tonicities are, for the 40 mg per mL solution, 0.50 osmolar; for the 125 mg per 2 mL, 0.40 osmolar; (Isotonic saline = 0.28 osmolar).

IMPORTANT − Use only Bacteriostatic Water For Injection with Benzyl Alcohol when reconstituting A-Methapred.

Use within 48 hours after mixing.

CLINICAL PHARMACOLOGY

Methylprednisolone is a potent anti-inflammatory steroid with greater anti-inflammatory potency than prednisolone and even less tendency than prednisolone to induce sodium and water retention.

   Methylprednisolone sodium succinate has the same metabolic and anti-inflammatory actions as methylprednisolone. When given parenterally and in equimolar quantities, the two compounds are equivalent in biologic activity. The relative potency of A-Methapred sterile powder and hydrocortisone sodium succinate, as indicated by depression of eosinophil count, following intravenous administration, is at least four to one. This is in good agreement with the relative oral potency of methylprednisolone and hydrocortisone.