I.M./I.V. daily in divided doses every 4 to 6 hours (have been administered intravenously over 10 to 15 minutes for serious infections). Or as prescribed by the physician.
Directions for Reconstitution: Use only freshly prepared solutions. Intramuscular and intravenous injections should be administered within one hour after preparation since the potency may decrease significantly after this period.
For Intramuscular Use: Dissolve contents of a vial with the amount of Sterile Water for Injection, USP, or Bacteriostatic Water for Injection, USP, listed in the table as follows: See table.
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While Ampicillin for Injection, USP, 1 g and 2 g, are primarily for intravenous use, they may be administered intramuscularly when the 250 mg or 500 mg vials are unavailable. In such instances, dissolve in 3.5 or 6.8 mL Sterile Water for Injection, USP, or Bacteriostatic Water for Injection, USP, respectively. The resulting solution will provide a concentration of 250 mg per mL.
For Direct Intravenous Use: Add 5 mL Sterile Water for Injection, USP, or Bacteriostatic Water for Injection, USP to the 125, 250, and 500 mg vials and administer slowly over a 3- to 5- minute period. Ampicillin for Injection, USP, 1 g or 2 g, may also be given by direct Intravenous administration. Dissolve in 7.4 or 14.8 mL Sterile Water for Injection, USP, or Bacteriostatic Water for Injection, USP, respectively, and administer slowly over at least 10 to 15 minutes. CAUTION: More rapid administration may result in convulsive seizures.
For Administration by Intravenous Drip: Reconstitute as previously directed (For Direct Intravenous Use) prior to diluting with Intravenous Solution. Stability studies on ampicillin sodium at several concentrations in various intravenous solutions indicate the drug will lose less than 10% activity at the temperatures noted for the time periods stated. Discard any remaining portion after use.