How to order Meropenem 0.5 g IV q12 hrs to start now?

Meropenem 0.5 g IV q12h Order

For an adult patient, order Meropenem 500 mg IV every 12 hours, administered as an intravenous infusion over 15-30 minutes, starting immediately. 1

Standard Order Components

• Drug name and dose: Meropenem 500 mg (0.5 g) 1
• Route: Intravenous (IV) 1
• Frequency: Every 12 hours (q12h) 1
• Administration method: Infuse over 15-30 minutes 1
• Start time: Now (immediate start) 1

Important Clinical Context

Note that the q12h dosing interval you've specified is NOT the standard FDA-approved regimen for most indications. The FDA-approved dosing for meropenem is typically every 8 hours, not every 12 hours. 1

Standard FDA-Approved Dosing

• Complicated skin and skin structure infections: 500 mg IV every 8 hours 1
• Intra-abdominal infections: 1 gram IV every 8 hours 1
• When treating Pseudomonas aeruginosa: 1 gram IV every 8 hours (regardless of infection type) 1

When q12h Dosing IS Appropriate

The every 12 hours interval is only FDA-approved for adult patients with renal impairment who have a creatinine clearance of 26-50 mL/min—in these patients, give the recommended dose (500 mg for cSSSI or 1 gram for intra-abdominal infections) every 12 hours instead of every 8 hours. 1

Critical Ordering Considerations

• Verify renal function: If the patient has normal renal function (CrCl >50 mL/min), the standard dosing should be every 8 hours, not every 12 hours 1
• If CrCl 26-50 mL/min: The q12h interval is appropriate with the full recommended dose 1
• If CrCl 10-25 mL/min: Give one-half the recommended dose every 12 hours 1
• If CrCl <10 mL/min: Give one-half the recommended dose every 24 hours 1

Alternative Administration Methods

• IV bolus injection: Can be given as 5-20 mL bolus over 3-5 minutes if preferred over infusion 1
• Extended infusion: For critically ill patients or resistant organisms with MIC ≥8 mg/L, consider 3-hour extended infusion to optimize pharmacodynamics 2

Common Pitfalls to Avoid

• Underdosing for Pseudomonas: If treating suspected or confirmed P. aeruginosa infection, 500 mg is insufficient—increase to 1 gram every 8 hours 1
• Incorrect frequency in normal renal function: The q12h interval is only appropriate for moderate renal impairment, not normal kidney function 1
• Inadequate infusion time: Ensure the 15-30 minute infusion time is specified to avoid administration errors 1