What antibiotics cover both Gram-negative and Gram-positive bacteria?

From the Guidelines

Broad-spectrum antibiotics that cover both Gram-positive and Gram-negative bacteria include carbapenems, such as meropenem 1g 8-hourly or imipenem/cilastatin 500mg 6-hourly, as well as piperacillin/tazobactam 4.5g 6-hourly, as recommended in the most recent guidelines 1.

Key Considerations

• The choice of empiric antibiotic regimens should be based on the clinical condition of the patients, the individual risk for infection by resistant pathogens, and the local resistance epidemiology 1.
• Carbapenems are often considered the broadest spectrum and are typically reserved for serious infections to prevent resistance.
• Dosing varies by specific drug and patient factors such as kidney function, weight, and infection severity.

Antibiotic Options

• Meropenem is typically dosed at 1g IV every 8 hours.
• Imipenem/cilastatin is typically dosed at 500mg IV every 6 hours.
• Piperacillin/tazobactam is typically dosed at 4.5g IV every 6 hours.

Important Notes

• When prescribing broad-spectrum antibiotics, it's essential to narrow therapy based on culture results when available to prevent antimicrobial resistance.
• These medications also have different side effect profiles and contraindications that should be considered when selecting therapy for a specific patient.
• The use of carbapenems should be limited to preserve the activity of this class of antibiotics due to the concern of emerging carbapenem-resistance 1.

From the FDA Drug Label

Levofloxacin has in vitro activity against Gram-negative and Gram-positive bacteria Aerobic bacteria Gram-Positive Bacteria Enterococcus faecalis Staphylococcus aureus (methicillin-susceptible isolates) Staphylococcus epidermidis (methicillin-susceptible isolates) Staphylococcus saprophyticus Streptococcus pneumoniae (including multi-drug resistant isolates [MDRSP]1) Streptococcus pyogenes Gram-Negative Bacteria Enterobacter cloacae Escherichia coli Haemophilus influenzae Haemophilus parainfluenzae Klebsiella pneumoniae Legionella pneumophila Moraxella catarrhalis Proteus mirabilis Pseudomonas aeruginosa Serratia marcescens

• Levofloxacin covers both Gram-negative and Gram-positive bacteria, including:

• Gram-positive bacteria: Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis
• Gram-negative bacteria: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa

2

From the Research

Antibiotics Effective Against Both Gram-Negative and Gram-Positive Bacteria

• Imipenem/cilastatin is a carbapenem antibiotic that has a broad spectrum of activity against Gram-positive, Gram-negative, and anaerobic organisms 3.
• Meropenem is another carbapenem antibiotic that has a broad spectrum of activity against Gram-positive and Gram-negative pathogens, including extended-spectrum beta-lactamase (ESBL)- and AmpC-producing Enterobacteriaceae 4.
• The carbapenem class of antibiotics, which includes imipenem, meropenem, doripenem, and ertapenem, has an exceptionally broad spectrum of activity against Gram-positive, Gram-negative, and anaerobic bacteria 5.
• Imipenem-cilastatin sodium is a broad-spectrum carbapenem antibiotic combination that is effective against Gram-positive and Gram-negative aerobic and anaerobic organisms 6.
• Meropenem has a wide spectrum of activity against Gram-positive and Gram-negative bacteria, and its pharmacokinetics are characterized by a peak plasma concentration of approximately 30 mg/L after administration of a standard dose of 1 g intravenously 7.

Key Characteristics of These Antibiotics

• Imipenem/cilastatin and meropenem have been shown to be effective in the treatment of a variety of infections, including complicated intra-abdominal infections, skin and skin structure infections, community-acquired pneumonia, nosocomial pneumonia, complicated urinary tract infections, meningitis, and febrile neutropenia 3, 4, 5, 6.
• The carbapenem antibiotics are stable to most beta-lactamases, including AmpC beta-lactamases and extended-spectrum beta-lactamases 5.
• Resistance to carbapenems can develop through various mechanisms, including changes in penicillin-binding proteins, acquisition of metallo-beta-lactamases, and changes in membrane permeability 5.
• The pharmacokinetics of meropenem are characterized by a short elimination half-life of approximately 1 hour, and the drug is eliminated both by metabolism and excretion 7.