Antibiotic spectrum index
From IDWiki
- Measures the spectrum of an antibiotic, with a range from 0 to 14
- One point for activity against each of the following:
- Methicillin-sensitive Staphylococcus aureus (MSSA)
- Methicillin-resistant Staphylococcus aureus (MRSA)
- Enterococcus faecalis
- Vancomycin-resistant Enterococcus faecalis (VRE)
- Escherichia coli or Klebsiella
- AmpC producers (Enterobacter, Serratia, and Citrobacter)
- Extended-spectrum β-lactamase (ESBL) E. coli/Klebsiella
- Pseudomonas aeruginosa
- Penicillin-resistant pneumococcus (PRP)
- Moraxella and Haemophilus influenzae
- Mycoplasma and Chlamydophila (atypicals)
- Anaerobes (in general)
- Bacteriodes fragilis (specifically)
- Multidrug-resistant organisms
- For each patient, the number of points for every antibiotic is added to give a total daily ASI
Working Ranking
- The following is a reasonable list of commonly-used antibiotics, order from broadest to narrowest, not based on the ASI
- Cefiderocol, Colistin, Polymyxin B, Meropenem-vaborbactam, Imipenem-relebactam, Ceftazidime-avibactam, Ceftolozane-tazobactam, Tigecycline, Meropenem, Doripenem, Ertapenem, Piperacillin-tazobactam, Ticarcillin-clavulanate, Fosfomycin, Moxifloxacin, Levofloxacin, Ciprofloxacin, Doxycycline, Amikacin, Tobramycin, Gentamicin, Cefipime, Ceftazidime, Trimethoprim-sulfamethoxazole, Ampicillin-sulbactam, Amoxicillin-clavulanate, Ceftaroline, Ceftriaxone, Cefuroxime, Cefazolin, Ampicillin, Amoxicillin
Sample Spectrum Index
| Antibiotic | MSSA | E.faeca | Anaer | Bact | M/H.flu | E/K | AmpC | ESBL | Pseudo | MRSA | PRP | VRE | Atyp | MDRO | ASI |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dicloxacillin | + | – | – | – | – | – | – | – | – | – | – | – | – | – | 1 |
| Oxacillin | + | – | – | – | – | – | – | – | – | – | – | – | – | – | 1 |
| Amoxicillin | – | + | – | – | – | + | – | – | – | – | – | – | – | – | 2 |
| Ampicillin | – | + | – | – | – | + | – | – | – | – | – | – | – | – | 2 |
| Cephalexin | + | – | – | – | – | + | – | – | – | – | – | – | – | – | 2 |
| Erythromycin | – | – | – | – | + | – | – | – | – | – | – | – | + | – | 2 |
| Erythromycin | – | – | – | – | + | – | – | – | – | – | – | – | + | – | 2 |
| Metronidazole | – | – | + | + | – | – | – | – | – | – | – | – | – | – | 2 |
| Penicillin | – | + | + | – | – | – | – | – | – | – | – | – | – | – | 2 |
| Aztreonam | – | – | – | – | + | + | – | – | + | – | – | – | – | – | 3 |
| Cefazolin | + | – | – | – | + | + | – | – | – | – | – | – | – | – | 3 |
| Cefdinir | + | – | – | – | + | + | – | – | – | – | – | – | – | – | 3 |
| Cefixime | – | – | + | – | + | + | – | – | – | – | – | – | – | – | 3 |
| Cefpodoxime | + | – | – | – | + | + | – | – | – | – | – | – | – | – | 3 |
| Rifampin | + | – | – | – | + | – | – | – | – | + | – | – | – | – | 3 |
| Azithromycin | + | – | + | – | + | – | – | – | – | – | – | – | + | – | 4 |
| Cefprozil | + | – | + | – | + | + | – | – | – | – | – | – | – | – | 4 |
| Ceftazidime | – | – | + | – | + | + | – | – | + | – | – | – | – | – | 4 |
| Cefuroxime | + | – | + | – | + | + | – | – | – | – | – | – | – | – | 4 |
| Chloramphenicol | – | – | + | + | + | + | – | – | – | – | – | – | – | – | 4 |
| Clarithromycin | + | – | + | – | + | – | – | – | – | – | – | – | + | – | 4 |
| Clindamycin | + | – | + | + | – | – | – | – | – | + | – | – | – | – | 4 |
| Piperacillin | – | + | + | – | – | + | – | – | + | – | – | – | – | – | 4 |
| TMP-SMX | + | – | – | – | + | + | – | – | – | + | – | – | – | – | 4 |
| Cefotaxime | + | – | + | – | + | + | – | – | – | – | + | – | – | – | 5 |
| Cefoxitin | + | – | + | + | + | + | – | – | – | – | – | – | – | – | 5 |
| Ceftriaxone | + | – | + | – | + | + | – | – | – | – | + | – | – | – | 5 |
| Colistin | – | – | – | – | – | + | + | + | + | – | – | – | – | + | 5 |
| Daptomycin | + | + | – | – | – | – | – | – | – | + | – | + | – | + | 5 |
| Doxycycline | + | – | – | – | + | + | – | – | – | + | – | – | + | – | 5 |
| Gentamicin | + | – | – | – | + | + | – | – | + | + | – | – | – | – | 5 |
| Minocycline | + | – | – | – | + | + | – | – | – | + | – | – | + | – | 5 |
| Telavancin | + | + | – | – | – | – | – | – | – | + | + | – | – | + | 5 |
| Tobramycin | + | – | – | – | + | + | – | – | + | + | – | – | – | – | 5 |
| Vancomycin | + | + | – | – | – | – | – | – | – | + | + | – | – | + | 5 |
| Amikacin | + | – | – | – | + | + | – | – | + | + | – | – | – | + | 6 |
| Amoxicillin-clavulanic acid | + | + | + | + | + | + | – | – | – | – | – | – | – | – | 6 |
| Ampicillin-sulbactam | + | + | + | + | + | + | – | – | – | – | – | – | – | – | 6 |
| Cefepime | + | – | – | – | + | + | + | – | + | – | + | – | – | – | 6 |
| Linezolid | + | + | – | – | – | – | – | – | – | + | + | + | – | + | 6 |
| Ticarcillin-clavulanate | + | – | + | + | + | + | – | – | + | – | – | – | – | – | 6 |
| Ceftaroline | + | + | – | – | + | + | + | – | – | + | + | – | – | + | 8 |
| Ciprofloxacin | + | + | – | – | + | + | + | + | + | – | – | – | + | – | 8 |
| Piperacillin-tazobactam | + | + | + | + | + | + | + | – | + | – | – | – | – | – | 8 |
| Ertapenem | + | – | + | + | + | + | + | + | – | – | + | – | – | + | 9 |
| Levofloxacin | + | + | + | – | + | + | + | + | – | – | + | – | + | – | 9 |
| Meropenem | + | – | + | + | + | + | + | + | + | – | + | – | – | + | 10 |
| Moxifloxacin | + | + | + | + | + | + | + | – | – | + | + | – | + | – | 10 |
| Imipenem-cilastatin | + | + | + | + | + | + | + | + | + | – | + | – | – | + | 11 |
| Tigecycline | + | + | + | + | + | + | + | + | – | + | + | + | + | + | 13 |
MSSA = methicillin-susceptible Staphylococcus aureus; E/K = Escherichia coli/Klebsiella; M/H.flu = Moraxella and Haemophilus influenzae; Pseudo = Pseudomonas aeruginosa; MRSA = methicillin-resistant Staphylococcus aureus; PRP = penicillin-resistant pneumococcus; VRE = vancomycin-resistant Enterococcus; atypicals = Mycoplasma pneumoniae and Chlamidophila; MDRO = multidrug-resistant organisms
Further Reading
- Development and Application of an Antibiotic Spectrum Index for Benchmarking Antibiotic Selection Patterns Across Hospitals. Infect Control Hosp Epidemiol. 2017;38(8):993-997. doi: 10.1017/ice.2017.94.
