Cephalexin: Difference between revisions
 
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**Tabs: 250mg, 500mg, 750mg
**Tabs: 250mg, 500mg, 750mg
**Liquid: 125mg/5mL; 250mg/5mL
**Liquid: 125mg/5mL; 250mg/5mL
*Common Trade Names: Keflex
*Common Trade Names: Keflex, Keftab, Biocef


==Adult Dosing==
==Adult Dosing==
Line 18: Line 18:


===[[Cellulitis]] and Other Skin Infections===
===[[Cellulitis]] and Other Skin Infections===
*500mg PO q12h
*60-120 kg: 500 mg Q6H 1 gram Q8H.
*>120 kg: 1 g Q6H. <ref>Reduction of Inappropriate Antibiotic Use and Improved Outcomes by Implementation of an Algorithm-Based Clinical Guideline for Nonpurulent Skin and Soft Tissue Infections.  Ann Emerg Med. 2020 Feb 13. pii: S0196-0644(19)31453-2. doi: 10.1016/j.annemergmed.2019.12.012. [Epub ahead of print]</ref>


==Pediatric Dosing==
==Pediatric Dosing==
===General===
===General===
*25-50 mg/kg/day PO divided q6-12h
*25-50mg/kg/day PO divided q6-12h
*Max: 500mg/dose
*Max: 500mg/dose


===[[Otitis Media]]===
===[[Otitis Media]]===
*75-100 mg/kg/day PO divided q12h x 10 days
*75-100mg/kg/day PO divided q12h x 10 days
*Max: 4,000 mg/24h
*Max: 4,000mg/24h


===Community Acquired [[Pneumonia (Peds)|Pneumonia]] (>3 Months)===
===Community Acquired [[Pneumonia (Peds)|Pneumonia]] (>3 Months)===
*75-100 mg/kg/day PO divided q12h x 10 days
*75-100mg/kg/day PO divided q12h x 10 days


===Streptococcal [[Pharyngitis]] (>1 Year)===
===Streptococcal [[Pharyngitis]] (>1 Year)===
*40 mg/kg/day PO divided q12h x 10 days
*40mg/kg/day PO divided q12h x 10 days
*Max: 500mg/dose
*Max: 500mg/dose


===Skin Infections===
===Skin Infections===
*25-50 mg/kg/day PO divided q12h
*25-50mg/kg/day PO divided q12h
*Max: 500mg/dose
*Max: 500mg/dose


==Special Populations==
==Special Populations==
*[[Drug Ratings in Pregnancy|Pregnancy Rating]]: B
*[[Drug Ratings in Pregnancy|Pregnancy Rating]]: B
*Lactation: Safe
*[[Lactation risk categories]]: Enters breast milk/L3
*Renal
*Renal
**Adult
**Adult
Line 95: Line 96:
*Mechanism of Action:
*Mechanism of Action:
**Bactericidal, inhibits cell wall
**Bactericidal, inhibits cell wall
==[[Antibiotic Sensitivities]]<ref>Sanford Guide to Antimicrobial Therapy 2014</ref>==
{| class="wikitable"
| align="center" style="background:#f0f0f0;"|'''Group'''
| align="center" style="background:#f0f0f0;"|'''Organism'''
| align="center" style="background:#f0f0f0;"|'''Sensitivity'''
|-
| Gram Positive||[[Strep. Group A, B, C, G]]||'''S'''
|-
| ||[[Strep. Pneumoniae]]||'''S'''
|-
| ||[[Viridans strep]]||'''S'''
|-
| ||Strep. anginosus gp||X1
|-
| ||[[Enterococcus faecalis]]||R
|-
| ||[[Enterococcus faecium]]||X1
|-
| ||[[MSSA]]||'''S'''
|-
| ||[[MRSA]]||R
|-
| ||[[CA-MRSA]]||R
|-
| ||[[Staph. Epidermidis]]||I
|-
| ||[[C. jeikeium]]||R
|-
| ||[[L. monocytogenes]]||R
|-
| Gram Negatives||[[N. gonorrhoeae]]||R
|-
| ||[[N. meningitidis]]||R
|-
| ||[[Moraxella catarrhalis]]||R
|-
| ||[[H. influenzae]]||R
|-
| ||[[E. coli]]||'''S'''
|-
| ||[[Klebsiella]] sp||'''S'''
|-
| ||E. coli/Klebsiella ESBL+||R
|-
| ||E coli/Klebsiella KPC+||R
|-
| ||[[Enterobacter]] sp, AmpC neg||R
|-
| ||[[Enterobacter]] sp, AmpC pos||R
|-
| ||[[Serratia]] sp||R
|-
| ||Serratia marcescens||X1
|-
| ||[[Salmonella]] sp||R
|-
| ||[[Shigella]] sp||R
|-
| ||[[Proteus mirabilis]]||'''S'''
|-
| ||[[Proteus vulgaris]]||R
|-
| ||[[Providencia sp.]]||R
|-
| ||[[Morganella sp.]]||R
|-
| ||[[Citrobacter freundii]]||R
|-
| ||[[Citrobacter diversus]]||R
|-
| ||[[Citrobacter sp.]]||R
|-
| ||[[Aeromonas sp]]||X1
|-
| ||[[Acinetobacter sp.]]||R
|-
| ||[[Pseudomonas aeruginosa]]||R
|-
| ||[[Burkholderia cepacia]]||R
|-
| ||[[Stenotrophomonas maltophilia]]||R
|-
| ||[[Yersinia enterocolitica]]||X1
|-
| ||[[Francisella tularensis]]||X1
|-
| ||[[Brucella sp.]]||X1
|-
| ||[[Legionella sp.]]||R
|-
| ||[[Pasteurella multocida]]||R
|-
| ||[[Haemophilus ducreyi]]||X1
|-
| ||[[Vibrio vulnificus]]||X1
|-
| Misc||[[Chlamydophila sp]]||X1
|-
| ||[[Mycoplasm pneumoniae]]||X1
|-
| ||[[Rickettsia sp]]||X1
|-
| ||[[Mycobacterium avium]]||X1
|-
| Anaerobes||[[Actinomyces]]||X1
|-
| ||[[Bacteroides fragilis]]||R
|-
| ||[[Prevotella melaninogenica]]||X1
|-
| ||[[Clostridium difficile]]||X1
|-
| ||[[Clostridium (not difficile)]]||X1
|-
| ||[[Fusobacterium necrophorum]]||X1
|-
| ||[[Peptostreptococcus sp.]]||'''S'''
|}
===Key===
{{Template:Antibacterial Spectra Key}}


==See Also==
==See Also==
Line 100: Line 223:
*[[Cephalosporin Cross-reactivity]]
*[[Cephalosporin Cross-reactivity]]


==Source==
==References==
<references/>
*Sanford 2010
*Sanford 2010
*Epocrates
*Epocrates
*Lexicomp


[[Category:Drugs]]
[[Category:Pharmacology]] [[Category:ID]]

Latest revision as of 23:48, 8 May 2020

General

  • Type: 1st generation cephalosporin
  • Dosage forms
    • Tabs: 250mg, 500mg, 750mg
    • Liquid: 125mg/5mL; 250mg/5mL
  • Common Trade Names: Keflex, Keftab, Biocef

Adult Dosing

General

  • 250-500mg PO q6h
  • Max: 4g/day

Strep Pharyngitis

  • 500mg PO q12h x 10 days

Uncomplicated UTI

  • 500mg PO q12h x 7-14 days

Cellulitis and Other Skin Infections

  • 60-120 kg: 500 mg Q6H 1 gram Q8H.
  • >120 kg: 1 g Q6H. [1]

Pediatric Dosing

General

  • 25-50mg/kg/day PO divided q6-12h
  • Max: 500mg/dose

Otitis Media

  • 75-100mg/kg/day PO divided q12h x 10 days
  • Max: 4,000mg/24h

Community Acquired Pneumonia (>3 Months)

  • 75-100mg/kg/day PO divided q12h x 10 days

Streptococcal Pharyngitis (>1 Year)

  • 40mg/kg/day PO divided q12h x 10 days
  • Max: 500mg/dose

Skin Infections

  • 25-50mg/kg/day PO divided q12h
  • Max: 500mg/dose

Special Populations

  • Pregnancy Rating: B
  • Lactation risk categories: Enters breast milk/L3
  • Renal
    • Adult
      • CrCl 50-90: give q6-8h
      • CrCl 10-50: give q8-12h
      • CrCl <10: give q12-24h
      • Hemodialysis: give dose after dialysis, no supplement
      • Peritoneal dialysis: no supplement
    • Pediatric
      • CrCl 30-50: give q8h
      • CrCl 10-29: give q12h
      • CrCl <10: give q24h
      • Hemodialysis: give dose after dialysis, no supplement
      • Peritoneal dialysis: no supplement
  • Hepatic (Adult & Pediatric)
    • Not defined

Contraindications

Adverse Drug Reactions

Serious

Common

Pharmacology

  • Half-life: 1h (~20hr ESRD)
  • Metabolism: Minimal
  • Excretion: Primarily urine (>90% unchanged)
  • Mechanism of Action:
    • Bactericidal, inhibits cell wall

Antibiotic Sensitivities[2]

Group Organism Sensitivity
Gram Positive Strep. Group A, B, C, G S
Strep. Pneumoniae S
Viridans strep S
Strep. anginosus gp X1
Enterococcus faecalis R
Enterococcus faecium X1
MSSA S
MRSA R
CA-MRSA R
Staph. Epidermidis I
C. jeikeium R
L. monocytogenes R
Gram Negatives N. gonorrhoeae R
N. meningitidis R
Moraxella catarrhalis R
H. influenzae R
E. coli S
Klebsiella sp S
E. coli/Klebsiella ESBL+ R
E coli/Klebsiella KPC+ R
Enterobacter sp, AmpC neg R
Enterobacter sp, AmpC pos R
Serratia sp R
Serratia marcescens X1
Salmonella sp R
Shigella sp R
Proteus mirabilis S
Proteus vulgaris R
Providencia sp. R
Morganella sp. R
Citrobacter freundii R
Citrobacter diversus R
Citrobacter sp. R
Aeromonas sp X1
Acinetobacter sp. R
Pseudomonas aeruginosa R
Burkholderia cepacia R
Stenotrophomonas maltophilia R
Yersinia enterocolitica X1
Francisella tularensis X1
Brucella sp. X1
Legionella sp. R
Pasteurella multocida R
Haemophilus ducreyi X1
Vibrio vulnificus X1
Misc Chlamydophila sp X1
Mycoplasm pneumoniae X1
Rickettsia sp X1
Mycobacterium avium X1
Anaerobes Actinomyces X1
Bacteroides fragilis R
Prevotella melaninogenica X1
Clostridium difficile X1
Clostridium (not difficile) X1
Fusobacterium necrophorum X1
Peptostreptococcus sp. S

Key

  • S susceptible/sensitive (usually)
  • I intermediate (variably susceptible/resistant)
  • R resistant (or not effective clinically)
  • S+ synergistic with cell wall antibiotics
  • U sensitive for UTI only (non systemic infection)
  • X1 no data
  • X2 active in vitro, but not used clinically
  • X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
  • X4 active in vitro, but not clinically effective for strep pneumonia

See Also

References

  1. ↑ Reduction of Inappropriate Antibiotic Use and Improved Outcomes by Implementation of an Algorithm-Based Clinical Guideline for Nonpurulent Skin and Soft Tissue Infections. Ann Emerg Med. 2020 Feb 13. pii: S0196-0644(19)31453-2. doi: 10.1016/j.annemergmed.2019.12.012. [Epub ahead of print]
  2. ↑ Sanford Guide to Antimicrobial Therapy 2014
  • Sanford 2010
  • Epocrates
  • Lexicomp
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