- Amoxicillin
- Azithromycin
- Cephalexin
- Cefazolin
- Cefepime
- Cefotaxime
- Ciprofloxacin
- Ceftriaxone
- Clindamycin
- Doxycycline
- Gentamicin
- Levofloxacin
- Metronidazole
- Piperacillin-Tazobactam
- Vancomycin

Amoxicillin
Rapid Review
- Mechanism of Action: Beta-lactam antibiotic; inhibits bacterial cell wall synthesis.
- Indications: Typically used for otitis media, strep pharyngitis, sinusitis, and community acquired pneumonia.
- Contraindications: allergy to class/drug
- Dosage: General: 500 – 1000 mg q12h x 10 days
- Half-Life: 30 – 90 minutes
- Adverse Reactions: Common reactions: nausea, vomiting, diarrhea, rash. Serious reactions: anaphylaxis, SJS/TEN, hypersensitivity vasculitis.
- Special Considerations: N/A
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Azithromycin
Rapid Review
- Mechanism of Action: Macrolide antibiotic;
- Indications: community-acquired pneumonia, sinusitis, pharyngitis, COPD exacerbations, and genital infections.
- Contraindications: allergy/hypersensitivity to macrolides
- Dosage: Typically a tapered dose of 500 mg PO on day 1, then 250 mg PO x 4 days). Often a single 1-2 gram dose for sexually transmitted infections.
- Half-life: 68 hours
- Adverse Reactions: vomiting, diarrhea, headache, vision changes. May also cause prolonged QT or hepatic necrosis.
- Special Considerations: None
Pearls

Cephalexin
Rapid Review
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Deep Dive

Cefazolin
Rapid Review
- Mechanism of Action: 1st generation cephalosporin; inhibits cell wall mucopeptide synthesis.
- Indications: Frequently used for cellulitis, osteomyelitis, and intra-abdominal infections. May also be used for surgical prophylaxis.
- Contraindications: allergy to class/drug
- Dosage: generally 500-1000 mg IM/IV q6-8hrs.
- Half-life: 1.8 hours
- Adverse Reactions: GI effects (nausea/vomiting/diarrhea). Hypersensitivity reactions.
- Special Considerations: N/A
Pearls
Deep Dive

Cefepime
Rapid Review
- Mechanism of Action: 4th-generation cephalosporin antibiotic; inhibits cell wall mucopeptide synthesis.
- Indications: empiric treatment for severe infections (sepsis, bacteriemia, multi-drug resistant infections, hospital-acquired pneumonia)
- Contraindications: allergy to class/drug
- Dosage: Generally 1-2 g IV/IM q12 hours
- Half-life: 2-19 hours (depending on dose/route)
- Adverse Reactions: GI effects (nausea/vomiting/diarrhea). Hypersensitivity reactions.
Pearls
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Cefotaxime
Rapid Review
- Mechanism of Action: 3rd-generation cephalosporin antibiotic; inhibits bacterial wall synthesis
- Indications: Commonly used to treat intra-abdominal infections, meningitis, gonorrhea, and pneumonia.
- Contraindications: allergy/hypersensitivity to drug class
- Dosage: generally 1-2 g IV/IM q6-12 hrs
- Half-life: 1-2 hrs
- Adverse Reactions: local reaction to injection site, GI effects, hypersensitivity
Pearls
Deep Dive

Ciprofloxacin
Rapid Review
- Mechanism of Action: Fluoroquinoline antibiotic; inhibits DNA gyrase
- Indications: Commonly used for diverticulitis, colitis, and urinary tract infections.
- Contraindications: allergy to class/drug, administration with tizanidine
- Dosage: Generally 250-750mg PO q12h or 200-400mg IV q12hrs.
- Half-life: 4 hours
- Adverse Reactions: GI effects (nausea/vomiting/diarrhea), tendon rupture
Pearls

Ceftriaxone
Rapid Review
- Mechanism of Action: 3rd generation cephalosporin with broad-spectrum gram-negative activity. Inhibits cell wall synthesis
- Indications: Bacterial meningitis, gonorrhea, pelvic inflammatory disease, joint infection
- Contraindications: Allergy to class/drug, age < 1 month
- Dosage
- Generally 1-2 grams IM/IV q24hrs
- Gonorrhea: 500 mg IM (single dose)
- Half-life: 5.8 – 8.7hrs
- Adverse Reactions: Anaphylaxis, bronchospasm, SJS, diarrhea, eosinophilia
Pearls

Clindamycin
Rapid Review
- Mechanism of Action: Lincosamide antibiotic; bacteriostatic/bactericidial
- Indications: odontogenic infections, MRSA, necrotizing soft tissue infections
- Contraindications: allergy to class/drug; ulcerative colitis
- Dosage: generally 150-450mg PO q6 hrs; 1200-2700mg/day IV/IM q6-12 hrs
- Half-life: 2.5-3 hours
- Adverse Reactions: GI effects (nausea/vomiting/diarrhea), pruritus, thrombocytopenia.
- Special Considerations: clindamycin should be used rarely due to high risk of clostridium difficile associated diarrhea.
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Doxycycline
Rapid Review
- Mechanism of Action: Tetracycline; inhibits bacterial protein synthesis after specific ribosomal binding
- Indications: Community-acquired pneumonia, cellulitis, bacterial sinusitis, chlamydia/gonorrhea, PID, lyme disease
- Contraindications: Allergy to drug/class, pregnancy, Age < 8 years old (due to teeth staining, although short courses are permissible)
- Dosage: Generally 100mg PO/IV daily or q12 hours x 7 days
- Onset: Peak concentration after 2-4 hours
- Duration: Half life of 18 hours
- Adverse Reactions: Headache, nausea, dyspepsia, tooth discoloration (controversial), C. Diff diarrhea
- Special Considerations: None
Pearls
Deep Dive

Gentamicin
Rapid Review
- Mechanism of Action: Aminoglycoside; bactericidal antibiotic with broad coverage against aerobic gram-negative bacteria, including Pseudomonas. Binds to the 16s rRNA at the 30s ribosomal subunit, disrupting mRNA translation.
- Indications: PID, sepsis, meningitis, endocarditis, blepharitis
- Contraindications: Allergy to drug/class
- Dosage: Generally 5-7 mg/kg IV q24 hours
- Onset: Reaches peak concentrations after 30-90 minutes
- Duration: 2-3 hours
- Adverse Reactions: Ototoxicity, renal toxicity, abnormal LFTs, rashes
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Levofloxacin
Rapid Review
- Mechanism of Action: 3rd generation Fluoroquinolone; inhibits bacterial DNA synthesis. Broad spectrum antibiotic with good coverage against both gram positive and gram negative organisms.
- Indications: Pneumonia (community or nosocomial), pyelonephritis, UTI, sinusitis, prostatitis.
- Contraindications: QT prolongation, hypersensitivity, myasthenia gravis
- Dosage:
- Pyelonephritis: 250 mg PO daily X 10 days
- Prostatitis: 500 mg PO X 28 days
- Pneumonia: 750 mg PO/IV q24 hours X 7-14 days
- Half-life: 6-8 hours (27-35 hours in adults with renal impairment)
- Adverse Reactions: Tendon rupture, photosensitivity, nausea, prolonged QT
- Special Considerations: Has limited coverage against pseudomonas compared to ciprofloxacin
- Levofloxacin is a fluoroquinolone antibiotic that is commonly used to treat pneumonia and COPD exacerbation
Pearls
Deep Dive

Metronidazole
Rapid Review
- Mechanism of Action: Nitroimidazole antibiotic/anti-protozoan. Inhibits protein synthesis by interacting with DNA.
- Indications: Intra-abdominal infections (colitis, diverticulitis), genital infections (pelvic inflammatory disease, bacterial vaginosis, trichomoniasis) C. difficile, amebiasis
- Contraindications: Hypersensitivity, 1st trimester pregnancy
- Dosage:
- Intra-abdominal infections: 500 mg IV q8 hours
- Genital infections (PID, BV, Trich): Generally 500 mg PO q12 hours X 7 days
- Half-life: 8 hours
- Adverse Reactions: Headache, vaginitis, nausea, confusion, neuropathy
- Special Considerations: Patient should avoid alcohol consumption while on this medication and at least 2-3 days after last dose (creates a disulfiram-like effect)
Pearls
Deep Dive

Piperacillin-Tazobactam
Rapid Review
- Mechanism of Action: Antipseudomonal penicillin. Piperacillin inhibits cell wall mucopeptide synthesis, tazobactam inhibits the beta lactamase enzyme to prevent bacteria from destroying the piperacillin.
- Indications: Pneumonia, sepsis, pelvic inflammatory disease, intra-abdominal infections.
- Contraindications: Hypersensitivity
- Dosage:
- Half-life: 0.7-1.2 hours
- Adverse Reactions: Anaphylaxis, SJS, nausea/vomiting, headache
Pearls
Deep Dive

Vancomycin
Rapid Review
- Mechanism of Action: Glycopeptide antibiotic; inhibits cell wall synthesis, exhibiting a bactericidal action. Very potent against gram-positive bacteria.
- Indications: Sepsis, MRSA skin and soft tissue infections, endocarditis, meningitis, C difficile colitis
- Contraindications: Allergy to class/drug
- Dosage: Initial loading dose generally 15-20mg/kg IV. Maintenance dose is 500-1000 IV q12 hours.
- Onset: Rapid
- Duration: Half life of 4-6 hrs
- Adverse Reactions: Hypotension (with rapid IV use), “red man syndrome”, nausea
- Special Considerations: None
Pearls