Pharmacopeia
ERYTHROMYCIN
Core pharmacology
- Legacy Cicm Level
Level 3
- Introduction
Macrolide antibiotic
- Absorption
10-60% absorption
Undergoes first pass metabolism- Distribution
Poor CSF penetration but good lung penetration
- Protein binding
85% PB
- Volume of distribution
Vd 0.3-1.2L/kg
- Metabolism
Hepatic demethylation
- Excretion
Renally excreted (15% unchanged)
- Half-life
T1/2= 1.5 hours
- Class Group
ANTIBIOTIC:
MACROLIDE- Presentation
Topical, oral, IV
- Antimicrobial Spectrum
1. Gram positives
2. Anaerobes
Obligate intracellular organisms (legionella, mycoplasma)
Anti-infectives · Anti-infectives
- Mechanism of action
Inhibits 50s subunit to prevent protein synthesis
Bacteriocidal/static- Adverse Effects Toxicity
1. Must be avoided in porphyria
2. Nausea, vomiting, diarrhea
3. Hypersensitivity
4. QT prolongation and increased risk of torsade’s
5. Inhibits CYP3A4 (increased warfarin, carbamazepine, ciclosporin, valproate, tacrolimus, digoxin)
Inhibits p-glycoprotein
Gastrointestinal · Gastrointestinal
- Mechanism of action
Binds motilin receptors in the stomach and duodenum leading to increased LOS tone, increased GIT motility and coordination
- Adverse Effects Toxicity
1. Porphyria
2. QTc prolongation
3. Antibiotic resistance
4. Inhibits CYP3A4 (increased warfarin, carbamazepine, ciclosporin, valproate, tacrolimus, digoxin)
5. Inhibits p-glycoprotein