Glycylcyclines

Glycylcyclines are a rarely used class of antibiotics that treat several infections including MRSA, VRE, ESBL producing gram negatives, atypical infections, gram-positive and gram-negative infections, and anaerobic infections. Tigecycline, which is the only glycylcycline, does not cover pseudomonas. Glycylcyclines work by binding to the 30s subunit of the bacterial ribosome, which prevents protein synthesis. Glycylcyclines are bacteriostatic.  Efflux pumps are known bacterial resistance mechanisms – although rare. Some notable adverse effects include hypersensitivity, photosensitivity, and staining of developing teeth.

Class Drugs

• Tigecycline

Class Mechanism of Action

Binds to 30s subunit of bacterial ribosome, which prevents protein synthesis

Bacteriostatic

Class Applications

Broad spectrum antibiotic

Organisms treated

• Gram (+)

S. aureus (MRSA)

• Enterococcus (VRE)

• Streptococcus

• Gram (-)

• ESBL

• Anaerobes

• Atypicals

Class Adverse Effects

Resistance - minimal compared to tetracyclines

• Efflux pumps

Pumps decrease intracellular concentration of drug

Hypersensitivity

• Rashes, angioedema, anaphylaxis

Phototoxicity

• Severe sunburns when exposed to sun

Contraindicated in children less than eight and pregnant and breastfeeding women

• Dental hypoplasia and deposits in calcified tissue

Slowing of bone growth

Hepatotoxicity

Esophagitis/gastritis

Pseudotumor cerebri

Increased mortality with use in some studies

Drug Table

Drug Name	Application	Comments	Image
Tigecycline			"Tiger" "Cycling"