Tetracyclines Flashcards
Tetracyclines and Glycylcyclines
Doxycycline
Minocycline
Tetracycline
Tigecycline
Once considered broad spectrum; now used for niche indications
Useful (but not highly studied) for common respiratory tract infections; drugs of choice for uncommon infections
Doxy is preferred in most situations
Tige evades most tetracycline resistance mechanisms and has a broad spectrum
Tetracyclines and Glycylcyclines MOA
Bind to bacterial ribosome (30S subunit) preventing the docking of tRNA carrying new amino acids for addition to the elongating protein chain
Tetra, Doxy, Mino Spectrum
Good Atypicals Rickettsia Spirochetes (Borrelia burgdorferi, Helicobacter pylori) Plasmodium species (malaria)
Moderate
Staph (including MRSA)
S. pneumo
Poor
Most GNRs
Anaerobes
Enterococci
Tigecycline Spectrum
Good Atypicals Enterococci (including VRE) Staph (including MRSA) S. pneumo
Acceptable
Most GNRs
Anaerobes
Poor
Pseudomonas
Proteus
Providencia
Tetracyclines and Glycylcyclines Adverse Effects
GI
Can cause esophageal irritation (take with water and standing up if possible)
Tige is IV but can cause severe N/V/D
Dermatologic
Photosensitivity; avoid sun or use sunscreen
Sensory
Mino may cause dizziness and vertigo
Developmental
Can cause discoloration of developing teeth; contraindicated in pregnant women and children < 8yo
Tetracyclines and Glycylcyclines Important Facts
Doxy and Mino bioavailability is ~100%; Tige is IV only
Tetracyclines chelate cations; oral bioavailability is significantly decreased (like FQ); separate by 2 hours or take a week off
Food substantially decreases absorption of tetracycline; minimally of other two
Doxy does not need to be adjusted in renal or hepatic dysfunction
Tetra is renally eliminated; do not use in cases of renal insufficiency (can worsen renal dysfunction)
Tige has a very high volume of distribution (distributed highly into many tissues)- low bloodstream concentrations (not ideal for primary bloodstream infections)
Eliminated hepatically and achieves low urinary concentrations (probably should not be used for UTIs
FDA analysis across all indications showed it to have a mortality disadvantage compared to other antibiotics; driven largely by a study of HA pneumonia; it does have activity against many highly resistant organisms (those types of infections don’t usually make it to clinical studies)
Tetracyclines and Glycylcyclines Good For
Uncomplicated respiratory tract infections: (acute exacerbations of chronic bronchitis, sinusitis, and CA pneumonia)
Drugs of choice for many tick borne diseases
Alternative drugs for (skin or soft tissue infections, syphilis, pelvic inflammatory disease with cefoxitin)
Alternative to Ciprofloxacin in bioterrorism scenarios (active against anthrax, plague, and tularemia)
Malaria prophylaxis and treatment
Tige may have role in treatment of complicated polymicrobial infections (intraabdominal, complicated skin and skin structure)
Tetracyclines and Glycylcyclines Important Facts
Doxy and Mino bioavailability is ~100%; Tige is IV only
Tetracyclines chelate cations; oral bioavailability is significantly decreased (like FQ); separate by 2 hours or take a week off
Food substantially decreases absorption of tetracycline; minimally of other two
Doxy does not need to be adjusted in renal or hepatic dysfunction
Tetra is renally eliminated; do not use in cases of renal insufficiency (can worsen renal dysfunction)
Tige has a very high volume of distribution (distributed highly into many tissues)- low bloodstream concentrations (not ideal for primary bloodstream infections)
Eliminated hepatically and achieves low urinary concentrations (probably should not be used for UTIs
FDA analysis across all indications showed it to have a mortality disadvantage compared to other antibiotics; driven largely by a study of HA pneumonia; it does have activity against many highly resistant organisms (those types of infections don’t usually make it to clinical studies)
Tetracyclines and Glycylcyclines Good For
Uncomplicated respiratory tract infections: (acute exacerbations of chronic bronchitis, sinusitis, and CA pneumonia)
Drugs of choice for many tick borne diseases
Alternative drugs for (skin or soft tissue infections, syphilis, pelvic inflammatory disease with cefoxitin)
Alternative to Ciprofloxacin in bioterrorism scenarios (active against anthrax, plague, and tularemia)
Malaria prophylaxis and treatment
Tige may have role in treatment of complicated polymicrobial infections (intraabdominal, complicated skin and skin structure)
