Tetracyclines and Lincosamides Flashcards
Tetracycline drugs include:
Tetracycline (PO, IV, IM)
Doxycycline (PO, IV)
Minocycline (PO, IV)
Tetracyclines’ MOA:
Reversible binding to the 30S ribosomal unit
Prevents tRNA from binding to rRNA which inhibits protein synthesis
How are tetracycline and doxycycline and monocycline different?
Tetracycline is hydrophillic and renally eliminated
Doxycycline and monocycline are lipophillic and hepatically metabolized
AE of tetracyclines include:
GI distress (minimized with food)
Phototoxicity (doxycycline)
Dose related vestibular toxicity (minocycline)
Hepatotoxicity (less with tetracycline)
Permanent tooth discoloration, tooth enamel defects, bone growth retardation in children
DI of tetracyclines:
Dairy products, iron, antacids/laxatives containing cations can decrease absorption (except doxy)
What is minocycline often used for?
Acne vulgaris
Tetracyclines are commonly used for what organisms and are they static/cidal?
Static
Used for: chlamydia, rickettsia, mycoplasma pneumoniae, borrelia
What drug is similar to tetracyclines but affects the 50S ribosomal subunit rather than the 30S?
Chloramphenicol
Is chloramphenicol effective PO?
Yes, it penetrates membranes well and is able to reach the CNS
How is chloramphenicol metabolized and how does this affect DI?
Hepatically via conjugation
Inhibition of CYP450
What is chloramphenicols’ spectrum?
Broad spectrum including anaerobes
AE of chloramphenicol include:
Toxic bone marrow suppression, aplastic anemia, Gray Baby Syndrome
What ribosomal subunit does Clindamycin affect?
50S (same as chloramphenicol)
Bacteriostatic
Which type of organism is Clindamycin effective against?
Anaerobes (also Gram + and Gram-)
AE of clindamycin include:
Less common than chloramphenicol Blood dyscrasias(eosinophilia, leukopenia, thrombocytopenia) Pseudomembranous colitis Rash n/v/*D
