Antibiotics part 2

bacterial protein synthesis inhibitors

• inhibits protein synthesis by binding to ribosomal subunits (30 or 50) - distrupting translation

• selective toxicity!!: target bacterial ribosomes without affect human ribosomes

• notes: OLDER ADULTS are at risk of toxicity b/c of renal and hepatic function - also monitor for prolonged use

• COVERS: MALTO

  • macrolides, aminoglycosides, lincosamides, tetracyclines, oxazolidinones

tetracyclineS

• bind to 30s ribosomes, stops translation to prevent making proteins

• BROAD: for gram+ and gram- and atypical pathogens (rickets and lyme)

• other: doxycycline

• USE: res and GI infections, chlamydia, H. pylori ulcers, lyme

• ADR: PHOTOSENSITIVITY, upset GI, diarrhea,

• consid: avoid with food, dairy, antacids and iron supplements, and take on empty stomach (1 hour before or 2 hours after eating) with water!, avoid sunlight, avoid laying down after taking it

doxycycline

class: protein synthesis inhibitor, tetracycline

diff: LONGER HALF-LIFE (used more often than tetra) and CAN be taken with food

USE: BROAD + and -, LYME, moutain fever, malaria prophylaxis, chlamydia, acne, community acquired pneumonia and atypical pneumonias(first line),

MOA: 30s

ADR: hepatox, SJS, C. diff, NVD, photo, throat irritation

Dont: pregnancy, under 8yrs

consid: take with water, can be taken with food, educate on sunscreen and avoid excessive sun, avoid laying down after taking med

macrolides -think of rin

• bind to 50s - prevents elongation

• gram+ and some gram- PREFERRED WITH PENICILLIN ALLERGY

• drugs: azithromycin, clarithromycin

• USE: chlamydia, group a strep, res infections

• considerations: azithro has fewer GI side effects

aminoglycosides

MOA: 30s

NARROW - oxygen gram-negative bacteria (E. coli)

drugs: amikacin, kanamycin, neomycin

USE: serious systemic infections: endocarditis (heart), septicemia(blood), pneumonia

consid: oto and nephro tox, monitor peak and trough levels (DO NOT GIVE IF IT IS NOT LOW ENOUGH - know before you give it)

lincosamides drug example

clindamycin

oxazolidinones drug example

linezolid

chloramphenicol - one of the first discovered to inhibit bacterial protein synthesis

MOA: inhibit 50s - NOT FIRST LINE

BROAD - gram +,- and anaerobes

USE: serious infections: typhoid fever, meningitis

ADR: bone marrow suppression, aplastic anemia, gray baby syndrome!!!

considerations: monitor blood count, avoid using on neonates, only use to resistant or threatening infections

nucleic acid synthesis inhibitors

MOA: disrupts bacterial DNA replication, transcription, or repair - target specific enzymes

spectrum: BROAD - gram +,-, anaerobic

consideration: not interchangeable - monitor or resistance development and drug specific

nucleic acid synthesis inhibitors examples

fluorquinolones

rifamycins

metronidazole

nitrofurantonin

fluorquinolones

MOA: inhibts DNA synthesis

BROAD - Gram- and newer gram +

USE: UTI, res, bone, joint infecs, infectious diarrhea

ADR: QT prolongation, tendon ruptor, tendonitis, phototoxicity, peripheral neuropathy, C diff, confusion, seizures, allergic reactions

fluorquinolones endings

-floxacin

examples: ciproflaxcin, levofloxacin, moxifloxacin, oflofloxacin

disruptors of cell membrane

• compromise bacterial membrane - causing ion leakage and cell death

• examples: polymyxins (-, UTI, renal neurtox) and daptomycin (gram +, MRSA, myopathy, CPK)

Inhibitors of metabolic pathways

target metabolic pathways that interfere with folic acid synthesis

BROAD SPECT - USE: UTIs, pneumocystis jiroveci pneumonia(PJP), infections

examples: sulfonamides(block production of folic acid), trimethoprim(blocks the activation of folic acid)

• both work synergistically