Fluoroquinolones, Vancomycin, Telavancin, and Bactrim
| MOA | Side Effects | Common uses | Comments | |
| Fluoroquinolones -1st Gen: Nalidixic acid -2nd Gen: Ciprofloxacin, levofloxacin, etc. -3rd Gen: Gatifloxacin -4th Gen: Moxifloxacin and Gemifloxacin |
Inhibits the enzyme DNA gyrase. This causes breakage of the bacterial DNA structure and inhibition of DNA synthesis. | -GI symptoms -Damage to cartilage (don’t give to kids or pregnant women) -Achilles tendonitis -CNS: Headaches, insomnia, CNS -C. diff |
-Covers gram negatives exceptionally well. -Cipro covers Pseudomonas (even though resistance is rising) -Diarrhea caused by enteric organisms (Salmonella, Shigella, Campylobacter or E. col) because high levels are attained in stool. -UTI (high renal & prostate concentrations) -Chronic bone infections (osteomyelitis): Covers Pseudomonas, staph aureus, or Enterobacteriaceae -Covers gram-negative facultative intracellular organisms, including legionella, Brucella, Salmonella, and atypical Mycobacteria -Newer quinolones have expanded gram-positive coverage (Strep Pneumoniae, Staph aureus, and enterococcus faecalis) and also cover atypical bacteria (Legionella, Chlamydia, Mycoplasma). As such, they are good for treating CAP. –Moxifloxacin is used for empiric coverage of intra-abdominal infections because of its good anaerobic coverage and its broad spectrum. |
-Cipro has poor gram-positive coverage. It doesn’t cover streptococcus pneumoniae but covers staph aureus (and also anthrax) – Most quinolones don’t cover anaerobes. The exception is Moxifloxacin which covers anaerobes. -Levaquin covers the gm+s that ciprofloxacin doesn’t. It covers streptococcus pneumoniae, enterococcus faecalis, group A, B, C, G streptococci. It is used to tx CAP. Moxifloxacin=Respiratory quinolone b/c it has strong activity Streptococcus Pneumonia and also has anaerobic coverage. |
| Vancomycin Telavancin |
Inhibits the synthesis of gram-positive peptidoglycan cell wall a step earlier than penicillin. I.e. it inhibits transpeptidation of D-alanine. Telavancin also disrupts cell membrane potential and changes cell permeability due to its lipophilic side chain. |
-Hearing loss (rare) -“Red man syndrome”. This occurs with rapid IV infusion of Vancomycin which stimulates the release of histamine. To prevent this, infuse slowly and give an antihistamine. |
-Covers all gram pos bugs including resistant organisms like MRSA, enterococcus, MDR Staphylococcus epidermidis. -Tx C. dif pseudomembranous colitis -Tx gram positives in patients who are allergic to PCN and cephalosporins. |
–Vancomycin covers ALL GRAM POSITIVE bacteria. -It is the opposite of Aztreonam –Resistance to vancomycin is growing. Telavancin treats bugs that have developed resistance to Vancomycin. |
| Daptomycin | Binds to gram-positive bacteria cell membrane in a calcium-dependent manner > rapid depolarization of membrane potential > rapid inhibition of DNA, RNA, and protein synthesis. This kills the bacteria. | -Myopathy: Monitor baseline CPK enzyme levels and then weekly after you start. -Eosinophilic PNA |
-Broad gram-positive coverage including bugs resistance to both methicillin and vancomycin. – Complicated skin and soft tissue infections. |
Dont use to tx PNA because it has low lung penetration and decreased activity in the presence of pulmonary surfactant. |
| Bactrim (TMP-SMX) | Inhibits bacterial DNA synthesis by: -SMX looks like PABA and competitively inhibits the conversion of PABA to dihydrofolate (DHF). -TMP inhibits the enzyme DHF reductase, blocking conversion of DHF to TH4 (tetrahydrofolate). TH4 is needed to make purines (nucleic acids) that are part of DNA. |
-N/V/D -Skin rashes -Bone marrow suppression; esp. in AIDs patients -Don’t use in pregnancy b/c it causes increased bilirubin levels in the fetus and reduces TH4. Folate deficiency can increase neural tube defects in the first trimester. – Patients with low folate levels can get macrocytic anemia. Coadministering folinic acid will prevent anemia without affecting its antibacterial effect. |
-Wide gram positive and gram negative coverage -Tx Otitis media, sinusitis, bronchitis, and PNA (covers Strep pneumoniae and Haemophilus influenzae) -Tx diarrhea from Shigella, Salmonella, and E. Coli (covers these gram-negatives) -UTI, Prostatitis, and urethritis caused by enterics. -PCP pneumonia in AIDS patients when CD4 counts drop below 200. -Also, tx Toxoplasma and Isospora belli -Nocardia -MRSA outpatient. |
-No Anaerobic coverage. |
TMP-SMX covers: Three Tracts – Respiratory tract, GI tract, and urinary tract. Tracts- Mouth and GI, Pulmonary, and Sifting (the kidneys sifter -UTI).
Source: From Clinical Microbiology made ridiculously simple.