NURS 2042 - Antibiotics Pt 3

What is the mechanism of action (MOA) of aminoglycosides and their general spectrum?

Aminoglycosides kill bacteria by inhibiting protein synthesis and are narrow spectrum, primarily used for gram-negative microorganisms.

Why are aminoglycosides not given orally?

They are poorly absorbed in the GI tract.

What are the therapeutic uses of aminoglycosides?

Used for tuberculosis, septicemia, E. coli, eye and ear infections, and hepatic encephalopathy.

What are the adverse effects associated with aminoglycosides?

Nephrotoxicity, ototoxicity, and neuromuscular blockade.

What is the mechanism of action of glycopeptides and their bacterial target?

Glycopeptides inhibit bacterial cell wall synthesis by causing cell death through wall disruption; they are narrow spectrum but can be used broadly, especially against gram-negative bacteria.

What infections can glycopeptides treat?

Skin infections and MRSA.

What are common adverse effects of glycopeptides, including Vancomycin?

Ototoxicity, injection site reactions, nephrotoxicity, QT interval prolongation, secondary infections (e.g., oral thrush, vaginitis), nausea, vomiting, diarrhea, and coagulation interference.

What precaution should be taken when using Vancomycin?

Must draw toxic/serum levels to minimize adverse effects.

What is the mechanism of action of macrolides and their bacterial targets?

Macrolides inhibit protein synthesis in susceptible bacteria; they are both bacteriostatic and bactericidal, effective against gram-positive and gram-negative organisms.

What infections are macrolides commonly used to treat?

Respiratory, GI tract, skin, soft tissue infections, STIs, and C. Diff (only Fidaxomicin).

What are common side effects of macrolides?

Headaches, skin rash, gastrointestinal disturbances like diarrhea, nausea, abdominal pain, and vomiting.

What are rare but serious adverse effects of macrolides?

Clostridioides difficile infection (CDI), vaginitis, ototoxicity, candidiasis, and hearing loss with prolonged use.

What is the mechanism of action of oxazolidinones and what bacteria do they target?

They inhibit protein synthesis in bacterial cells and are effective against gram-positive bacteria; also reversible MAOIs.

What are common therapeutic uses of oxazolidinones?

Community-acquired pneumonia, VRE, and MRSA.

What are the adverse effects of oxazolidinones?

GI irritation (nausea/vomiting), headache, severe diarrhea (report immediately), secondary infections, lactic acidosis, seizures, and visual neuropathy.

What is the general mechanism of action of quinolones and their spectrum?

Quinolones (specifically fluoroquinolones) inhibit bacterial DNA replication and are broad spectrum, effective against gram-positive and gram-negative bacteria.

What enzyme do fluoroquinolones target?

DNA topoisomerase (also known as DNA gyrase), halting DNA replication.

What are common uses of fluoroquinolones?

Eye infections, chest infections, UTIs, infectious diarrhea, respiratory infections, skin infections, STIs, shigellosis, gonorrhea, bone and joint infections.

What are the main adverse effects of fluoroquinolones?

Nausea, vomiting, diarrhea, dizziness, hypoglycemia, phototoxicity, hepatotoxicity, nephrotoxicity, tinnitus, and irreversible peripheral neuropathy.

What populations should avoid fluoroquinolones?

Pregnant patients and individuals under 18 years old.

What drug interactions are associated with fluoroquinolones?

Antacids and NSAIDs.

What is the mechanism of action of sulfonamides?

Sulfonamides are not true antibiotics but are effective antibacterials that inhibit bacterial biosynthesis of folic acid.

What spectrum do sulfonamides cover, and what are their uses?

Broad spectrum; used for UTIs, ear infections, and prevention of strep or rheumatic fever in penicillin-allergic patients.

What are common adverse effects of sulfonamides?

Nausea, vomiting, anorexia, diarrhea, rash, photosensitivity, dizziness, and tinnitus.

What lab should be monitored during sulfonamide therapy?

CBC with differential.

What drugs interact with sulfonamides?

Oral hypoglycemics, warfarin, methotrexate, phenytoin, and ACE inhibitors.

What is the mechanism of action of tetracyclines and their spectrum?

Tetracyclines inhibit protein synthesis in bacterial cells and are bacteriostatic; they are broad spectrum, effective against gram-positive and gram-negative bacteria.

What infections are treated with tetracyclines, especially in penicillin-allergic patients?

STIs, UTIs, respiratory infections, pneumonia, meningitis, acne, and complicated intra-abdominal infections.

What are rare but notable diseases treated with tetracyclines?

Rocky Mountain spotted fever, Lyme disease, anthrax, tularemia, and cholera.

What are common adverse effects of tetracyclines?

Headache, dizziness, nausea, vomiting, abdominal pain, diarrhea, photosensitivity, and esophageal irritation.

Who should not receive tetracyclines?

Pregnant individuals and children under 8 years old.

What are major drug interactions with tetracyclines?

Warfarin (increases anticoagulant effect) and oral contraceptives (reduces effectiveness).