Other ATB

What are the classifications of broad-spectrum antibiotics mentioned in the notes?

Macrolides, lincosamides, aminoglycosides, tetracyclines.

What type of antibiotics are primarily bacteriostatic?

Macrolides.

What are the two subunits of the 70S ribosome involved in antibiotic action?

50S and 30S.

What is the process called where the amino acid chain is elongated by tRNA in the ribosome?

Transpeptidation.

What is the antimicrobial spectrum of macrolides?

G+ bacteria, some G- bacteria, anaerobic pathogens, intracellular pathogens, spirochetes, and mycobacteria.

Which macrolide is known as an azalide?

Azithromycin.

What is the main mechanism of action for macrolides?

Reversible binding to the 50S subunit of bacterial ribosomes.

What are common side effects of macrolides?

GI disturbances, ototoxicity, skin allergic reactions, elevated liver enzymes.

For which infections are macrolides generally used?

Atypical pneumonia, dental infections, Chlamydia infections, and as an alternative to penicillin.

How is azithromycin absorbed and what is its oral bioavailability?

Oral absorption is ~37%.

What is a significant pharmacokinetic characteristic of clarithromycin?

Its plasma half-life is three times longer than that of erythromycin.

Clarithromycin is used against

Generally RTIs and as an alternative to PNC in strep throat

• Mycoplasma

• Chlamydia

• Atypical mycobacteria

• HP infections

What type of bacteria are aminoglycosides primarily effective against?

Aerobic bacteria.

How do aminoglycosides achieve their bactericidal effect?

By irreversible binding to the 30S ribosomal subunit.

What is the typical application route for streptomycin?

Intramuscular or intravenous.

What adverse effect is commonly associated with aminoglycosides?

Nephrotoxicity and ototoxicity.

What can lead to cross-resistance among aminoglycosides?

Inactivation by enzymes and altered transport mechanisms.

Which antibiotic class does clindamycin belong to?

Lincosamides.

What types of infections is clindamycin effective against?

Anaerobic infections and sensitive strains of G+ bacteria.

What is a serious side effect associated with clindamycin therapy?

Pseudomembranous colitis due to C. difficile.

How is clindamycin metabolized and excreted?

Primarily in the liver with renal and biliary excretion.

Which two types of bacteria do tetracyclines have significant activity against?

G+ and G- bacteria.

What are the major pharmacokinetic properties of doxycycline?

Well-absorbed (80%) and long elimination half-life (12 to 25 hours).

Do tetracyclines influence Pseudomonas spp.?

No, tetracyclines do not affect Pseudomonas spp.

What adverse reactions are associated with tetracyclines?

Photosensitivity, teeth discoloration, and hepatotoxicity.

Which antibiotics are known for causing resistance issues among S. pneumoniae?

Macrolides.

What antibiotic class does vancomycin belong to?

Glycopeptide antibiotics.

What mechanism of action does vancomycin have?

Inhibits cell wall synthesis by binding to the D-ala residues.

What types of infections is vancomycin indicated for?

MRSA, enterococcal infections, and pseudomembranous colitis.

What is a common side effect of vancomycin when administered intravenously?

Red man syndrome.

What is the main indication for using linezolid?

Serious infections caused by G+ organisms including MRSA.

What severe side effect can occur with prolonged use of linezolid?

Bone marrow suppression.

Describe the mechanism of action of daptomycin.

Binds to bacterial cell membranes causing depolarization and loss of membrane potential.

What is the main therapeutic use of tigecycline?

Complicated skin and soft tissue infections.

Which antibiotic may cause contact dermatitis as a side effect?

Fusidic acid.

What is a common clinical use of rifaximin?

Treatment for hepatic encephalopathy and traveler's diarrhea.

What type of antibiotic is telithromycin and what is its significance?

The first ketolide, designed to overcome ERY resistance in G+ cocci.

What is a notable pharmacokinetic property of azithromycin?

Long terminal half-life of up to 5 days.

What are the applications of aminoglycosides in clinical scenarios?

Severe aerobic infections, endocarditis, and postoperative infections.

How do aminoglycosides work in treating tuberculosis?

They are used in conjunction with cell wall-active agents.

Name a structural feature common to all macrolides.

Macrocyclic lactone ring.

What phenomenon is associated with macrolides and their potential drug interactions?

Inhibition of the CYP450 enzyme system.

What is the upsurge in resistance rates related to in treating pneumonia?

Multidrug-resistant strains of Streptococcus pneumoniae.

What infection is commonly treated with spectinomycin?

Gonorrhea, especially in patients allergic to penicillins.

Which drug class is known for its potential to cause 'grey syndrome' in newborns?

Chloramphenicol.

What role does pharmacokinetics play in the dosing of aminoglycosides?

Their dosing reflects plasma levels rather than the dose used.

What characteristic of aminoglycosides affects their dosing schedule?

Prolonged post-antibiotic effect (PAE).

What are the main characteristics of chloramphenicol toxicity?

Aplastic anemia and disruption of erythroid cell proliferation.

What is the primary mechanism of action of lincosamides?

Interference with RNA at the 50S ribosomal subunit.

How does Rifampicin differ from rifaximin in its absorption characteristics?

Rifaximin is poorly absorbed (<1%) and acts locally.

What is the pharmacological relevance of the term 'MLSB resistance'?

Resistance to macrolides, lincosamides, and streptogramin B antibiotics.