Protein synthesis inhibitors Flashcards
What are examples of antibiotics that are generally bacteriostatic except for one?
Macrolides, clindamycin, tetracyclines, chloramphenicol, fusidic acid (all are bacteriostatic except aminoglycosides, which are bactericidal).
Example sentence: Aminoglycosides like gentamicin are bactericidal.
What is the prototype of macrolides?
Erythromycin.
Prototype refers to the first drug of its kind.
Name some common macrolides.
Azithromycin, clarithromycin, erythromycin, spiramycin.
Example sentence: Azithromycin is commonly used for respiratory infections.
For which patients are macrolides the drug of choice (DOC)?
Patients with penicillin allergy or resistance.
DOC stands for drug of choice.
Which infections are macrolides effective against?
Atypical infections such as chlamydia and mycoplasma pneumonia.
Example sentence: Macrolides are used for atypical pneumonia caused by Legionella pneumophila.
What is the pregnancy category classification of azithromycin and erythromycin?
Category B (safe during pregnancy).
Pregnancy categories indicate the safety of drugs during pregnancy.
What is the pregnancy category classification of clarithromycin?
Category C (not safe during pregnancy).
Category C drugs have shown adverse effects on animal fetuses.
Why must oral erythromycin be enteric coated?
It is destroyed by gastric acid.
Enteric coating protects the drug from being broken down in the stomach.
What are the indications for using macrolides?
- Patients with B-lactam allergy
- Alternative to tetracycline for urogenital chlamydia infection in pregnancy and mycoplasma pneumonia in children
- Gingivitis (spiramycin)
- Whooping cough (pertussis)
- Respiratory infections
- Endocarditis prophylaxis in pediatrics
- Acne (erythromycin with zinc)
- H. pylori eradication (clarithromycin).
B-lactam refers to penicillin and related antibiotics.
What are some common side effects of macrolides?
Gastric upset, bitter taste, transient ototoxicity, QT prolongation with ventricular tachycardia.
QT prolongation can lead to serious heart rhythm abnormalities.
Why should macrolides be used with caution in patients with liver diseases?
They are contraindicated in liver diseases.
Contraindicated means not recommended for use.
How frequently should erythromycin be administered?
Four times a day (1*4).
1*4 means once every 4 hours.
How frequently should clarithromycin be administered?
Twice a day (1*2).
1*2 means once every 12 hours.
How frequently should azithromycin be administered?
Once a day (1*1).
1*1 means once daily.
Why do macrolides have a high risk of drug-drug interactions (DDI)?
They are Cytochrome P450 inhibitors and can’t be used with drugs like theophylline and loratadine.
Cytochrome P450 is an enzyme responsible for drug metabolism.
