3.4 - Inhibition of Protein Synthesis Flashcards
What antibiotics inhibit protein synthesis in the microorganism?
–> Aminoglycosides
–> Macrolides
–> Tetracyclines
–> Chloramphenicol
What are the names for the top and bottom portion of a ribosome?
Top: 50S
Bottom: 30S
Where do aminoglycosides act?
By changing the shape of 30S
What kind of drugs are gentamicin and tobramycin?
What are they used to treat?
Are they charged or uncharged? How are they administered?
Adverse effects?
Aminoglycosides
–> Gram- aerobic
–> Charged
–> i.v or i.m.
–> Nephrotoxicity and ototoxicity
What is ototoxicity?
A drug that can cause damage to the auditory or vestibular functions of the ears.
What kind of drugs are clarithromycin and azithromycin*?
What kind of bacteria and infections do they treat?
Adverse effects?
Macrolides
–> Gram + (Useful substitute for penicillin if people display hypersensitivity)
–> Respiratory infections, (chlamydia, gonorrhea)*
–> NV&D
Where do macrolides act on the ribosome?
Binds to 50S and prevents translocation-movement of ribosome along mRNA
What are some adverse effects specific to clarithromycin?
Inhibit hepatic (p450s) enzymes
–> Risk of toxicity for any drug normally metabolized and inactivated by the liver
Which drugs act on 50S?
Macrolides:
–> Azithromycin
–> Clarythromycin
–> Linezolid
–> Clindamycin
–> Chloramphenicol
What class of drug is clindamycin? What is it used to treat?
Lincosides (acts like macrolides)
–> Used to treat soft tissue infections (Cellulitis, bites), especially for allergy to beta-lactams and bacterial vaginosis
What class of drug is linezolid? What is it used to treat?
Member of oxazolidinones
–> used to treat infections that are otherwise resistant to VRE and MRSA
Where on the ribosome do tetracyclines act?
30S
–> Interferes with attachment of tRNA to mRNA-ribosome complex
Where on the ribosome does chloramphenicol act?
binds to 50S portion and inhibits formation of peptide bond
What kinds of drugs are tetracyline, doxycycline, and minocycline?
What are they used to treat?
Precautions?
Tetracyclines
–> Broad spectrum; widespread resistance
–> High affinity for bone and teeth, interacts with milk, antacids, calcium, and iron (decrease drug absorption)
–> Risk of superinfections
–> Photosensitivity
–> Avoid if pregnant
What specific infections is tetracycline used to treat?
Acne & H. Pylori
What specific infection is doxycycline used to treat?
Chlamydia
What antibiotic interacts with milk, antacids, iron, and calcium, and therefore have a high affinity for bone and teeth?
Tetracyclines
–> Discoloration of teeth between 4 months to 8 years of age
What are some precautions of chloramphenicol?
Why and what do we still use it for?
It was widespread resistance, and suppresses bone marrow functions in some individuals(anemia, bleeding issues, immunosuppression), newborns lack the enzymes to conjugate drug (phase two) and can cause cyanosis;
but, it is broad spectrum and has good distribution to the brain.
–> Rickettseal disease
–> Meningitis
–> Typhoid fever
–> Cholera
What drug causes gray baby syndrome?
Toxic accumulation of chloramphenicol causes cyanosis in newborns because they lack the enzymes to conjugate the drug during metabolism
What is agranulocytosis?
Low granulocytes
What is thrombocytopenia?
Low platelet count
