37.aminoglycoside antibiotics

Question 1

what are aminoglycosides

Answer 1

• used for the treatment of serious infections due to aerobic gram-negative bacilli

Question 2

name drugs that belong to aminoglycosides

Answer 2

1- Gentamycin- amp 10mg/1ml, 80mg/2ml, cream 0.1% 15g
2- Streptomycin- flac 1g
3- Neomycin and Bacitracin- ung dermaticum, aerosol, powder
4- Amikin- amp 250mg/2ml
5- Tobrex- amp 80mg/2ml, collyr 0.3% 5ml
6- Kanamycin- flac 1g

Question 3

pharmacokinetics of aminoglycosides

Answer 3

• A- must be given parenterally (except neomycin), because highly polar and no absorption after oral administration
• D- tissue conc may be subtheraputic and penetration into body fluids is variable
  
  • Extracellular
  • Dont cross BBB but they can cross the placental barrier
• M- not metabolised
• E- unchanged in urine

Question 4

MoA aminoglycosides

Answer 4

=bactericidal!

1- diffuse through porin channels in the outer membrane of susceptible organisms
2- Inside the cell, they bind the 30S ribosomal subunit,
where they interfere with assembly of the functional ribosomal apparatus
and/or
cause the 30S subunit of the completed ribosome to misread the genetic code
- Lead to formation of false proteins

Question 5

SoA of aminoglycosides

Answer 5

broad

Question 6

therapeutic uses of aminoglycosides

Answer 6

1- used in thetreatment of aerobic gram-negative bacilli infections
2 - Complicated urinary tract infections
3- Pneumonia and upper respiratory tract infections.
4 - Endocarditis
5 - Sepsis
6 - Skin and soft tissue infections1

Question 7

contraindications of aminoglycosides

Answer 7

1- Pregnancy and breast feeding
2- Patients with MG
3- Anaerobic infections
4- Hypersensitivity

Question 8

ADRs of aminoglycosides

Answer 8

1- Ototoxicity
2- Nephrotoxicity
3- Neuromuscular reactions

Question 9

drug interactions of aminoglycosides

Answer 9

1 - Don’t take aminoglycosides by mouth or intravenously if you’re already taking:Theracrys (BCG live intravesical)Vistide (cidofovir)Zanosar (streptozocin)
2- With cephalosporins 1st generation – increased nephrotoxicity
3- With Furosemide – increased toxicities; in vitro incompatibility with beta lactams
4- Amphotericin B may decrease the excretion rate of Gentamicin which can result in higher serum levels
5- Ampicillin may decrease the excretion rate of Gentamicin which could result in a higher serum level

Question 10

Resistance to aminoglycosides occurs via

Answer 10

1) efflux pumps,
2)decreased uptake,and/or
3)modification and inactivation by plasmid- associated synthesis of enzymes.