Antibiotics

Question 1

Gentamicin

Why is gentamicin once daily dose

Answer 1

Concentration dependant killing is more important than time dependant killing+ post drug effect+ risk of toxicity like nephrotoxicity and ototoxicity more likely in prolonged use

Question 2

Why is Gentamicin used in combination with other drug

Answer 2

Gentamicin enters bacteria by passive diffusion vis porin channels and this process is enhanced in the presence of cell wall synthesis inhibitors e.g. vancomycin and penicillin

Question 3

whats gentamicin mechanism of action and how does resistance develop

Answer 3

enters bacteria by passive diffusion via porin channels and causes irreversible inhibition of protein synthesis.
Resistance is due to decreased intracellular accumulation due to defective porin channels
modification of binding site on the ribosomes receptor
enzymatic inactivation by transferases.

Question 4

Chloramphenicol-MOA

Coverage

Adverse effect

Answer 4

Blocks Protein Synthesis binding to Ribosome 50s

Anaerobic and aerobic gram postive and negative but not chlamydia

Bone Marrow Supression
NVD
Newborn gray baby syndrome

Question 5

What is ANTISEPTIC

Answer 5

Disinfectant applied to living tissue decreases number of organism by killing, removing & diluting

Question 6

Chlorhexidine

Answer 6

Antiseptic-Low skin toxicity 
active against bacteria most potent against Gram positive cocci
Contraindicated 
Allergy
Neurosurgery as neural toxicity
Middle ear surgery- SN deafness