Polymyxin

Question 1

What is sourses of drug?

Answer 1

Natural obtained from bacillus polymyxa bacillus colistinus ( colistin E )

Question 2

Chemically ?

Answer 2

Simple peptides

Question 3

We can take it parentally ?

Answer 3

No we can’t there are extremely nephrotoxic if administered parentally , so they are now restricted to topical application only

Question 4

Mode of action ?

Answer 4

Because they are amphipathic agents containing both lipophobic and hydrophilic groups , they interact strongly with phospholipids leading to disruption of bacterial cell membrane and consequently death of the cell

Question 5

Affect in bacteria?

Answer 5

Bactericidal

Question 6

Spectrum ?

Answer 6

Restricted to gram negative bacteria

Question 7

Sensitive bacteria include ?

Answer 7

E.coli 
Salmonella . spp
Shigella .spp
Enterobacter
Klebsella spp
Pasteurella spp

Question 8

Pharmacokinetics ?

Answer 8

Both ( B , E )are absorbed orally , also poorly absorbed from mucous membranes and surface of the large burns

Question 9

Therapeutic uses ?

Answer 9

Uses only in from of oitment , cream , drops ,dusting powders and lotions
1 infection of eye ( conjunctivitis)
2 infections of ear ( external otitis )
3 infections of skins
4 burns ( combined with other sydtemic antibacterials )
5 sensitive infections diarrhea in infants and children ( only oral use ) the action is local on the bowel

Question 10

Adverse reactions ?

Answer 10

1 nephrotoxicity ( extreme leading to stopping of  systemic use ) 
2 hypersensitivity may be detected