Lincosamides

Front 1

MOA of lincoamides:

Back 1

- 50S subunit ribosomal subunit
- inhibit bacterial protein synthesis

Front 2

Drug - Drug Interaction:

Back 2

- Macrolides and chloramphenicol
- Binding of one of the antibiotics to the ribosome may inhibit the interaction of the others.
- May potentiate effects of neuromuscular blockers.

Front 3

Clindamycin: (PO) no worry about food.
Palmitate vs. Phosphate:

Back 3

Clindamycin Palmitate: inactive prodrug

Front 4

Where can lincosamides accumulate:

NOT IN CNS

Back 4

1. polymorph leukocytes
2. alveolar macrophages
3. abscesses

Front 5

Resistance occurs with lincoamides from:

Back 5

- alteration of binding site on the 50S ribosomal unit (methylation).

Front 6

Adverse Effect of lincoamides:

Back 6

1. Diarrhea
2. Pseudomembranous enterocollitis
3. Rashes

Front 7

How does chloramphenicol work?

Back 7

- Works by inhibiting PEPTIDYLTRANSFERASE (of mammalian NOT cytoplasmic)
with binding of new a.a. to nascent polypeptide chain.

Front 8

Chloramphenicol where does it bind?

Back 8

50S ribosomal subunit -- inhibiting bacterial protein synthess.
- BACTERIOSTATIC (increase cidal at higher dose: N. meningitis, H. influenza, S. pneumoniae

Front 9

Chloramphenicol can inhibit:

Back 9

mammalian mitochondrial > cytoplasmic ribo because they resemble bacterial ribo.

Front 10

Resistance to chloramphenicol:

Back 10

CAT inactivates the drug --> acetylated derivative fails to bind to bacterial ribosomes.

Front 11

Chloramphenicol Succinate:

Back 11

- parenteral adm. --> water soluble prodrug.
- distibuted everywhere

Front 12

How is this chloramphenicol excreted?

Back 12

- hepatic metabolism --> inactive drug
- tubular secretion and glomerular filtration.

Front 13

Chloramphenicol adverse reactions:

Back 13

- hypersentivity:
1. Jarish-Herxheimer
2. Macular or Vesicular skin rashes
Gray Baby Syndrome:
1. flaccidity
2. cynaosis
3. shock
4. CV collapse

Front 14

Chloramphenicol MOA for gray baby syndrome:

Back 14

- decreased glucuronide formation
- decreased excretion of unconjugated drug.

Front 15

More A.E. of chloramphenicol

Back 15

- dose - related bone marrow depression: anemia, leukopenia, thrombocytopenia
(REVERSIBLE)

Front 16

Chloramphenicol:
- inhibits microsomal cytochrome p450 .

Back 16

Aplastic anemia leading to fatal pancytopenia
--- due to prolonged therapy, exposure to drug more than once, genetic predisposition.

Front 17

Lincoamides we want to reduce dosage in

Back 17

hepatic and renal
b. fragilis can treat.