Aminoglycosdes

Question 1

Source

Answer 1

Natural and synthetic

Question 2

Chemistry

Answer 2

Polar (highly ionized and poorly lipid soluble)

Question 3

Absorption

Answer 3

poorly absorbed orally
They may be also given topically as skin ointments,

Question 4

systemic infections

Answer 4

They must be given IM or IV

Question 5

treatment of GIT infections and bowel sterilization.

Answer 5

Oral

Question 6

treatment of respiratory tract infections,

Answer 6

inhalation

Question 7

treatment of meningitis

Answer 7

intra-thecally

Question 8

Streptomycin given

Answer 8

Intra-pleural
→ Intra-peritoneum

Question 9

Distribution

Answer 9

1.Cannot pass BBB even in meningitis
2.Pass placental barrier and may induce fetal deafness.
3 .Minimal plasma protein binding except streptomycin.
4. Concentrated in renal cortex
5. CN8 → deafness “Imbalance (vertigo)

Question 10

Execrations

Answer 10

excreted unchanged in unine

Question 11

Action on bacteria:

Answer 11

Bactericidal (but bacteriostatic on T.B. bacilli)

Question 12

Mechanism of Action

Answer 12

1.Aminoglycosides diffuse into bacterial cell by an active oxygen-dependent
transport (They are inactive against anaerobes)
2. They bind to 30 S ribosomal subunit leading to inhibition of the codon- anticodon
recognition

Question 13

Adverse effects

Answer 13

1. Ototoxicity: given frequently for long periods and with other ototoxic drugs as aspirin
2. Nephrotoxicity
3. Skeletal muscle weakness due to inhibition of acetylcholine release from
   presynaptic area and decreased sensitivity of Nm-receptors in NMJ (curare-like action).

Question 14

Dosage readjustment

Answer 14

Normal dose / serum creatinine

Question 15

Interval readjusment

Answer 15

Creatinine serum x 8

Question 16

Members

Answer 16

1. Streptomycin
2. Gentamicin
3. Tobramycin
4. Neomycin
5. Kanamycin
6. Spectinomycin
7. Paromomycin