Pharmacology

Question 1

Systemic use Aminoglycosides.

Remember ANGST

Answer 1

• **Amikacin
• Gentamicin
• Netilmicin
• Streptomycin
• Tobramycin**

Question 2

Local Use Aminoglycosides

Remember NGT K

Answer 2

• **Neomycin
• Gentamicin
• Kanamycin
• Tobramycin**

Question 3

Oral Use Aminoglycosides

Remember KhaNa

Answer 3

• Neomycin
• Kanamycin

Question 4

Mechanism of Action of Aminoglycosides

Answer 4

These drugs bind to the 30s ribosomal subunit and inhibit protein synthesis by;
- Blocking the initiation complex and translocation step of peptide formation (bacteriostatic action).
- Misreading of genetic code i.e. miscoding or insertion of incorrect amino acids in the nascent peptide chain which results in non-functional proteins or premature termination of protein synthesis (bacteriocidal action).

Question 5

Aminoglycosides are effective against _________.

Answer 5

Aerobic gram-negative species.
* They are used in combination with a β- lactam antibiotic to extend the coverage and include gram positive organisms as well.

Question 6

What are the mechanisms which lead to resistance towards Aminoglycosides

Answer 6

• Production of enzyme transferases that inactivate the aminoglycoside.
• Impaired entry of aminoglycoside into the cell.
• The receptor protein on the 30s ribosomal subunit may be altered or deleted.

Question 7

Uses of Aminoglycosides

Answer 7

• Pneumonia
• Endocarditis
• Pelvic inflammatory disease
• UTI
• Bacteremia, sepsis
• Topical given for infected wounds, burns, skin lesions

Question 8

Adverse effects of Aminoglycosides

Answer 8

Nephrotoxicity (Neomycin, Tobramycin and Gentamycin)
Ototoxicity (Neomycin, Kanamycin and Amikacin) -> Cochlear damage
Neuromuscular paralysis
Allergic reaction: fever, skin rash and other allergic manifestations may occur.
Streptomycin and Gentamycin: Vestibulotoxic

Question 9

Contraindication of Aminoglycosides

Answer 9

Pregnancy; it may cause deafness of the newborn.

Question 10

Neomycin uses

Answer 10

TOPICAL ADMINISTRATION:
- Used for infected wounds or injected into joints and pleural cavity or abscess cavity.
ORAL ADMINISTRATION:
- In preparation for elective bowel surgery one gram of neomycin given orally every 6-8 hrly for 1-2 days often combine with erythromycin. This reduces the aerobic bowel flora & thus reduces the chance of post operative infections