Chart and Notes: Classes of Aminoglycosides, Pharmacology and MCQ for GPAT, NEETPG, Pharmacist and Nursing Exams
Chart: Classes of Aminoglycosides
| Class/Generation | Examples | Route of Administration | Spectrum | Toxicity | Clinical Use |
|---|---|---|---|---|---|
| Natural (1st Gen) | Streptomycin, Neomycin | IM/IV (Streptomycin), topical/oral (Neomycin) | Gram-negative & TB (Streptomycin) | Ototoxicity, nephrotoxicity | TB, plague, bowel sterilization |
| Semi-synthetic | Gentamicin, Tobramycin, Netilmicin | IM/IV | Broad gram-negative | Less toxic than streptomycin | Pseudomonas, sepsis, respiratory infections |
| Extended Spectrum | Amikacin | IM/IV | Resistant gram-negative bacteria | Nephrotoxic, ototoxic | MDR TB, nosocomial infections |
| Others | Kanamycin, Paromomycin | IM/oral/topical | Intestinal amoebiasis, protozoa | Ototoxic, nephrotoxic | Amoebiasis, leishmaniasis |
Key Points:
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Mechanism: Inhibit bacterial protein synthesis by binding to 30S ribosomal subunit.
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Bactericidal, especially against aerobic Gram-negative organisms.
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Ineffective against anaerobes (require oxygen for uptake).
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Major side effects: Ototoxicity (hearing loss) and Nephrotoxicity (renal damage).
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Often combined with β-lactams for synergistic effect.
Multiple Choice Questions (MCQs)
1. What is the mechanism of action of aminoglycosides?
A. Inhibit DNA gyrase
B. Inhibit cell wall synthesis
C. Inhibit 30S ribosomal subunit
D. Disrupt cell membrane
Answer: C
2. Which aminoglycoside is most resistant to enzymatic degradation?
A. Streptomycin
B. Gentamicin
C. Amikacin
D. Neomycin Answer: C
3. Which adverse effect is common with aminoglycoside use?
A. Hepatotoxicity
B. Ototoxicity
C. Hypoglycemia
D. Constipation Answer: B
4. Aminoglycosides are ineffective against which type of bacteria?
A. Gram-positive
B. Gram-negative
C. Anaerobes
D. Mycobacteria Answer: C
5. Neomycin is primarily used for:
A. Treating pneumonia
B. Tuberculosis
C. Bowel sterilization
D. Meningitis Answer: C