Anti Mycobacterial drugs
Q1. Pyridoxine deficiency is caused due to which of the following
drugs?
- rifampin
- ethionamide
- isoniazid
- para-aminosalicyclic acid
Answer- 3
Isoniazid usage especially in
alcoholics, diabetes, malnutrition and uremia can lead to pyridoxine deficiency
and hence its symptoms such as neuropathy.
Q2. Which of the following
drugs inhibit DNA dependant RNA polymerase ?
- isoniazid
- pyrizinamide
- ethambutol
- rifampin
Answer- 4
Q3. Rahul AIDS and
has acquired mycobacterium avium complex(MAC). Which of the following
medication shouldn’t be dispensed to him along with reverse transcriptase
inhibitor?
1. isoniazid
2. rifampin
3. ethionamide
4. ciprofloxacin
Answer-2
MAC is an opportunistic infection
occurring mostly in immunocompromised patients such as HIV. Rifampin decreases
activity of most reverse transcriptase inhibitors. It also causes contraceptive
failure
Q4. Which of the following metabolite of isoniazid causes
hepatotoxicity?
1. n-
acetyl isoniazid
2. isonicotinic
acid
3. acetyl
hydrazine
4. diacetyl
hydrazine
Answer-3
Q5. Discolouration of skin, sclera, tears etc can occur on prolonged
use of which anti mycobacterial drug?
1. rifampin
2. clofazimine
3. capreomycin
4. dapsone
Answer- both 1and 2. Both
the drugs are dyes
Q6. The action of which of the following
anti mycobacterial drug is dependant on acidic pH?
1. pyrizinamide
2. isoniazid
3. dapsone
4. clofazimine
Answer- 1. Pyrazinamide diffuses into M. tuberculosis, where the
enzyme pyrazinamidase converts pyrazinamide to
the active form pyrazinoic acid. Under acidic conditions, the
pyrazinoic acid that slowly leaks out converts to the protonated conjugate
acid, which is thought to diffuse easily back into the bacilli and accumulate.
The net effect is that more pyrazinoic acid accumulates inside the bacillus at
acid pH than at neutral pH
