Cotrimoxazole

Question 1

What is  Cotrimoxazole

Answer 1

It is a fixed combination of sulphamethoxazole and trimethoprim

Question 2

What is the ratio of Cotrimoxazole

Answer 2

Sulphamethoxazole : trimethoprim
5:1

Question 3

Which enzyme does sulphamethoxazole inhibit

Answer 3

Folate synthetase

Question 4

Which enzyme does trimethoprim inhibit

Answer 4

Folate reductase

Question 5

What are the advantages of using sulphamethoxazole and trimethoprim in combination

Answer 5

1. Individually, both are bacteriostatic with a combination has cidal effects
2. Chances of development of bacterial resistance of greatly Reduced

Question 6

What are the common adverse effects of  Cotrimoxazole

Answer 6

Skin rashes and G.I. disturbances ( nausea, vomiting, glossitis and stomatitis) 

Question 7

What are side effects of Cotrimoxazole

Answer 7

1. Exfoliative dermatitis
2. Erythmea multiforme
3. Steven Johnson syndrome
4. G.I. disturbances skin rashes
5. megaloblastic anaemia (rare)
6. bone marrow suppression
7. leucopenia, neutropenia, thrombocytopenia

Question 8

What are the uses of Cotrimoxazole

Answer 8

1. UTI - Gram-negative organisms such as E. coli, Proteus, enterobacter spp.
2. Bacterial prostatitis
3. bacterial respiratory infection, acute and chronic bronchitis - S. pneumonia and H. influenza
4. Acute maxillary sinusitis and otitis media
5. Bacterial diarrhoea shigella, E. coli, salmonella spp. 
6. Typhoid fever
7. Pneumocystis Jiroveci Infection and prophylaxis
8. Nocardiosis
9. Chancroid