Nucleic Acid Inhibitors

Question 1

Nucleic acid synthesis inhibitors are

Answer 1

Sulfonamide
Trimethoprim
Rifampicin

Question 2

M/A of sulfonamide

Answer 2

Sulfonamide ===> inhibit para-amino-benzoic acid ==> no folic acid synthesis ==> no bacterial RNA or DNA synthesis ===> No bacterial growth ===> antimicrobial action

Question 3

A/E of Sulfonamide

Answer 3

1) Hypersensitivity = rash , urticaria , fever , Steven Johnson syndrome
2) Aplastic anaemia
3) Megaloblastic anaemia
4) granulocytopenia
5) glossitis
6)stomatitis
7) headache
8) crystaluria
9)hematuria
10) Anuria
11) hepatitis
12) krenictreus

Question 4

S/n sulfonamide

Answer 4

It is the structural analogue of PABA
It inhibits folic acid synthesis
Narrow spectrum
Bacteriostatic
Has diuretic , hypoglycemic and anti eprotic action

Question 5

Classification of Sulfonamide

Answer 5

ACC to duration of action
Acc to site of action

Question 6

Acc to duration of action

Answer 6

SHORT ACTING ==> Sulfisoxazole , sulfamethizole , sulfacytine

INTERMEDIATE ACTING==> Sulfadiazine, sulfamethoxazole , sulfapyridine

LONG ACTING ==> Sulfasalazine , Sulfadozine , silver sulfadiazine

Question 7

Acc to site of action

Answer 7

SYSTEMIC = sulfasalazine , sufladizaine , sulfamethoxazole

LOCAL = silver sulfadiazine , sodium sulfacetamide, mafenide acetate

Question 8

Clinical uses of Sulfonamide

Answer 8

Pneumonia
Sinusitis
Bronchitis
Toxoplasmosis
Malaria
UTI
Enteritis
Irritable bowel syndrome
Trachoma
Burn
Wound infection Genital tract

Question 9

Clinical uses of tropical Sulfonamide

Answer 9

Burn
Wound infection
Pressure ulcer
Bacterial conjunctivitis

Question 10

Co- trimoxazole S/N

Answer 10

Co for combination
Tri for trimethoprim
Moxazole for sulfamethoxazole
So combinely it is a combination of trimethoprim and sulfamethoxazole
Doses are = sulfamethoxazole = 400mg // trimethoprim = 80mg
Dose- 5:1
Individually they are bacteriostatic but combinely they are bacteriocidal
Combinely broad spectrum activity
Long duration of action
Having synergistic effects

Question 11

M/A of co trimoxazole

Answer 11

Sulfamethoxazole inhibit FOLIC ACID SYNTHESIS FROM PABA by inhibition of DIHYDROPTEROATE SYNTHASE
Trimethoprim inhibit DNA synthesis by inhibitor of DIHYROFOLATE REDUCTASE ENZYME so lysis of bacteria and antibacterial action

Question 12

Uses of co trimoxazole

Answer 12

Pneumonia
Bronchitis
Sinusitis
Tonsillitis
Lung abscess
Enteric fever
UTI
Prostatitis
Chancroid
Wound infection
Cellulitis
Carbuncle

Question 13

Contraindications of co trimoxazole

Answer 13

Pregnancy
Lactating mother
Children less than 15 days
Renal failure
Hepatitis
Blood disorder