Antibiotics

Question 1

MOA of cotrimoxazole

Answer 1

Inhibit folate synthesis in bacteria

Question 2

SE of cotrimoxazole

Answer 2

Topical hypersensitivity (SJS, TEN) & Photosensitivity due to sulfonamide
Folate deficiency with long-term tx

Question 3

Age limit of cotrimoxazole

Answer 3

Tx = 6 weeks
Prophylaxis of UTI = 2 months
Trimethoprim alone –> can use at birth

Question 4

Major coverage of cotrimaxozole

Answer 4

PCP
Stenotrophonmonas
MRSA
ESBL-producing E.coli / Klebsiella

Question 5

Age limit of quinolones

Answer 5

18y/o due to damage to growing bone & cartilage

Question 6

SE of quinolones

Answer 6

Muscle pain
Neuropathy (Tingling in limbs)
QT Prolongation
Mild GI discomfort
Rash

Question 7

Coverage of quinolones

Answer 7

Broad spectrum against Gm + & Gm-

Stenotrophomonas, Mycobacterium

Question 8

Coverage of nitrofurantoin

Answer 8

Both Gm+ & Gm- except pseudomonas
ESBL-producing E.coli
VRE

Question 9

SE of nitrofurantoin

Answer 9

Dizziness
GI disturbances (n/v)
Skin hypersensitivity
Hepatotoxicity
Neuropathy & Haemolytic anaemia in G6PD

Question 10

SE of metronidazole

Answer 10

n/d/ stomatitis with proonged tx

Question 11

Drug-food interaction of metronidazole

Answer 11

Alcohol

• Alcohol increase aldehyde level in colon
• Metronidazole kills anaerobics –> aldehyde-containing aerobic bacteria increase –> “disulfiram-like” effects –> flushing, tachycardia, panic, distress

Question 12

SE of aminoglycosides

Answer 12

Nephrotoxicity
Ototoxicity
Neuromuscular-block

Question 13

Spectrum of linezolid

Answer 13

MRSA, VRE, Mycobacterium

Inactive against Gm-

Question 14

DDI of linezolid

Answer 14

MAOI, SSRI –> serotonin syndrome

Question 15

SE of linezolid

Answer 15

Myelosuppression
Lactic acidosis
Neuropathy (Peripheral & Optic)

Question 16

Age limit of tetracyclines

Answer 16

> 8yo

Question 17

SE of tetracyclines

Answer 17

Tooth discolouration (due to binding to Ca2+)
Bone deformities (due to binding to Ca2+)
Photosensitivity –> skin rash
Renal & hepatic toxicity @high dose
Superinfection (Intestine, vagina)

Question 18

SE of systemic chloramphenicol

Answer 18

Pancytopenia
Grey baby syndrome (high mortality)
- Vomit, shock, cyanosis, hypothermic

Mild SE = hypersensitivity, rash, n/v/d

Question 19

Coverage of chloramphenicol

Answer 19

Broad spectrum of Gm+ & Gm-
- including MRSA
Intrinsically resistant to Pseudomonas

Question 20

SE of clindamycin

Answer 20

Diarrhoea
Skin rash
C.diff colitis