ABX: SE

Question 1

Photosensitivity

Answer 1

Fluoroquinoles
Tetracycline
Antifolate
QT FP

pyrazinamide

Question 2

CYP inducer

Answer 2

Phenobaritone
Carbamazepine
Phenitoin
Rifampicin

Question 3

CYP inhibitor

Answer 3

Macrolides (clari, azi)
Fluoroquinolones
Azoles
Isoniazid 
nitrofurantoin also

Question 4

NM blocking agent

Answer 4

Aminoglycoside (tremour, severe resp depression)
Polymyxin (slurred speech, muscle weakness, apnea)
clindamyxin + nm blockers –> potentiate NM blocking (clindamycin can block nm transmission)

PAC NM
PAC MUSCLE

Question 5

Not for pregnancy and breast feeding.
(7)

Why?

Answer 5

1. Metronidazole
2. Chloramphenicol (liver cannot glucuronidate chloramphenicol–> grey baby syndrome)
3. Aminoglycoside (ototoxicity, nephrotoxicity, NM blockade)
4. Tetracycline (bone and teeth)
5. fluoroquinolones (tendonitis)
6. Cotrimoxazole (kernicterus, compete with bilirubin with albumin, so a lot of free unconjugated bilirubin, causing bilirubin-induced brain dysfunction)
7. Nitrofurantoin (G6PD infants - may cause hemolysis, neutrocytopenia, blood dyscrasia)

Question 6

ototoxicity of aminoglycoside

Answer 6

• hearing loss
• vertigo/N/V/affect balance
• reversible/irreversible (if damage cochlear)
• so need constant monitoring for hearing ability and vestibular balance

risk: pt with renal function; vancomycin

Question 7

Nephrotoxicity of Aminoglycoside

Answer 7

Due to uptake into PCT cell, killing PCT cells
Reversible
Gentamicin and amikacin is more nephrotoxic than tobramycin

risk:
- trough conc (>2 for gentamicin, tobramycin) (>10 for amikacin)
- prolonged tx (>10-14days)
- concomittant nephrotoxic agent (amp B, aztreonam, polymyxin, vanco)
- sepsis
- old

Question 8

NM blockade of aminoglycoside

Answer 8

infrequent
Tremor, severe may lead to resp depression
Reversible with Ca gluconate

Risk:

• mysthesia gravis
• hypoCa, hypoMg
• CCB

Question 9

G6PD

Answer 9

Antifolate

Nitrofurantoin

Question 10

Hepatotoxicity

Answer 10

Augmentin: hepatitis, cholestatic jaundice
Ceftriaxone: obstructive biliary toxicity
Tetracycline: liver failure
Macrolides (rare)
Clindamycin (rare)

5-FC (mild and reversible but monitor ALT and AST weekly)

Question 11

C. difficle
What to treat?

Superinfection

Answer 11

1. High risk for C. difficle D:
   3rd gen cephalosporin, fluoroquinolones, clindamycin (C difficle pseudomembranous colitits)
   Moderate risk:
   Penicillin, other cephalosporin, beta-lactam/beta-lactamase

To tx: Vanco, metronidazole

2. Superinfection: tigecycline,

Question 12

4 SE of linezolid

Answer 12

1. Myelosuppression (rbc/plt)
   (thrombocytopenia, anaemia)
   ->2weeks, renal failure/preexisting myelosuppressed/ concomittant drugs/ reversible
2. Inhibit MAO –> causing serotonin syndrome (NE, HA, BP, mental status)
3. peripheral otic nephropathy
4. lactic acidosis

Question 13

Nephrotoxic agent

Answer 13

Aztreonam
Vancomycin
Polymyxin
Aminoglycoside
Antifolate

Question 14

6 SE of antifolate

Answer 14

1. allergy to sulpha
2. bone marrow suppression (rbc/plt) - megaloblastic s anaemia (immunocompromised, pregnant, renal impaired, HD) can take folinic acid
   - hemolysis in g6pd patients and infants
   - thrombocytopenia in high dose
3. Photosensitivity
4. hyperK with higher dose
   - risk: elderly
5. renal toxicity (false increase in Cr, nephrotoxicity, alleRgic nephritis, crystaluria)
6. kernicterus in neonates -premature/low birth weight baby highest risk

SULFA
PHOTO
HYPERK
THROMBO
HEMOLYSIS
MEGALO ANAEMIA

Question 15

Who not to take fluoroquinolones

Answer 15

1. <18yo
2. Elderly (tendonitis, cause arthopathy, risk of hallucination & seizures)
3. Pregnant ladies (tendonitis)
4. DM (changes in glu level)
5. myasthesia gravis pt
6. arrthymia

Question 16

blackbox warning of fluoroquinolones

Answer 16

tendonitis tendon damage for <18yo, >60yo, organ transplant recipicient; receiving cs therapy

Question 17

SE of fluoroquinolones

Answer 17

1. QT prolongation (moxi>levo/cipro)
2. c.difficle d
3. cns
4. tendonitis
5. change in blood glu
6. muscle weakness for myasthenia gravis pt
7. photosensitivity

Q(qt) T(tendonitia)

Question 18

2 significant SE of metronidazole

Answer 18

metallic taste

dry mouth

Question 19

SE of nitrofurantoin

Answer 19

1. brown urine
2. hemolysis neutropenia for g6pd pt
3. pulmonary interstitial fibrosis with chronic use in elderly

Question 20

for an elderly: avoid:

Answer 20

1. fluoroquinolones (tendonitis, seizure, hallucinations, anthropathy)
2. prolonged nitrofurantoin (pul interstitial fibrosis)
3. aminoglycoside (nephrotoxicity due to advance age)
4. Daptomycin (if patient is on statin)
5. antifolate (risk of hyperK with higher dose due to old age)
6. hepatitis (isoniazid, pyrazinamide)
7. visual toxicity (ethambutol)

Question 21

Drugs causing myelosuppression/bone marrow suppression

Answer 21

bone marrow:

1. Penicllin
2. Linzolid (thrombo, anaemia)
   - tx>14days, concomitant med, already myelosupppressed
3. antifolate (- megaloblastic anaemia, hemolysis in g6pd patients and infants, thrombocytopenia in high dose)
4. nitrofurantoin: hemolysis and neutropenia in g6pd
5. Amp B
6. 5-FC monitor WBC and plts weekly

BonniePeniLikesfolate,nitroF

Question 22

Supplement

Answer 22

anti-folate: folinic acid give to pregnant, malnourished, renal impaired, HD pt

Rifampicin: vit K for infant to prevent post partum hemorrhage

Isoniazid: pyridoxine 10mg OD to prevent peripheral neuropathy

Question 23

if u are renally impaired

Answer 23

• seizures for penicillin if u are not dose adjusted
• C/I for amp B
• dose adj for conventional amp B (50%), 5-fc

Question 24

QT prolongation

Answer 24

Macrolides
Fluoroquinolones (Moxi> levo/cipro)

Triazoles