Drugs for osteomyelitis

Question 1

Antibiotics for staph aureus

Answer 1

• Ceftriaxone

- Vancomycin

Question 2

Vancomycin is reserved for serious infections like

Answer 2

MRSA

Question 3

Drugs for Mycobacterium tuberculosis

Answer 3

RIPES

Question 4

Intensive phase for Mycobacterium tuberculosis

Answer 4

2 months of RIPE DAILY, supplement with Vit B6

Question 5

Continuous phase for Mycobacterium tuberculosis

Answer 5

6 months of rifampicin & isoniazid, 2-3x a week

Question 6

MOA of rifampicin

Answer 6

Inhibit RNA synthesis→ bind to Beta subunit of RNA polymerase

Question 7

Side effects of rifampicin

Answer 7

Orange discolouration of body fluids 
GI disturbance (take w food) 
Pseudomembranous colitis 
Acute renal failure 
Hepatotoxicity 
Hyperuricemia (uric crystals) 
Blood dyscrasia 
Nausea, vomiting
Epigastric pain
Anorexia
Skin eruption and fever

Question 8

For patients with HIV, what drug to replace rifampicin?

Answer 8

rifabutin

Question 9

What should we monitor when giving rifampicin?

Answer 9

Liver function

Question 10

Do not give rifampicin w ________

Answer 10

warfarin/ methadone

Question 11

MOA of isoniazid

Answer 11

Inhibit mycolic acid (essential component of mycobacterium cell walls)

Question 12

Side effects of isoniazid

Answer 12

Peripheral neuropathy
Optic neuritis
Blood dyscrasias
Pellagra- severe B3 def

Question 13

Pyrazinamide MOA

Answer 13

Inhibit bacteria cell membrane & transport function

Active pyrazinoic acid→ kills semi dormant vacili in acidic pH env not killed by other TB drugs

Question 14

Side effects of pyrazinamide

Answer 14

Fatal haemoptysis (coughing blood) 
Haemolytic anaemia 
GI disturbance (take w food) 
Photosensitivity (avoid sunlight)
Liver toxicity
Hyperuricemia → Gouty arthritis

Question 15

What should we monitor when giving pyrazinamide?

Answer 15

Monitor uric acid lvl, liver, kidney function

Question 16

MOA of ethambutol

Answer 16

Inhibit arabinogalactin (cell wall) synthesis

↓ Al salts absorption so take after 2 hrs

Question 17

Side effects of ethambutol

Answer 17

Anaphylaxis
Optic neuritis
Nausea, vomiting, headache
Asymptomatic hyperuricemia

Question 18

What should we monitor when giving ethambutol?

Answer 18

Need to check visual acuity to assess toxicity

If pt is unable to perform an eye test (<8YO/ red green colour blind), sub w streptomycin

Question 19

For all RIPE, contraindication:

Answer 19

NO ALCOHOL

Question 20

MOA of ceftriaxone

Answer 20

Inhibit transpeptidation (build vertically)→ prevent bacteria cell wall synthesis

Question 21

Side effects of ceftriaxone

Answer 21

Well tolerated
Rash, diarrhoea most common
Thrombophlebitis
Severe hypersensitivity 
Swelling of face, difficult breathing:  can develop into Steven Johnson syndrome 
Anaphylaxis

Question 22

MOA of vancomycin

Answer 22

Binds to D-ala peptides, inhibit cross-linking of peptidoglycan side chains → inhibit cell wall synthesis

Question 23

Side effects of vancomycin

Answer 23

Most common: thrombophlebitis- pain, inflammation at infusion site 
Red man’s syndrome (flushing/red)
Anaphylaxis 
Nephrotoxicity 
Ototoxicity