Penicillin - broad spectrum

Question 1

What type of spectrum of activity do amoxicillin and co-amoxiclav have?

Answer 1

broad spectrum - against a wide range of Gram(+) and Gram(-) cocci and bacilli (rods)

however, are inactivated by bacterial penicillinase (leading to resistance)

Question 2

Indications of Amoxicillin

Answer 2

Amoxicillin

1. Otitis Media
2. H.pylori = combined with PPI + Metronidazole or Clarithromycin
3. uncomplicated CAP
4. Sinusitis
5. UTIs

Question 3

Indications of Co-Amoxiclav

Answer 3

Severe, resistant, hospital-acquired infections:
· respiratory tract infections 
· genitourinary and adbominal infection 
· cellulitis 
· bone and joint infections

Question 4

Penicillin MOA ?

Answer 4

SUMMARY: Interfere cell wall peptidoglycan cross-linking, this reduces osmotic control resulting in cell lysis (ultimately death).

Penicillins contain a β-lactam ring, which is responsible for their bactericidal activity.

1. Penicillin inhibits the enzymes responsible for cross-linking peptidoglycans in bacterial cell walls.
2. weakens cell walls = uncontrolled entry of water into bacteria = cell swelling, lysis and death.

Question 5

Side effects of Amoxicillin/Co-Amoxiclav

Answer 5

1. GI upset: diahorroea , nausea (most common)
2. Penicillin allergy: Skin rash , Anaphylactic reaction
3. Acute liver Injury: cholestatic jaundice or hepatitis

Question 6

Amoxicillin and Co-Amoxiclav - Contraindicated in patients with..

Answer 6

Contraindication
1. DO NOT USE: History of PENICILLIN ALLERGY.

Warnings
Use with caution in:
2. Those at risk of C.difficile infection: people in hospital, elderly or those with a Hx of penicillin-associated liver injury.

3. Severe renal impairment

Question 7

Amoxicillin and Co-Amoxiclav- Interactions

Answer 7

WARFARIN

Broad-spectrum penicillins can enhance anticoagulation effect Warfarin.

Question 8

Other than penicillin allergy, what is an adverse effect that occurs less fequently with Amoxicillin/Co-Amoxiclav and antipseudomonal penicillin but can be more severe if it occurs?

Answer 8

Antibiotic-associated colitis (less frequent, more severe) - can accelerate into colonic perforation +/- death

Question 9

Amoxicillin and Co-Amoxiclav- used with caution in patients with…

Answer 9

1. Risk of C.difficile infection: those hospitalised, elderly or those with a Hx of penicillin-associated liver injury.
2. Severe renal impairment

Question 10

What type of pencillin is and what spectrum of activity does piperacillin and tazobactam have?

Answer 10

Antipseudomonal penicillin

Broad spectrum

Question 11

Indications for Antipseudomonal penicillin?

Answer 11

reserved for severe infections - especially in the case of antibiotic resistance and in patients who are immunocompromsied - can treat:

1) Lower respiratory tract infections
2) UTI
3) Intraabdominal sepsis
4) skin and soft tissue infections

Question 12

adverse effects for antipseudomonal penicillin

Answer 12

1. GI upset: diahorroea , nausea (most common)
2. Penicillin allergy: Skin rash , Anaphylactic reaction
3. Antibiotic-associated colitis (less frequent, more severe) - can accelerate into colonic perforation +/- death

Question 13

interactions - antipseudomonal penicillin

Answer 13

methotrexate

warfarin