3 Penicillins: Broad-spectrum

Question 1

list the broad spectrum penicillins

Answer 1

Amoxicillin, ampicillin, co-fluampicil, Co-amoxiclav

Question 2

outline the spectrum of activity for broad-spectrum penicillins

Answer 2

1) Gram-positive and Gram-negative cocci and bacilli (rods).
2)inactivated by bacterial penicillinases, and resistance is increasingly prevalent. 7
↳ ( β-lactamase inhibitor clavulanic acid restores activity of the combination (co-amoxiclav) against many amoxicillin-resistant strains)

Question 3

list the common indications for broad spectrum antibiotics

Answer 3

1) uncomplicated CAP, otitis media, sinusitis and urinary tract infections.
2) H.pylori-associated peptic ulcers
3) Co-amoxiclav is a common choice for severe, resistant and hospital-acquired infections, including respiratory tract infection, genitourinary and abdominal infections, cellulitis, and bone and joint infections.

Question 4

List the important side effects caused by broad spectrum penicillins

Answer 4

1) Gastrointestinal (GI) upset . Less frequently, antibiotic-associated colitis occurs
2) Broad-spectrum antibiotics kill normal gut flora, allowing overgrowth of toxin-producing C. difficile. This debilitating colitis can be complicated by colonic perforation and/or death.
3) Acute liver injury (cholestatic jaundice or hepatitis) usually self limiting

Question 5

who should broad spectrum antibiotics be used in caution with?

Answer 5

1) caution in those at risk of C. difficile infection, particularly those in hospital and the elderly
2) History of penicillin-associated liver injury
3) Dose should be reduced in severe renal impairment (risk of crystalluria)

Question 6

what are some of the important interactions with regards to broad spectrum antibiotics?

Answer 6

Broad-spectrum penicillins can enhance the anticoagulant effect of warfarin by killing normal gut flora that synthesise vitamin K.

Question 7

outline the differences between ampicillin and amoxicillin

Answer 7

1) Ampicillin- poor oral absorption which is further affected by presence of food. lots of resistance . Maculopapular rashes commonly occur with this drug
2) amoxicillin absorption not affected by food. Also used to treat lyme disease

Question 8

what is the important safety information regarding co-fluampicil.

A combination of ampicillin with flucloxacillin

Answer 8

1) Hepatic disorders- administration for 2+ and age are risk factors
2) Flucloxacillin should not be used in those with a history of hepatic dysfunction and impairment

Question 9

how many times greater is the risk of acute liver toxicity in those taking co-amoxiclav compared to amoxicillin?

Answer 9

6 times greater chance of liver toxicity with co-amoxiclav

Question 10

which penicillins need to be taken on an empty stomach?

Answer 10

Flucloxacillin, ampicillin, phenoxymethylpenicillin