Penicillins Flashcards
What are the classes of antibiotics?
- Penicillins
- Cephalosporins
- Carbapanems
- Macrolides
- Aminoglycosides
- Glycopeptides
- Tetracyclines
- Quinolones
Give 6 examples of penicillins?
- Amoxicillin
- Ampicillin
- Flucloxacillin
- Benzylpenicillin
- Phenoxymethylpenicillin (penicillin V)
- Piperacillin
What is it important to remember when prescribing co-amoxiclav?
That it contains a penicillin, and so cannot be given to penicillin-allergic patient
What is the mechanism of action of penicillins?
Inhibits cross-linking of peptide chains in the peptidoglycan bacterial cell wall, resulting in lysis of the weakened bacterial cell wall and subsequent cell death
What is meant by broad spectrum penicillins?
Effective in treating gram +ve and gram -ve bacteria, depending on indication
Why is important to avoid the over-prescribing of antibiotics?
Because the rise of antibiotic-resistant bacteria is a serious challenge worldwide
What are the potential routes of delivery of penicillins?
- PO
- IV
- IM
What are the indications for penicillins?
- Respiratory tract infection
- Otitis media
- Urinary tract infection
- Cellulitis
- Bacterial meningitis
- ENT infections
- Prophylaxis
What penicillin can be used in respiratory tract infections?
- Amoxicillin
- Ampicillin
What penicillin can be used in UTIs?
- Amoxicillin
- Ampicillin
What penicillin can be used in otitis media?
- Amoxicillin
- Ampicillin
What antibiotic can be used in cellulitis?
Flucloxacillin
What antibiotic can be used in bacterial meningitis?
Benzylpenicillin
What antibiotic can be used in ENT infections?
Phenoxymethylpenicillin
When might extended spectrum penicillins be required?
- Severe infections
- Pseudomonas
Give an example of an extended spectrum penicillin?
Piperacillin
Who might require prophylactic penicillin?
Splenectomy patients
What antibiotic prophylaxis are splenectomy patients given?
Usually low-dose penicillin
In addition to antibiotic prophylaxis, what else will splenectomy patients be given?
Further vaccinations, including the annual flu jab
In whom are penicillins contraindicated?
In patients with hypersensitivity reaction to penicillin
What is it important do when a patient reports that they are hypersensitive to penicillin?
Clarify details of allergic reaction to confirm that this is a true penicillin allergy
Other than penicillins, what antibiotics should patients with immediate hypersensitivity reactions to penicillins react to?
Cephalosporins and other beta-lactam antibiotics, therefore should not receive these antibiotics
What monitoring may be required when giving penicillins?
- WCC
- CRP
- Patients clinical state
What needs to be done if starting a patient on IV antibiotics?
This route should be reviewed within 48 hours of starting treatment
What might interact with penicillin?
- Warfarin
- Methotrexate
What effect might penicillins when given with warfarin?
May increase INR
(bleeding time)
What effect might penicillins have when given with methotrexate?
Increase risk of toxicity
What are the common side effects of penicillins?
- Antibiotic associated diarrhoea
- Hypersensitivity reactions
What are the less common side effects of penicillins?
- CNS toxicity
- False positive urinary glucose
What patient counselling needs to be given with penicillins?
- Complete antibiotic course
- Take before food
- Risks and signs of allergic reaction/angiodema
- Important drug interactions
Why is it important to counsel the patient about completing their antibiotic course with penicillin?
Failure to complete course may result in antibiotic resistance, making infections by the pathogen harder to treat in the future
What penicillins should be taken on an empty stomach?
- Flucloxacillin
- Phenoxylmethylpenicillin
How can you ensure the patient knows how to take their penicillin?
Advice them to read the instruction leaflet with their medication for further instructions on its use
What signs of allergic reaction to penicillin should patients be made aware of?
- Swelling of face, eyes, lips, or tongue
- Breathing difficulties
What should patients be advised to do if they develop the symptoms of an allergic reaction to penicillin?
Call an ambulance
What may be required as a result of penicillins potentially increasing INR?
May be necessary to get INR checked more regularly during antibiotic course
