G-M abx Flashcards
What are glycopeptides?
vancomycin, teicoplanin, dalbavancin, telavancin
can ONLY be given parenterally
- reduced absorption with oral intake
What is Red Man Syndrome?
Vancomycin infusion reaction/Vancomycin Flushing Syndrome/Red Man Syndrome
- rate dependent infusion reaction
- intense red rash, itching, chest pain hypotension, flushing
How should vancomycin be dosed? How should it be monitored?
- initial doses should be based on body-weight
- subsequent dose adjustments should be based on serum-vancomycin concentrations
- monitor on the 2nd day of treatment, immediately before the next dose if renal function normal, earlier if renal impairment
What should the trough concentration of vancomycin be?
10–20 mg/litre
- (15–20 mg/litre for pathogens with MIC greater than or equal to 1 mg/litre)
What are the side effects of glycopeptides? What medications should be avoided?
ototoxicity
- cisplatin
- loop diuretics
- vancomycin
- vinca alkaloids
nephrotoxicity
- ARBs/ACEi
- NSAIDs
- metformin
What are red flags associated with vancomycin/glycopeptides?
red man syndrome
severe cutaneous adverse reactions (SCARs) - SJS
blood dyscrasias - agranulocytosis, eosinophilia, neutropenia
cardiogenic shock on rapid IV injection
risk of anaphylactoid reactions at infusion sites - avoid rapid infusion and rotate site
What are the MHRA warnings associated with Linezolid?
optic neuropathy
- if used for more than 28 days
- report symptoms of visual impairment (blurred vision, visual field defect, changes in visual acuity and colour vision)
- monitor regularly if treatment is required for longer than 28 days.
blood disorders
- if used for more than 10-14 days
- if they have myelosuppression, severe renal impairment, using drugs that affect bloods
- monitor with weekly FBCs
What monitoring is needed for linezolid?
weekly FBCs
What are important interactions with linezolid?
avoid consuming large amounts of tyramine-rich foods (such as mature cheese, salami, pickled herring, Bovril®, Oxo®, Marmite® or fermented soya bean extract, and some beers, lagers or wines).
- can cause severe hypertension
adrenaline, pseudoephedrine
- can cause severe hypertension
risk of serotonin syndrome
- SSRIs, Dopaminergics, 5HT-1 agonists (Triptans), TCAs (imipramine), Lithium, MAOIs (isocarboxazid, tranylcypromine)
What are macrolides?
azithromycin (OD), clarithromycin (BD), erythromycin (QDS) (preferred in pregnancy)
are CYP enzyme INHIBITORS
What are side effects associated with macrolides?
hepatotoxicity
ototoxicity
- hearing loss in large doses
gastrointestinal disturbances
QT prolongation
What are the interactions for macrolides?
are CYP enzyme inhibitors
- statins: increased risk of myopathy
- warfarin: increased risk of bleeding
hypokalaemia
- avoid diuretics, steroids, salbutamol, theophylline
increased risk of QT prolongation
- antiarrhythmics: amiodarone
- antibiotics: azoles, quinolones
- antipsychotics
- antidepressants: SSRIs, TCAs
- diuretics
- antiemetics: ondansetron
- lithium
What are the MHRA warnings for erythromycin?
increased cardiac risks: QT prolongation
- avoid in patients with history of QT prolongation
interaction with rivaroxaban
- increased bleeding risk
increased risk of infantile hypertrophic pyloric stenosis
- vomiting or irritability with feeding
What are side effects associated with metronidazole?
taste disturbance - metallic taste and furred tongue
nausea and vomiting - take with or after food
dry mouth
What is the counselling point for metronidazole?
must not drink alcohol whilst on this medication
- avoid DURING and 48 hours after stopping
- disulfiram like effect: nausea, vomiting, flushing
What are interactions with metronidazole?
increases anticoagulant effect
- warfarin, acenocoumarol
What are the narrow spectrum antibiotics? PGTLC
penicillins (penicillin V and G)
glycopeptides
trimethoprim
linezolid
clindamycin
What are the broad spectrum antibiotics? CAPTN MCQ
chloramphenicol
aminoglycosides
penicillins (amoxicillina and ampicillin)
tetracycline
nitrofurantoin
macrolides
cephalosporins
quinolones
Which antibiotics are nephrotoxic?
nitrofurantoin
aminoglycosides
glycopeptides
tetracyclines
trimethoprim
Which antibiotics are hepatotoxic?
macrolides
flucloxacillin
co-amoxiclav
RIP
- rifampicin, isoniazid, pyrazinamide
What is the treatment for
- staphylococcus
- MRSA
- streptococcus
- anaerobic bacteria
- pseudomonas aeuroginosa
- staphylococcus: flucloxacillin
- MRSA: vancomycin
- streptococcus: benzylpenicillin, phenoxymethylpenicillin
- anaerobic bacteria: metronidazole
- pseudomonas aeuroginosa: gentamicin
