Antibiotics and friends Flashcards
What are common indications of needing flucloxicillin?
staphalococcus infection - cellulitis, endocarditis, osteomyelitis, septic arthritis
What is the mechanism of action of flucloxicillin?
they weaken cell walls leading to swelling and death
What are some adverse reactions of flucloxicillin?
GI upset, liver toxicity
allergy - rash, anaphylaxis
What are some warnings of flucloxicillin?
caution in liver or renal impairment
Caution if penicillin allergy or flucloxicillin hepatotoxicity
What are some interactions of flucloxicillin?
increase risk of methotrexate toxicity - fluclox decreases renal excretion of methotrexate
What are cephalosporins and carbapenems and give some examples?
broad spectrum pencillin based antibiotics
e.g. cefotaxime, meropenem
What are indications of cephalosporins and carbapenems?
urinary tract or respiratory infections
very severe or complicated infections
e.g. cefotaxime and meningitis
What is mechanism of action of cephalosporins and carbapenems?
B lactam ring impacts cell wall = lysis, death
What are interactions of cephalosporins and carbapenems?
enhance anticoagulation of warfarin
increase nephrotoxicity of aminoglycosides
reduce plasma concentration of valporate
What are adverse effects of cephalosorins and carbapenems?
GI upset
hypersensitivity
neurotoxicity
What are warnings of cephalosporins and carbapenems?
more likely to have C, diff
allegy to penicillins
epilepsy
renal impairment
What are the two broad spectrum penicillins and their uses?
amoxicillin - CAP, otitis media, UTI, h. pylori GI problems
co-amoxiclav - more complicated hospital acquired infections
What is mechanism of action of broad spectrum penicillins?
damage cell wall = cell lysis
What are adverse reactions of broad spectrum antibiotics?
GI upset
allergy - skin rash, anaphylaxis
acute liver injury, jaundice
What are some warnings of broad spectrum penicillins?
history of allergy or c. diff
penicillin associated liver injury, renal injury
What are interactions of broad spectrum penicillins?
increase anticoagulation of warfarin
What are examples of quinolones and what are they?
non-penicillin broad spectrum antibiotics (esp. gram - bacteria)
ciprofloxacin, levofloxacin, moxifloxacin
What are indications for using quinolones?
used 2nd/3rd line due to c. diff risk and liklihood to gain resistance
LRTI, severe gastroenteritis, UTI
What is the mechanism of action of quinolones?
they inhibit DNA synthesis
bacteria gain resistance to quinolones quickly
What are some adverse reactions of quinolones?
GI upset (c. diff infection) resistance quickly prolong QT interval - arrthymias reduce seizure threshold tendon inflammation and rupture
What are some warnings for quinolones?
used in caution in children and where QT prolongation or lowering seizure threshold would be dangerous
What are some interactions with quinolones?
drugs containing divalent cautions - calcium, antacids
ciprofloxacin inhibits CYP enzymes
co-prescription with NSAIDs further increases risk of seizures
co-prescription with prednisilone further increases risk of tendon rupture
prescribe with caution with other drugs that prolong QT interval e.g. amiodarone, antipsychotics, SSRIs
What are indications of metronidazole?
anaerobic or protozoa infections e.g. surgical or gynae infection, C. diff, oral infections
What is mechanism of action of metronidazole?
DNA degradation and cell death
What are adverse reactions of metronidazole?
GI upset hypersensitivity peripheral and optic neuropathy seizures encephalopathy
What are warnings with metronidazole?
severe liver disease
alcohol
What are interactions with metronidazole?
CYP inducers - reduce plasma conc.
inhibit CYP enzymes - reduce warfarin metabolism
increase risk of lithium toxicity
What are examples of aminoglycosides and what do they act on?
gentamicin, amikacin, neomycin
act on gram negative aerobic bacteria
What are common indications of aminoglycosides?
sepsis, UTI, pyelonephritis, endocarditis
skin, eye, ear infections
What is the mechanism of action of aminoglycosides?
bind irreversibly to bacterial ribosomes
What are adverse effects of aminoglycosides?
nephrotoxicity and ototoxicity
What are warnings of aminoglycosides?
neonates, elderly
renal impairment
myasthenia gravis
What are important interactions of aminoglycosides?
ototoxicity more likely in loop diuretics, vancomycin
nephrotoxicity more likely with ciclosporin, chemo, cephalosporins, vancomycin
What is gentamicin dose determined by?
ideal body weight
if 20% heavier, use adjusted body weight
What is important monitoring with gentamicin?
concentration
renal function
How long should vancomycin be transfused over?
infuse over 1 hour minimum
What are some examples of antifungals?
nystatin, clotrimazole, fluconazole
What are some adverse effects of antifungals?
topical - skin irritation
systemic - GI upset, headache, hepatitis, QT prolongation, hypersensitivity
What are warnings and interactions with antifungals?
caution with liver disease and renal impairment, don’t use in pregnancy
fluconazole inhibits CYP
don’t use with other drugs that prolong QT interval
What is a common antiviral drug, what is it used for and how does it work?
aciclovir
used to treat the herpes virus
inhibits herpes-specific DNA polymerase
What are some adverse effects of aciclovir?
headache, dizziness, GI disturbance, skin rash
acute renal failure
What are some warnings and adverse reactions of aciclovir?
caution in pregnant women, breastfeeding and kidney problems
no important interactions
What is cloramphenicol and what is it used for?
is a braod spectrum antibiotic used as eye drops (bacterial conjuncitivitis) or ear drops (otitis externa)
What are some adverse reactions of chloramphenicol?
topical - stinging, itching burning
systemic (rare use) - grey baby syndrome (circulatory collapse in neonates), bone marrow suppression, aplastic anaemia, optic and peripheral neuritis
What are some warnings or interactions with chloramphenicol?
hypersensitivity, bone marrow disorders
don’t give in third trimester, breastfeeding or babies <2 years
caution in hepatic impairment
no interactions topically
What are some examples of a macrolides and what are they used for?
clarithromycin, erythromycin, azithromycin
used to treat respiratory, skin and soft tissue infections
also eradicate helicobacter
What are some adverse effects of macrolides?
nausea, vomiting, abdo pain, diarrheoa
antibiotic-associated colitis
prolong QT interval
otoxocity
What are warnings and important interactions of macrolides?
hypersensitivity
hepatic or renal impairment
inhibit CYP
don’t prescribe with other drugs that prolong QT
What is nitrofurantoin used for?
treatment or prophylaxis of UTI
What are adverse reactions of nitrofurantoin?
GI upset, hypersensitivity, urine yellow or brown, chronic pulmonary disease, heptatits, perihperal neuropathy
What are warnings and interactions of nitrofurantoin?
pregnant women, babies under 3 months, renal impairment
no interactions
What are some names of artifical tears and what are they used for?
hypromellose, carbomers, liquid and white soft paraffin
any dry eye conditions
What are some SE of artificial tears?
stinging and blurring of vision
allergic reaction
What are some warnings and interactions with artificial tears?
NONE
What are the names of some penicillins and what are they used for?
benzylpenicillin, phenoxymethylpenicillin
tonsilitis, pneumonia, endocarditis, meningitis, gangrene
What are some adverse effects of penicillins?
allergy, neurologiccal toxicity
What are warnings or important interactions of penicillins?
renal impairment, penicillin allergy
penicillins reduce extretion of methotrexate
