Antimicrobial chemotherapy - side effects and toxicity Flashcards
What group of drugs are most commonly associated with allergic reactions
B-lactams
What are the two forms of hypersensitivity
immediate
delayed
What is an immediate hypersensitivity and what is it mediated by
Anaphylactic shock mediated by IgE
What is the mechanisms of a delayed hypersensitivity
immune complex or cell mediated
What are the characterisations of delayed hypersensitivity
Drug rashes - restricted to the skin
Drug fever
serum sickness
What are common gastrointestinal side effects associated with antimicrobial use
Nausea and vomiting
What is an important side effect infection in antibiotic therapy
C.diff
What side effect is associated with c.diff toxins
CDAD - diarrhoea
or an CDI infection psudomembranous colitis
How does C.diff infection arise in antibiotic therapy
carried in the GI tract and overgrows normal flora during antibiotic therapy and produce toxins
How is C.diff toxin detected
detection of toxin in stool by an enzyme immunoassay
What is the treatment of a c.diff infection
oral metronidazole or vanomycin
other antimicrobial treatment is discontinued
Antimicrobials cause side effect of thrush how
As suppress normal flora allowing overgrowth of yeast candida albicans
What is the range of side effects of liver toxicity
elevated liver enzymes
severe hepatitis
What drugs can cause hepatotoxicity
Tertracycline
flucloxacillin
What groups of antibiotics cause nephrotoxicity (renal toxicity)
Aminoglycosides ( e.g gentamicin)
or vancomycin
Probably as both are toxic
Both hepatotoxicity and nephrotoxicity are more common
with patients with pre-existing liver/renal diseases
What are the four types of neurological toxicity
ototoxicity -damage to the ear
optic neuropathy - optic nerve damage
encephalopathy and convulsions - brain function
peripheral neuropathy - damaged nerves
What antimicrobials cause ototoxicity
aminoglycosides
or vancomyosin
what antimicrobials cause optic neuropathy
ethambutol - an antituberculous
When does encephalopathy and convulsions occur
high dose penicillin and cephalosporin use
also with aciclovir
what may produce a reversible peripheral neuropathy
metronidazole and nitrofurantonin
also as anti-tuberculous inhibits vitamin 6 inducing peripheral neuropathy
What is heamatological toxicity
toxic effect on bone marrow
What is the different forms of of heamatological toxicity
neutropenia - selective depression of all bone marrow
pancytopenia - un-selective depression of all bone marrow elements
How does co-trimoxazole cause megaloblastic anaemia producing large bone marrow
As acts as a competitive inhibitor to folic acid
and the folic deficiency affects the bone marrow
antimicrobials should only be used when and in what form
used when indicated
at minimum dose at the duration necessary to achieve efficacy
What are the susceptible groups of antimicrobial therapy
extreme ages
pregnant women
patients with liver or renal insuffiency
What does it mean when antibiotics have a low therapeutic margin
difference between an effective and a toxic dose is small
Why should antibiotics with a low therapeutic margin be monitored
to ensure maximal efficacy and minimal toxicity
