AM revision Flashcards
What mediates drug allergies?
immediate hypersensitivity - IgE mediated
Delayed Hypesensitivity - Cell or immunecomplex mediated
Symptoms of Immediate hypersensitivity?
- LAryngeal Oedema
- Shock
- Itching
- Urticaria (hives)
- Voming/nausea
- Wheezing
Symptoms of delayed hypersensitivity:
- Erythema Nodosum
- Drug Rash
- Drug fever
- Serum sickness
What antivirals need constatn blood conc. monitoring?
Zidovudine for HIV
Ganciclovir for CMV
What is stevens-johnson syndrome?
A form of Delayed hypersensitivity
Not just skin but mucous membranes
What am is associated with stevens-johnson?
Sulphonamides
What is thrush & what am causes it?
Oral or vaginal candidiasis
Caused by Broad spec. penicillin/cephalosporins
What drugs commonly cause hepatotoxicity?
Tetracylcines
Rifampicin
Flucloxicillin
Isonizaid (TB)
What drugs commonly cause convulsions & encephalopathy?
PEnicillin
Cephalosporin
Acyclovir
What drugs commonly cause ototoxicity?
Aminoglycosides
Vancomycin
What drugs cause peripheral neuropathy?
Isoniazid
Metronidazole
Nitrofurantoin
How does isoniazid cause peripheral neuropathy?
Competetive inhibition of Vitamin B6 (pyridoxine)
What is pancytopenia?
Depression of all marrow produced cell lines (unselective depression)
What causes selective depression of platelets?
Linezolid
How does co-trimoxazole produce a haematological side effect?
Co-trimoxazole inhibits folic acid synthesis
- > Folate deficiency
- > Megaloblastic anaemia
What is co-trimoxazole?
Trimethoprim
Sulphamethoxazole
When would you use co-trimoxazole over cephalosporins and why?
For chest infections as its less likely to cause a CDI
How do glycopeptides work?
Glycopeptides inhibit peptidoglycan precurosor production
How do Beta-lactams work?
Bind to PBP
- > Inhibits carb cross chain linkage
- > no peptidoglycan formed
- > cell killed by autolytic enzymes
Another name for benzyl penicillin?
PEnicillin G
What would you use on a gram +ve infection if someone was alleric to penicillin?
Macrolides particularly erythromycin & clarythromicin
What do you use levofloxacin for?
A chest infection
Its much better than older quinalones for gram +ves
Why are glycopeptides given parenterally?
They arnt absorbed in the gut
What do mutagenic drugs do?
Mutate foetal chromosomes
What do teratogenic drugs do?
Theyre associated with congenital abnormilities
How are antimicrobials used for prophylaxis?
- Pre-op to prevent infection
- Post-exposure to a highly communicable disese
What antibiotics need constand monitoring?
Vancomycin
Gentamicin
Example of synergy with AMs?
Penicillin & gentamicin undergoe snergy when treating Streptococcal infections
When would you use combination therapy?
- When theres a mixed infection
- When the two drugs have a synergistic effect
- When you want to limit resistance to any one agent
What drug causes abnormal cartilage development in kids?
Ciprofloxacin
Define inherent resistance?
All strains of a species are resistant
Usually because the drug cant penetrate the cell wall
E.g. VRE
Define acquired resistance?
Sometimes by spontatnoues mutation but normally transfer of genes through plasmids or transposons.
Only some of the strains are resistant
E.g. 30% of E.Coli strains are resistant to Ampicillin
How do we combat B-lactamases?
- None B-lactams
- Modify the B-lactam R1 side chain so its not recognised
- Mix it with a B-lactamase inhibitor
What is an R1 modified penicillin?
Flucloxacillin
What is a mix of a B-Lactam & a B-lactamase inhibiotr?
Co-Amoxiclav is amoxicillin & calvulanic acid.
What is ESBL?
Exteneded spectrum B-lactamases
Resistant to most if not all B-lactams
What is CPE?
Carbapenemase Producing Enterobacteriacaie
Immune to carbapenems and unfortunately often a lot of other antibiotics too.
Endemic in some countries healthcare
VRE?
Vancomycin REsistant Enterococci
enterococcus Faecium/Faecalis
What is MRSAs method of resistance?
Altered PBP binding sites, hence why its still weak to glycopeptides
What gram +ve organism is partiall resistant to flucloxacillin?
Staph. Aureus
Some strainds are resistant
Why wouldnt you use amoxicillin fo blind gram-ve coliform treatment?
20-30% of striands are now ressistant to it
How would we most accurately determine antibiotic sensitivty?
The MIC & MBC
Do all antivirals inhibit nucleic acid synthesis?
NO,
What are the 4 bi Cs broad spectru antibiotics known for leading to a rise in CDI?
Cephalosporin
Clindamycin
Co-Amoxiclav
Ciprofloxacin
Which cephalosporin generations are best for Gram -ve organisms?
The most recent, i.e. 3rd gen
Which cephalosporins are best for gram +ve organisms?
The oldest, i.e. 1st gen
Which generation of cephalosporin is effective against pseudomonas?
Third gen specifcally ceftazidime
