Adverse Drug Reactions and Interactions Flashcards
What are the three key determinants of toxicity?
Drug interactions
Altered microbial flora
Hypersensitivity
What is the type A: augmented response?
The normal pharmacological response is undesirable
Dose related
Predicable
Usually managed by dose adjustment
What does c.diff produce as toxins and what is it’s effect?
Enterotoxin -destroy GI tractand a cytotoxic
Effect range from diarrhoea and life-threatening pseudomembranous colitis
What is type B : bizarre or idiosyncratic reaction
Unrelated to pharmacology, immune based or genetic
Unpredictable
Rare
Often severe
Give an example of drug hypersensitivity reaction to IgE and cell-mediated
Anaphylactic shock
Urticaria , laryngeal oedema, asthma
Contact dermatitis
Give two other examples of type B reaction
Penicillin allergy
Beta-lactam allergy
What should you do if someone reports a beta-lactam allergy
Includes penicillin, cephalosporins, carbapenems and monobactams
Clarify what this means and document
GI is common, Rx should continue
Rash= no more penicillins
Angioedema/anaphylaxis= no more beta-lactams
Give some examples of adverse skin reactions and what anti o tic causes them
Urticaria. Histamine
Erythematous eruptions.
Toxic epidermal necrolysis (sulphonamides and beta-lactams)
Stevens-Johnson syndrome (vancomycin, penicillins and sulphonamides
Many drugs metabolised by CYPs and either inhibition or induction can happen.
Is CYP2D6 inducible?
NO
What is different about induction metabolism and inhibition
Slow/rapid onset
Can’t reverse, but other can quickly
Therapeutic range helps monitor serum levels but how?
[toxi] - [therapeutic]
Pros and cons of aminoglycosides and ADR
Against gram-ve
Rapidly bactericidal and synergistic activity with penicillin
Cons. Poor lipid solubility (Low CNS penetration) activity pH dependent
No oral formulation
ADRs. Ototoxic and beohrotoxic
Glycopeptics
Gram positive activity -MRSA
No to oral or systemic infections
ADRs- ototoxic/nephrotoxic
Red-man syndrome, histamine-release during rapid infusions, give as slow IV infusion over at least 2 hours
Lincosamides
Broad spectrum resistance uncommon
Excellent CSF penetration
Bone marrow toxicity
