Drug Reactions, Adverse Reactions and Allergies Flashcards
How are drugs pharmacologically developed?
1) Serendipity: By random chance e.g. Penicillin
2) Rational Drug Design e.g. propanolol
What is drug development?
Process of bringing new pharmaceuticals to market
What is drug re-purposing?
Technique where existing drugs are used to treat emerging and challenging diseases
How does rational drug design come about?
Process of developing an antagonist from an agonist by looking at solubility, electrostatic charge and bulk
What 3 things do the chemical properties of a drug influence?
1) Elimination
2) Distribution
3) Administration
What 4 receptors do drugs target?
1) Kinases
2) Ligand Ion Channels
3) GPCR
4) Cytosolic/Nuclear
What is gene therapy?
Experimental technique using genes to either treat or prevent disease
What are 3 examples of gene therapy?
1) Replace a mutated gene with a healthy copy
2) Inactivate a gene that isn’t correctly functioning
3) Introduce a new gene into the body to help fight a disease
What are the pharmacokinetic issues of immunotherapy? (3)
1) Immunoglobulin: Not filtered by the kidneys
2) FcRn receptor: Absorb IgG into cells to protect them from metabolism
3) Mouse AB’s: Not substrates for human FcRn (have half the half-life)
What are the 3 types of Antibody?
1) Polyclonal: Non-specific foreign protein e.g. antilymphocyte globulin
2) Monoclonal: Single specificity
3) Humanised: Non-self issues
Define an adverse drug reaction?
Noxious and Unintended response to a drug
What are the 6 types of Rawlins-Thompson adverse reactions?
1) Type A (Augmented Pharmacological)
2) Type B (Bizarre/Idiosyncratic)
3) Type C (Chronic)
4) Type D (Delayed)
5) Type E (End of Treatment)
6) Type F (Failure of Therapy)
What are the events and treatment of a Type A reaction?
Augmented, very common, dose related and predictable physiological effects from drug
TREATMENT: Reduce the dose
What are the events and treatment of a Type B reaction?
Bizarre, unpredictable, immunological mechanisms and hypersensitivity, (History of allergy)
TREATMENT: Immediately withdraw the drug
What are the events of a Type C reaction?
Chronic, occurs after long term therapy
What are the events of a type D reaction?
Delayed, occurs many years after treatment
What are the events of a type E reaction?
End of use, withdrawal of drug after long use (complications of stopping med.)
What is idiosyncrasy?
An inherent abnormal response to a drug
What are some common ADRs?
Constipation, Diarrhoea, Nausea, Hypotension
What are yellow cards?
Voluntary reporting system for ADRs
What does a black triangle represent?
A medicine undergoing additional monitoring (All routine medicines only reported for SERIOUS reactions)
What happens in each of the 4 hypersensitivity reactions?
1: IgE becomes attached to mast cells and cross-links -> Mast cell degranulation -> Histamine release
2: IgG mediated cytotoxicity
3: Immune complex deposition: Not cleared by innate immune system –> Inflammatory response
4: T cell mediated
What are the main features of anaphylaxis?
1) Rapid onset
2) Blotchy rash
3) Swelling of lips and face
4) Wheezing
5) Hypotension
6) Cardiac Arrest
What is non-immune anaphylaxis?
AP from direct mast-cell degranulation from non previous exposure e.g. drug reaction
