Flashcards in Pharm Deck (24):
What are the risk factors for adverse drug reactions?
What are the pharmacodynamic issues that may cause adverse drug responses?
– Target selectivity
– Target distribution
What are the pharmacokinetic issues that may cause adverse drug responses?
– Impairment of the organs of excretion (hepatic or renal dysfunction)
– Extremes of age
– Polypharmacy • Drug-interactions
What does LD50/ED50
The amount that it takes to help 50% and the amount of drug that it takes to kill 50% (of mice)
What are the two drugs that we need to remeber with a low therapeutic index?
• Cardiac glycosides
What are the dose dependant adverse drug reactions?
What are the not dose-dependant adverse drug reactions?
Why is adrenaline used in anaesthetic solutions?
It vasconstricts allowing fro a localised response
What is terfenadine?
It is a H1 receptor antagonist
It is a prodrug - it is converted to fexofenadine
What is a contradindication for Terfenadine?
Grapefruit juice (or CYP3A4 antagonists)
What are the adverse affects or Terfenadine?
It is a H1 receptor antagonist but it also inhibits K+ channels and can cause arrhythmias
What happens in paracetamol toxicity?
Cytochromes break it down using glutathione which can then be excreted
If the glutathione pathway is fully occupied then the reactive intermediates interact with cellular proteins and cause liver damage
What is suxamethonium?
How is codeine converted to morphine
What causes issues when taking suxamethonium?
Absence of pseudocholinesterase means that is cannot be broken down and continues to exert its effect
What is a hypersensitivity reaction to drugs?
single exposure triggers extreme response harmless skin reaction to life threatening anaphylaxis, hemolysis or bone marrow depression
Type 1 hypersensativity reactions?
- immediate, inflammation - anaphylaxis
- allergen specific IgE, mast cells
- penicillins, lignocaine, atropine, aspirin
Type 2 hypersensativity reactions?
- cytotoxic, anaemia, thrombocytopaenia
- cell surface antigens IgG/IgM
- sulphonamides, penicillins. halothane - liver damage
Type 3 hypersensativity reactions?
- serum sickness (antivenoms, antisera)
- circulating immune complex
Type 4 hypersensativity reactions?
- Delayed, contact dermatitis (poison ivy)
- T-lymphocytes lymphokines
- Penicillins -> mercury, latex
Side effects of atropine?
• anti-Salivation Lacrimation Urination Defecation • context specific
Effects of Atropine overdose?
• blurred vision, difficulty swallowing, sedation, death
Ideosyncratic effects of atropine?