Week 1 pharmacodynamics Flashcards
Describe the idea of affinity
The strength of the drug and receptor
Buprenorphine= high affinity, more likely to displace other drugs in the opioid receptor
Describe the specificity of drugs
Binds to limited group of receptors, cell types, or organs
Less specific= more side effects ( albuterol acts on cardiac cells and lungs)
Describe the intrensic activity of drugs
Efficacy
Ability to produce a cellular response upon binding (Morphine is more effective than buprenorphine to produce euphoria)
Maximal vs partial agonism
Maximal effect- maximal response has been reached (or all receptors are occupied)
Partial- drug produces a biological response to limited extent no matter how high the concentration or dose; lower Emax than full agonist
Describe competative agonism
Reversible, overcomeable
- Get naloxone for opoid receptors, but more opoids can overcome the effects of naloxone
Describe noncompetitive antagonist
Irreversable, insurmountable.
Ketamine at NMDA- glutamate receptors
Describe allosteric receptor interactions
Separate site where drugs bind, changes efficacy or binding affinity of agonist receptor site. Benzos bind to allosteric GABA site, enhance receptor affinity. Allow natural gaba activity to be even more pronounced
Is a drug with a lower or higher EC50 more potent
A drug with a lower EC50 is more potent- more efficacy at lower concentration
i.e. fentanyl»morphine at same concentration, fentanyl has higher impact.
What is tachyphylaxis
complete tolerance
Increased metabolism or drug efflux transporters leads to what
resistance
What type of reaction is between ibuprofen and rivaroxaban (an anticoagulant)
Pharmacodynamic ( ibuprofen thins blood and rivaroxaban thins blood).
What is an anticoagulant that inhibits vitamin K expoxide reductase, preventing carboxylation activity?
Warfarin (Comodulain) is an anticoagulant that inhibits VKORC
In the case of a warfarin overdose, what do you give a patient to reverse it?
Vitamin K and 4-factor Prothrombin complex concentrate (PCC)
What are the 2 goals of hemophilia treatment
- maintain adequate factor levels
- improve morbidity (i.e. joint pain related to hemarthritis is a bleed risk)
Prophylaxis hemophilia factor activity goal
Prevent spontaneous bleeding (particularly in joints)
maintain activity (30-50%)
Treatment of bleeding and trauma factor activity goal for hemophilia
100% activity, then 50-80% for 1 week
What is the biggest consideration for factor replacement
Antibodies can form against exogenous factors, like factor 8, leads to resistance to factor 8
What is given to paitents for hemophilia A patients with or without factor 8 inhibitors
Hemlibra (Hemophilia- liberated- with or without factor 8)
First line treatment for ITP
Corticosteroids (IVIG also)
What is heparin’s relationship to DITP
Injectible anticoagulent- probable causal relation to thrombocytopenia.
What do you need to moniter after starting heparin, and what is commonly caused?
Heparin-induced thrombocytopenia (HIT) can be caused, platelets can clump, so moniter PLTs after starting heparin, and if platelet count falls, stop heparin and related products immediately
