General Principles of Pharmacology Flashcards
List the four main protein targets for drugs.
Enzymes
Carrier/Transporters
Ion Channels
Receptors.
What is a receptor?
A protein in the body that acts as a recognition site for natural chemical signals (e.g., neurotransmitters, hormones).
What is an agonist?
A drug that mimics the body’s natural chemical signal, producing the same or an enhanced effect.
What is an antagonist?
A drug that blocks the body’s natural chemical signal, preventing its effect.
Define drug affinity.
The likelihood of a drug binding to a receptor.
Define drug efficacy.
The likelihood of a bound drug to elicit a response.
What is drug potency?
The combination of a drug’s affinity and efficacy.
What is a full agonist?
A drug that elicits the maximal tissue response.
What is a partial agonist?
A drug with similar affinity as a full agonist but with less efficacy, thus producing a smaller response.
Describe competitive antagonism.
An antagonist competes with an agonist for the same receptor binding; it is surmountable (able to overcome) with higher agonist concentrations.
What is irreversible antagonism?
An antagonist binds permanently to a receptor, making the effect non-surmountable.
Non-surmountable = the effect of the drug blocking the receptor cannot be overcome, no matter how much of the activating drug (agonist) you add.
Define non-competitive antagonism.
An antagonist blocks the downstream effects of an agonist, not affecting the binding of the agonist itself. (blocks the effect of an agonist rather than the binding of it)
What is chemical antagonism?
An antagonist combines with a drug in solution, inactivating the drug (e.g., protamine-neutralizing heparin).
What is pharmacokinetic antagonism?
An antagonist reduces another drug’s concentration by altering its metabolism or excretion.
Define physiological antagonism.
An antagonist with an opposing biological action to the agonist, cancelling its effect (e.g., histamine vs. omeprazole).
