Pharmacology Flashcards
ß1 Receptor
- Sympathetic
- Heart
ß2 Receptor
- Sympathetic
- Bronchi in the lungs
α1 Receptor
- Sympathetic
- Smooth muscle, periphery
α2 Receptor
- Sympathetic
- autoreceptors
M1 Receptor
- Parasympathetic
- Brain
M2 Receptor
- Parasympathetic
- Heart and autoreceptors
M3 Receptor
- Parasympathetic
- Airways and exocrine glands
Nicotinic Receptor
- Parasympathetic
- brain and neuromuscular junction
Adverse effect of drugs may be :
- An extension of the desired effect: dose related
2. Unrelated to the desired effect: surprise toxicity
What are the criterias to be CEPA toxic?
CEPA toxic = persistence + bioaccumulation + toxic
What’s the approach of treatment of poisoning?
- Maintain vital functions: ABCD
- Identify poison
- Decontaminate – prevent further absorption
- Enhance elimination (like use of activated charcoal)
- Antidote: chelating agents, antivenins, receptor antagonists
Distinguish first order and zero order DRUG and KINETICS
DRUG:
First order drugs always follow first order kinetics (proportional to the concentration) while 0 order drug follows 0 order kinetics when saturated and then 1st order kinetic when below threshold of saturation. YOU CAN PREDICT THE CLEARANCE OF FIRST ORDER DRUGS
KINETICS:
1. First order kinetics (elimination): amount eliminated/unit time depends on the amount in the compartment and thus can be predicted.
2. In a 0 order kinetic, you can’t predict the T1/2.
(Half life T1/2 = time to decrease 50%)
What are factors of the drugs that influence its absorption?
o Lipid solubility (more hydrophobic, faster) o pH (depends on the tissue that absorbs it and f the drug is ionized or not) o Blood flow to tissue (more blood flow = faster but stay less longer) o Bioavailability (depends on the route)
What are the 2 phases of drug metabolism?
Phase 1: drug metabolite with modified activity (lipophilic)
Phase 2: Inactive drug metabolite (hydrophilic)
What are the different receptor superfamilies ?
Receptors: recognizes a transmitter or hormone, triggers cellular response
Types:
1. Nuclear receptors
2. Catalytic receptors (they recruit proteins to do stuff, like RTK)
3. Cytokine receptors
4. Ligand-gated ion channels
5. Receptors coupled to G proteins (most targeted receptors by drugs)
Define the types of agonist/antagonist.
Categories:
- Full agonist (high efficacy)
- Partial agonist (medium efficacy)
- Antagonist (0 efficacy)
- Inverse agonist (negative efficacy)
True or false: The higher is a therapeutic index, the safer the drug is.
True !
List some of the factors that contribute to inter-patient variability.
Age Gender Renal and hepatic function Concurrent drugs Concurrent diseases Adverse/allergic reactions Pharmacogenetic (phenotype, pharmacokinetics, pharmacodynamics)
Non-compliance is a big contributor to therapeutic failure. What are its causes ?
Denial Forgetfulness Stubbornness Embarrassment Side effects/interaction with other drugs
Explain pharmacokinetics and pharmacodynamics.
Pharmacokinetics: how it gets to the site, how it is distributed (ADME: absorption, distribution, metabolism, excretion)
Pharmacodynamics: pharmacologic effect, clinical response, how it acts (toxicity/effectiveness). WHAT DRUGS DO IN THE BODY
*Distinction: pharmacology includes ALL substances and effects on living cells (properties, effects, mechanism, pharmacokinetics, therapeutic use)
what’s a drug potency ?
is a measure of drug activity expressed in terms of the amount required to produce an effect of given intensity (based on EC50)
i.e. the dose that give 50% of the expected effect
What’s the therapeutic index ? what does it mean if high?
- TI (therapeutic index) = LD50 / ED50 = lethal dose for 50% of the person / dose that does an effect on 50% of the person
- the higher the TI, the safer the drug (increased margin of safety)
define compliance
sometimes called adherence, it’s the extent to which a patients follow treatment instruction
what are the 4 types of non-compliance ?
- patient fails to obtain the medication
- patient fails to take the medication as prescribed
- patient prematurely discontinues the medication
- patient (or another person) takes the medication innaproprietely
does a patient prefer to take more drugs less often in a day of less drugs more often ?
more drugs less often (the number of drugs doesn’t appear to be as important as the number of times a day doses must be remembered)
what’s a endogenous ligand ? What else can be ligand in the body ?
- a substance that the body makes (neurotransmitter, hormone or other mediator)
- drugs can also be ligands of the body’s receptor
what are the receptor that most drugs target ?
GPCR (récepteurs couplé aux protéines G)
do all drugs act on receptors ?
No.
what does a low dissociation constant (Kd) means ?
Kd = k2/k1. It reflects the affinity of a drug to a receptor.
the lower the Kd, the higher the affinity to a receptor
what are spare receptors ?
receptors where maximal effect occurs without all receptors occupied by agonist
what does constitutive receptor activity mean ?
that even without receptor activity, some receptors can be activated (do something)
in order for a inverse agonist to work, what does the receptors need to do when unbond ?
unbound receptors produce a detectable basal signal (constitutive receptor).
The response is then lower than the basal response when there’s a inverse agonist.