Receptors Flashcards
What is the purpose of the Food and Drug administration (FDA)?
To approve or reject applications from drug companies to market new drugs; old drugs which fail to meet, purity, safety or efficacy standards may be removed from the market
Purpose of the Drug enforcement Administration (DEA)
To establish a balance between legitimate medical needs while minimizing the availability of the drug for abuse
Purpose of the 1970- Comprehensive Drug abuse, Prevention and Control Act (Controlled substances Act)
Regulates the manufacture, distribution, dispensing, use and possession of all CNS drugs with abuse potential with the exceptions of alcohol and tobacco
What schedule of drug has the highest abuse potential?
C-1 (illegal drugs)
What schedule of drug has the least abuse potential?
C-V (gabaproteins)
What is an example of C-I drugs?
Illegal drugs like heroin, LSD, marjuana, mescaline, phencyclidine (PCP)
What is an example of C-II schedule drugs?
Morphine, methylphenidate
What is an example of C-III schedule drugs?
Tylenol #3 (codeine mixtures)
What’s an example C-IV schedule drugs?
Benzodiazepines (for people with insomnia)
What are some examples of C-V schedule drugs?
Gabapentin, some codeine-containing cough syrups
What are some things that can be receptors?
Enzymes, proteins, nucleic acids
What are most receptors? Why?
Proteins
- undergo 3D structural changes
- have spatially and energetically favorable molecular domains for binding
What do true receptors elicit?
A biological response when bound by an agonist
How must the interaction (binding) between drug and receptor be?
Selective binding of drug to biological target before a response can take place
A drug will elicit a biological response when?
When bound to an agonist
What are inert binding sites?
Places where a drug can bind, but there will be no biological response elicited
Example of plasma proteins; what kind of binding sites do these have?
Albumin; Inert binding sites (drug can bind to albumin but it won’t elicit a biological response)
What can ionization of a drug effect?
Ionization can effect the amount of drug that’s able to bind to an actual receptor
Physical characteristics of drugs
- solid (aspirin)
- liquid (ethanol)
- gas (nitric Oxide)
Nature of drug size
- small (lithium) to large (T-PA)
- b/w 100 and 1000 MW
- related specifically for a receptor and movement within the body
Strength of drug reactivity and bonding in order of strongest to weakest
1) covalent
2) ionic
3) hydrogen
4) dipole induced dipole
5) hydrophobic
Selectivity of drug reactivity and bonding in order of strongest to weakest
1) hydrophobic
2) dipole induced dipole
3) hydrogen
4) ionic
5) covalent
Drug reactivity and bonding of covalent bonds
- Strong bond (tight bond to receptors, making it last longer in the body)
- Irreversible (not very selective; can form with many things)
Drug reactivity and bonding of hydrophobic bonds
- Weak bonds (only last a couple of house)
- Important for lipid interactions (very specific)
What are two details for drug shape?
1) crucial for proper binding (lock and key)
2) chirality (stereoisomerism)
What’s the term for superimposed?
Achiral
What’s the term for something that can’t be superimposed?
Chiral
What is the active form of a drug?
The proper enantiomer; it fits into the receptor to elicit a response
Explain a racemic mixture of a drug
2 equal amounts of s-isomers and r-isomers; only one of them is the active form, so the other half is the part that is responsible for the side-effects of that drug
Examples of ligand gated ion channels
- nicotinic acetylcholine receptors
- glutamate receptors
- GABA receptors
How many subunits are on nicotinic acetylcholine receptors, and what are they?
5 subunits (beta, delta, gamma, and 2 alpha subunits)
How many molecules of acetylcholine have to bind to open the channels?
2 units (1 per alpha subunit)