Medicinal Chemistry Flashcards
What are the different ways to administer a drug?
Orally, through eye/ear drops, suppository, parenteral (injection), skin patches, and inhalation
Define bioavailability
The fraction of an administered drug that reaches the blood supply.
What factors affect the bioavailability of drugs?
How they are administered, their solubility, and their functional groups
What phenomenon accounts for the low bioavailability of orally administered drugs?
The first-pass effect; this means that after drugs are swallowed, enzymes in the digestive tract alter them chemically and then they are further broken down in the liver.
What are the three types of side-effects?
Beneficial, benign, and adverse
What is the difference between tolerance and addiction?
Tolerance is when the physiological effect of a drug is diminished because of repeated doses (which means more is needed to have the desired effect). Addiction occurs when an individual becomes dependent on a drug to feel normal and withdrawal symptoms occur when the drug is withheld.
What is therapeutic window?
The concentration of a drug that must be present in the blood supply for it to have the therapeutic effect but not produce adverse effects.
How is the therapeutic index calculated?
the ratio of the minimum dosage required to produce the therapeutic effect to the maximum dosage that causes adverse effects in 50% of the population (for this second measurement, toxicity is used for humans and the lethal amount is used in animal studies)
The effectiveness of a drug depends on on its ability to bind to receptor sites in the body. What type of bonding usually occurs between the drug and the receptor sites?
Non-covalent forms of bonding such as ionic and hydrogen bonds, van der Waal’s forces, or hydrophobic interactions.
What is another name for pain killers?
Analgesics
What is the name for the chemicals that activate pain receptors around the body?
Prostaglandins
How are prostaglandins produced?
They are released by cells damaged by chemical, thermal, or mechanical energy
Other than signaling pain receptors, what effect do prostaglandins have?
They cause the inflammatory response (by widening blood cells near the site of injury) and they raise the body’s temperature (fever)
There is a type of pain killer that prevent the stimulation of local pain receptors and inhibit the function of prostaglandins. There are two names for this type of pain killer. What are they?
Mild analgesics or Non-narcotics
The bark of the (1)________ tree contains (2)_______, which allows it to alleviate pain; however, it (3)_______
(1) willow
(2) salicylic acid
(3) tastes like crap
The Bayer company made a (1)______ of salicylic acid, which makes it taste better. It is called (2)_____, and it reduces pain as well as fever, making it both an analgesic and an (3)_________.
(1) ester-derivative
(2) aspirin
(3) antipyretic
What is salicylic acid reacted with to produce aspirin, what is this reaction called, and what is a byproduct of the reaction?
ethanoic anhydride
esterification
ethanoic acid
How is the ethanoic acid byproduct removed from the aspirin?
The product is cooled, which causes crystals to form then washed with water. The ethanoic acid dissolves in the water and gets washed away, but the aspirin isn’t soluble in water to it remains separate.
How is the aspirin purified after having been washed?
In a process called recrystallization, the crystals are dissolved in hot ethanol and then slowly cooled. This separates the aspirin because it is less soluble than the impurities and unreacted salicylic acid. Then filtration is used to remove the salicylic acid crystals.
How can the identity of aspirin be confirmed?
melting point determination (it has a higher and better-defined melting point than the mixture of salicylic acid and alcohol) and infrared spectroscopy
What are the main differences in the IR spectra of salicylic acid and aspirin?
salicylic acid has a peak for its hydroxyl group and acetylsalicylic acid has a peak for its ester group
What is another side effect of aspirin?
it works as an anticoagulent, which is good for people at risk of heart attacks and strokes.
What are adverse side effects of aspirin?
they cause ulcers and people can be allergic to them
How can aspirins bioavailability be increased?
It can be reacted with NaOH to make it more polar and therefore more soluble in the blood (which is polar)