Option D - Medicinal Chemistry Flashcards
What was aspirin extracted from?
- willow bark
What was morphine extracted from?
- poppy seeds
What is a drug or medicine?
- any chemical (natural or human-made) that does one or more of the following:
alters incoming sensory sensations, alters mod or emotions, alters the physiological state
What are drugs or medicine usually taken for and how do they accomplish it?
- to improve health
- accomplish this by assisting the body in its natural healing process
What is the “placebo” effect?
- when the body can be “fooled” into healing itself
What must usually happen for a drug to reach the site where their effect is needed?
- absorbed into the bloodstream
What are the four main methods of administering a drug?
- oral, by mouth
- inhalation
- rectal, through the anus
- parenteral, injection
Why are drugs sometimes applied topically?
- so that the effect is limited mainly to the site of the disorder such as the surface of the skin
- may come in the forms of creams, ointments, sprays and drops
What is the therapeutic window?
- the range of dosages between the minimum amounts of the drug that produce the desired effect and a medically unacceptable adverse effect
How does drug tolerance occur?
- the body adapts to the action of the drug
What is the danger of drug tolerance?
- as the dose increases so do the risks of dependence and the possibility of reaching the lethal dose
What is addiction (/substance dependence)?
- reducing or stopping the drug causes withdrawal symptoms
What is bioavailability?
- the fraction of the administered dosage that reaches the target part of the human body
What are examples that affect bioavailability?
- polarity of the drug
- types of functional groups present in the drug
- method of administration
What is an analgesic?
- pain killer
What is an antipyretic?
- fever depressent
What is the ethanoate ester of salicylic acid?
- Aspirin
How is Aspirin thought to work?
- preventing a particular enzyme, prostaglandin synthase, being formed at the site of the injury or pain
What else can Aspirin be used for except for pain?
- prevents blood clotting
What is the most common side effect of Aspirin and how is this effect increased?
- causes bleeding in the lining of the stomach
- this effect is increased by taking aspirin with alcohol as alcohol has a synergistic effect
Why can Aspirin be fatal when exceeding the safe dose?
- the salicylic acid leads to acidosis due to a lowering of the pH of the blood
Why is Paracetamol often preferred to Aspirin?
- its side-effects are less problematic
How is a good yield of Aspirin obtained?
- salicylic acid is reacted with ethanoic anhydride in the presence of an acid catalyst
How can Aspirin’s solubility be increased?
- by reacting it with sodium hydroxide to turn it into an ionic salt
Why is Aspirin slightly polar?
- due to the carboxylic acid group it is not very soluble in water
Where does original penicillin occur?
- in mould
Where does original penicillin occur?
- in a mould
How does Penicillin work?
- by preventing bacteria from making normal cell walls
How do strong analgesics work?
- work by interacting temporarily with receptor sites in the brain without depressing the central nervous system, with the results that pain signals within the brain and spinal cord are blocked
What are the most important naturally occurring strong analgesics and what are they known as?
- morphine and codeine found in the opium poppy
- known as opiates or narcotics
What is diamorphine (/heroin)?
- more powerful painkiller than morphine but also more addictive