Option D: Medicinal Chemistry Flashcards
What are the five methods of drug administration?
- Orally (through mouth)
- Parenterally (through injection)
- Inhalation
- Rectally
- Transdermally (through application to skin)
What are the three parenteral methods of drug admministration?
- Subcutaneous (under skin)
- Intramuscular (into muscle)
- Intravenous (into vein)
What is the effective dose (ED50)?
The minimum amount of bioactive compound required to cause a therapeutic effect in half the population
What is the toxic dose (TD50)?
The minimum amount of bioactive compound required to cause an unacceptable adverse effect in half the population
What is the lethal dose (LD50)?
The minimum amount of bioactive compound required to kill half the animal population
How is the therapeutic index (TI) measured?
TI = TD50 / ED50
What is the therapeutic window?
The range of values between ED50 and TD50
What is bioavailability?
The fraction of administered dosage that enters the bloodstream (or reaches target organ)
Why do drugs taken orally have a lower bioavailability than drugs administered intravenously?
- Not all drug absorbed
- Some destroyed by enzymes/stomach acid
- some metabolised due to first-pass effect (first destination is liver where bioactive compound may be metabolised and cleared)
What is the importance of polar and non-polar groups in drugs?
- Polar groups are soluble in water
- Non-polar groups can pass through hydrophobic cell membranes and blood-brain barrier
What are side effects?
Non-beneficial/unintentional effects a drug has on the body
What is tolerence?
When a person needs an ever increasing amount of a drug to gain the desired effect
What is addiction?
A compulsion to keep taking a drug
How do drugs interact with the body?
Bioactive compound must interact with and fit the biding site of an enzyme or cellular receptor
What are the two ways companies identify a lead compound?
- Screening of a large library of compounds
- Seeking to improve an existing compound
What are five factors to consider when choosing a compound for clinical trials
- yield of required drug
- cost to synthesize drug
- side effects
- solubility of drug
- chemical stability of compound
What is the placebo effect and how can it be prevented?
Patients report an improvement in condition without taking the drug. This can be prevented by using a placebo (medicine without the active ingredient) and a double-blind trials where neither patients nor doctros know if the patient has a placebo
Which plant is salicylic acid obtained from?
Willow bark