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IBDP Chemistry: Medicinal Chemistry

Medicinal Chemistry

October 23, 2022

In this chapter of IBDP Chemistry, we will learn about definitions in Medicinal Chemistry.

TD50

The dosage of a drug which is TOXIC in 50% of the population 

LD50

The dosage of a drug which is LETHAL in 50% of the population 

Therapeutic Window

The range of drug plasma concentrations for which it is effective without causing toxic effects 

Bioavailability

Refer to IBDP Chemistry, the fraction of the administered dose which reacts the drug target in the body

Tolerance

When the body becomes less responsive to the effects of the drug, LARGER AND LARGER DOSES are needed for the same effect 

Addiction

Where a user develops a physical dependence on a drug 

Side Effects

The negative effects of the administration of a drugs

Drug Receptor Interactions

When it comes to IBDP Chemistry,  many drugs are designed to target SURFACE RECEPTOR PROTEINS, these drugs can have different effects e.g.

  • Agonistic: Drug acts in a similar way to substrate, activating the receptor and the associated response 
  • Antagonistic: Drug blocks the substrate binding site and prevents the natural substrate from activating the receptor 
  • Allosteric: Drug binds to a site other than the substrate binding site. This may increase/decrease the receptors response to the natural substrate

Mild Analgesic

A drug which works by intercepting the pain stimulus at the SOURCE, it does this by preventing the synthesis of substances that cause pain. 

Strong Analgesic

A drug that work by temporarily bonding to opioid receptors in the BRAIN and present transmission of pain impulses

Compliance

Patient's willingness and ability to take a medication in the correct doses, at the correct times for the whole course prescribed 

Opiates

Naturally occuring narcotic compounds from opium poppy (Morphine)

Oploids

Any compound with a similar structure to morphine (Codeine, Heroin) 

Solubility

Opiates and Opioids must cross the Brain Blood Barrier to work, the more hydrophobic (non-polar) a compound is, the more rapidly it penetrates the BBB.  

High-level Waste

In IBDP Chemistry, waste which gives off large amounts of ionising radiation for long periods of time, these isotopes will have long half-lives and many nuclei decay each second

Low-level Waste

Waste which gives off small amounts of ionising radiation for short periods of time, these isotopes will have short half-lives and few nuclei decay each second

Chrial Auxiliary

An optically active substance that is temporarily encorparated into an organic synthesis so that is can be carried out asymmetrically with the formation of a single enantiomer

This is the end of this topic.