Psychoactive Drugs

What are psychoactive drugs?

Drugs which alter how we feel or act by interacting with the nervous or endocrine system

How do psychoactive drugs affect the body?

• Inhibit or reinforce enzymes

• Block or activate receptors

• Interact with neurotransmitters and hormones

• Attack “invaders”

What is an agonist drug?

Mimics or enhances the effect of a neurotransmitter

What is an antagonist drug?

Blocks the effect of a neurotransmitter

What are auto receptors?

Receptors located on the presynaptic neuron that regulate neurotransmitter release. They help maintain balance in neurotransmission.

What is the quickest way to get drugs into bloodstream?

Intravenous route - injection

What is the slowest way to get drugs into bloodstream?

Oral administration - ingestion

What is the Blood-Brain barrier?

A selective barrier that protects the brain from harmful substances while allowing essential nutrients to pass through.

How do lipid soluble drugs interact with blood-brain barrier?

They easily cross the barrier due to their ability to dissolve in the lipid membranes of the cells.

How are drugs eliminated?

• Chemical breakdown

• Excretion (kidneys and urine)

How are lipid-soluble drugs eliminated?

Accumulate in fat cells which slows clearance from body

What is the biological half-life?

Time it takes for drug concentration in bloodstream to half its peak concentration