Pharmacokinetics & Pharmacodynamics

Question 1

T max

Answer 1

Time to max concentration

Question 2

C max

Answer 2

Max concentration

Question 3

Oral

Answer 3

Safe, non-invasive, but very variable. Impact is slow, dose isn’t precise as drug is metabolised. Drug is absorbed from gastro-intestinal tract.

Question 4

Rectal

Answer 4

Absorbed via rectal mucosa. Alternative intestinal route. Same benefits and costs but is more invasive.

Question 5

Intravenous

Answer 5

Injected into the bloodstream, very rapid onset, very precise dosing, can be hazardous and there is no way to reverse it.

Question 6

Inhalation

Answer 6

Fast onset, intense effects, no loss of drug through first pass metabolism. Can cause lung damage and there’s no way for remove it.

Question 7

Drugs and the bloodstream

Answer 7

Circulated in the blood plasma, to impact the brain they must penetrate the CNS. The brain received 20% of the blood. Impacted by lipid solubility and BBB.

Question 8

Blood brain barrier

Answer 8

Tight packed capillaries, smaller than anywhere else. Covered by glial sheaths and has a special transporter system.

Question 9

Drug metabolites

Answer 9

When drugs are metabolised they become more or less active. Metabolite produced can be psychoactive drugs. Can also lead to cross tolerances due to shared enzymes.

Question 10

Drug half lives

Answer 10

T 1/2. Can be distribution half life, elimination half life or plasma half life.
Distribution is time until half is distributed. Elimination until half is eliminated and plasma is for half to circulate in plasma.
Key to creating dosage times.

Question 11

Pharmacokinetic graphs

Answer 11

Show dose response curves, measuring ED50, Side effects and LD50.