BNS - Psychopharmacology

Question 1

Define drug

Answer 1

An exogenous chemical not necessary for normal cellular functioning that significantly alters the functions of certain cells of the body when taken in relatively low doses

Question 2

Define site of action

Answer 2

Points at which molecules of drugs interact with molecules located on or in cells of the body, thus affecting some biochemical processes of these cells

Question 3

Routes of drug administration (9)

Answer 3

• Intravenous injection
• Intraperitoneal injection
• Intramuscular injection
• Subcutaneous injection
• Oral administration
• Inhalation
• Topical administration
• Intracerebral administration
• Intracerebroventricular administration

Question 4

Lipid solubility

Answer 4

• Determines rate at which drug reaches sites of action in the brain
• Blood brain barrier works only for water soluble molecules, so molecules that are soluble in lipids pass through cells lining the capillaries in CNS, and rapidly distribute throughout the brain

Question 5

How to measure effectiveness of a drug

Answer 5

Plot a dose-response curve

Question 6

Drug response curve

Answer 6

• Subjects get various doses of a drug (mg/kg of body weight)
• Heavier subject – more widely distributed drug
• Increased doses until a point of maximum effect is reached; then increasing dose of the drug does not produce any more effect

Question 7

Therapeutic index

Answer 7

Ratio for two numbers between Dose that produces desired effect in 50% of sample; and Dose that produces toxic effect in 50% of sample

(Lower the therapeutic index, the more care must be taken in prescribing the drug)

Question 8

Affinity of a drug

Answer 8

Readiness with which the two molecules join together

Two drugs with identical sites of action can vary in effectiveness if they have different affinities for binding sites

Question 9

Drug tolerance

Answer 9

• A decrease in the effectiveness of a drug that is administered repeatedly
• Result of body’s attempt to compensate for the effect of drug

Question 10

Drug sensitization

Answer 10

An increase in the effectiveness of a drug that is administered repeatedly.

Question 11

Withdrawal symptoms

Answer 11

The appearance of symptoms opposite to those produced by a drug, when the drug is administered repeatedly and then suddenly no longer taken.

Eg: heroin

Question 12

Placebo

Answer 12

An inert substance that is given to an organism instead of a physiologically active drug; used experimentally to control for the effects of mere administration of a drug.

Has no SPECIFIC physiological effect

Question 13

Antagonist

Answer 13

A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell

Question 14

Agonist

Answer 14

A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell

Question 15

Types of drug tolerance

Answer 15

Metabolic
Cellular
Learned

Question 16

Define neurotransmitters

Answer 16

Have modulating effects rather than information-transmitting effects; tends to activate or inhibit entire circuits of neurons that are involved in particular brain functions

Question 17

Ach is found in which parts of the brain & functions

Answer 17

Dorsolateral pons (REM sleep)
Medial septum (memory - hippocampus)
Basal forebrain (learning)

Question 18

Drugs that affect ACh release

Answer 18

Botulinum toxin (botox) - antagonist 
Black widow spider's venom - agonist

Question 19

Drugs that affect ACh receptors

Answer 19

Nicotine - affect on ionotropic receptor (mostly in PNS)

Muscarine - affect on metabotropic receptor (mostly in CNS)

Question 20

Drugs that block Ach receptors

Answer 20

Atropine - blocks muscarinic receptors (used in surgery)

Curare - blocks nicotinic receptors (causes paralysis)

Question 21

Three major dopaminergic pathways

Answer 21

Nigrostriatal system (in substantia nigra)
Mesolimbic system (in ventral tegmental area)
Mesocortical system (in ventral tegmental area)

Question 22

Functions of dopamine

Answer 22

Movement, attention, learning, and the reinforcing effects of drugs that people tend to abuse

Question 23

Drugs affecting dopamine

Answer 23

L-dopa, amphetamine, reserpine, methamphetamine, cocaine, and methylphenidate (Ritalin), Chlorpromazine

Question 24

Location of serotonin

Answer 24

Raphe nuclei of the midbrain, pons, and medulla

Dorsal and medial raphe nuclei project axons to the cerebral cortex

Question 25

Function of serotonin

Answer 25

• Regulation of mood; in the control of eating, sleep, and arousal; and in the regulation of pain.
• Also in control of dreaming

Question 26

Drugs involved with serotonin

Answer 26

Fluoxetine (Prozac)
Fenfluramine
LSD
MDMA