Module Eight: Behavioural Pharmacology, Psychopharmacology & Neuropharmacology Flashcards
What is behavioural pharmacology?
Assesses the effects of unknown drugs on behaviours with known neural substrates and psychopharmacological properties
Primarily for novel drug development
Determine potential therapeutic effects of novel drugs
What is psychopharmacology?
Uses drugs with known properties to determine the neural substrates of behaviour and understand the mechanisms for CNS disturbances
What is neuropharmacology?
Attempts to understand the molecular basis of the neural actions of the drugs
Why have animal models in psychiatric illness?
Objective: to determine possible neural causes of illness; to screen for new drugs that may improve the pharmacotherapy of the illness; to increase our understanding of the neural substrates of behaviour
What are the three types of validity in Animal models.
- Predictive validity
- Face validity
- Construct validity
What determines predictive ability?
True negatives, false negatives: known treatments are predicted to be ineffective
True positives and False positives: known ineffective drugs are predicted to be affective
What does sensitivity refer to?
How easily an animal model detects true positives
P HIT/ (p HIT + MISS)
What does specificity refer to?
How well a test avoids making false positives
1- p false alarm
What is face validity?
Model that has validity based on analogy rather than homology
What is construct validity?
The model has sound theoretical rationale
Define: phenomenology
The study of structures of consciousness as experienced from the first person point of view
What was the first antipsychotic
Chlorpromazine
Tolerance
The effect of drug declining with repeated treatment due to a shift to the right in the DCR
Sensitisation
Effects of a constant dose may increase with repeated treatment- left shift of DCR
Pharmacokinetic factors altering drug repsponse
Induction of metabolising enzymes
Age related changes in mets losing enzymes
Circadian rhythms
Progressive hepatotoxicty/ renal toxicity
Saturation of non specific or lipid / protein binding compartments
Pharmacodynamic factors: post synaptic
Receptor density changes
Receptor affinity changes
Efficacy changes
Pharmacodynamic factors: presynaptic
Changes in release rates of endogenous neurotransmitter
What is pharmacodynamic increase of response called?
Fast and short term: Reverse tachyphylaxis
Slow and long lasting: sensitisation, supersensitivity, up regulation
Pharmacodynamic decrease in response is called:
Fast and short term: Desensitisation, auto inhibition, tachyphylaxis
Slow and long lasting: tolerance, down regulation, subsensitivity
Receptor density changes
Reduction in density with agonists
Increase in density with antagonists
Subsensitivity
Resultant from a chronic agonist use resulting in a reduction in receptor density
Supersensitivity
Antagonist chronic use causing increase in receptor density
The affinity effects are due to
Phosphorylation of sites on the receptor or conformational shifts of the receptor due to occupancy by drug or neurotransmitter
