Drug Dependence and Antidepressants Flashcards
How do cocaine and methamphetamine differ?
In their selectivity for receptors in the CNS and their affinity
What do the cortical areas/circuits involved in drug abuse and addiction control?
Motivation/drive
Memory/learning
Reward/salience
Inhibitory control
What is the biochemical effect of drugs of dependence?
Increase dopamine in the nucleus accumbens
What effect does amphetamine have in the CNS?
Releases DA, 5HT and NA
What is the mechanism of dependence in amphetamine use?
Dopaminergic actions in nucleus accumbens
What effect does MDMA have in the CNS?
Releases DA and 5HT
What physiological effect of MDMA is of most concern in terms of its potential to cause fatalities?
Disrupted thermoregulation (causing chills and sweating, can lead to dehydration and death)
What is the characteristic effect of LSD use?
Confusion of sensory modalities leading to visual, auditory and tactile hallucinations
For which drugs of dependence does tolerance occur?
LSD
Where does LSD act and what kind of activity does it have?
Agonist at 5HT-2 autoreceptors on neurones in raphe nuclei
To what drug class does caffeine belong?
Methylxanthine
List the 2 pharmacological actions of caffeine
Adenosine antagonist
PDE inhibitor
List 3 actions of ethanol on the CNS
Inhibits Ca2+ channel opening
Enhances GABA action via GABA-A receptors
Inhibits glutamate receptors (NMDA-type channel)
What is the effect of flumazenil?
Blocks the action of ethanol on GABA-A receptors
List 5 neurological signs of ethanol dependence
Tremor Agitation Hyperactive reflexes Convulsions Delirium
List 5 physical signs of ethanol dependence
Anorexia Vomiting Postural hypotension Sweating Hyperpyrexia (extremely high fever)
What class of receptors are cannabinoid receptors?
GPCRs
What is the name of the endogenous chemical that activates cannibinoid receptors?
Anandamide
List 4 peripheral effects of THC
Tachycardia
Vasodilation
Reduced intraocular pressure
Bronchodilation
List 2 1st generation classes of antidepressants
TCAs
MAOIs
List 2 2nd generation classes of antidepressants
SSRIs
SSNRIs
List 2 3rd generation classes of antidepressants
Novel monoaminergic drugs
Non-monoaminergic drugs
List 3 pharmacological actions of TCAs
Inhibit neuronal uptake of NA and 5HT
Antagonise a-adrenoceptors, muscarinic receptors, histamine receptors and 5HT receptors
Quinidine-like membrane stabilising action at very high concentrations
List 4 drawbacks of using TCAs
Poor selectivity
Clinical effect takes weeks to develop
Narrow therapeutic window
Long(ish) half life meaning gradual accumulation may occur, causing slowly developing side effects
What effect do MAOIs have on the CNS?
Increase levels of 5HT, NA and DA
List 2 irreversible MAOIs
Phenelzine
Tranylcypromine
What is the “cheese reaction”?
Interaction between irreversible MAOIs and tyramine (in many foods including cheese, red wine, chocolate, bananas) causing hypertensive crisis
Name a reversible MAOI. What MAO subtype is it selective for?
Moclobemide, selective MAO A
List 4 side effects of reversible MAOIs
Postural hypotension
Dizziness
Nausea
Insomnia
