Psychopharmacology and Neuropharmacology Flashcards
What is psychopharmacology?
The study of drug-induced changes in mood, sensation, thinking, and behavior.
Describe the basic properties of psychiatric medications and where they act?
All psychiatric medications alter neuron function, are lipophilic, and cross the blood brain barrier. They act primarily through the synapse by altering neurotransmitter release or uptake, ion channel flow, second messenger systems, gene transcription, neurogenesis, and endocrine function.
What is the monoamine hypothesis? What do drugs that act on monoamines do? What do each of the monoamines do?
Based on the theory that depression is a result of depletion of monoamines, specifically serotonin, norepinephrine, and dopamine.
Drugs that act on this pathway enhance their availability mainly by preventing their degradation in the presynaptic neuron or by preventing their reuptake in the synapse. One drug specifically increases their synthesis.
Serotonin (raphae nuclei): modulates obessions, compulsions, anxiety, and mood
Norepinephrine (locus cereleus): modulates alertness, anxiety, and mood
Dopamine (ventral tegmental area and substantia nigra): modulates attention, pleasure reward, motivation, and mood
What psychiatric conditions are associated with monoamines?
Serotonin: mood disorders, anxiety disorders, OCD, eating disorders
Norepinephrine: mood disorders, anxiety disorders, ADHD, pain disorders
Dopamine: schizophrenia, ADHD, mood disorders, addictions
What excitatory amino acid is involved in psychiatric disorders? Where does it originate and what receptor does it bind? What conditions is it implicated in?
Glutamate: originates in cortico-cortical pathways, thalamo-cortical pathways, and extrapyramidal pathways (neocortex mostly) and binds NMDA receptors
Mediates mood, psychosis, seizures, learning and memory, and can cause cell death
Associated with schizophrenia, mood disorders, and Alzheimer’s
No official prescribed glutamatergic agent except for Alzheimer’s
What inhibitory amino acids are involved in psychiatric disorders? Where do they originate? What conditions are they implicated in?
GABA: exerts inhibitory effect by increasing chloride ion flow to hyperpolarize neurons. GABA neurons are ubiquitous throughout CNS.
- Related to anxiety disorders, insomnia, alcohol withdrawal, and pain disorders
- Benzodiazepines and barbiturates act on GABA regulated chloride channels
Glycine: acts via allosteric modulation of the NMDA receptor
What are acetylcholine and histamine implicated in?
Acetylcholine is implicated in Alzheimer’s disease which is treated with acetylcholinesterase inhibitors
Histamine is a biogenic amine involved in appetite, weight, and sleep.
What properties to antipsychotics share? What does dysregulation of this amino acid cause?
All antipsychotics share the pharmacological property of dopamine receptor antagonism–agents that increase synaptic dopamine can result in psychosis (cocaine, amphetamines).
Mesocortical dopaminergic dysregulation produces negative symptoms like social isolation and poor hygiene
Mesolimbic dopaminergic dysregulation produces positive symptoms like delusions and perceptual disturbances
Nigrostriatal dopaminergic dysregulation produces dystonia, akathisia, and Parkinson’s like symptoms.
Tuberoinfundibular dopaminergic dysregulation produces prolactin effects like galactorrhea and gynecomastia
Describe the difference between first and second generation antipsychotics and their side effects
First generation: typical/classical, can be high potency or low potency but have antihistamine, antiadrenergic, and anticholinergic effects
- Antihistaminic side effects: weight gain
- Anticholinergic side effects: delirium, blurry vision, xerostomia, constipation, urinary retention
- Antiadrenergic side effects: inability to regulate BP and arrhythmias
Second generation: atypical, block the D2 receptor and the 5-HT receptor. Not more effective than typicals but are better tolerated
- Side effects: weight gain, blood glucose dysregulation, metabolic syndrome
- Mood-stabilizing, antidepressant, and anxiolytic effects
Which drugs are shown to decrease suicide risk?
Clozapine and lithium, but clozapine can cause agranulocytosis so blood count must be watched
What do antidepressants do? What classes exist?
Antidepressants enhance monoamines
MAO inhibitors: dietary restriction to avoid hypertensive crisis (tyramine)
Tricyclic antidepressants: fatal in overdoses, cholinergic side effects
Serotonin reuptake inhibitors: safest and best tolerated
Serotonin norepinephrine reuptake inhibitors: used to treat comorbid pain syndrome
Antidepressants do not make people suicidal but may unmask a preexisting suicidal tendency
What are lithium and mood stabilizers used to treat?
