Psychotherapeutic Drugs: Antipsychotics and Antidepressants

Psychotherapeutic Drugs

• Antipsychotics:
  • Typical antipsychotics (e.g., haloperidol aka Haldol)
  • Atypical antipsychotics (e.g., clozapine aka Clozaril)
• Antidepressants:
  • Tricyclic antidepressants (TCAs) (e.g., amitriptyline aka Elavil)
  • Selective serotonin reuptake inhibitors (SSRIs) (e.g., fluoxetine aka Prozac)
  • Serotonin and norepi reuptake inhibitors (SNRIs) (e.g., venlafaxine aka Effexor)
  • Monoamine oxidase inhibitor (MAOIs) (e.g., phenelzine aka Nardil)
  • Other antidepressants (e.g., bupropion aka Wellbutrin)
• Mood stabilizers (e.g., lithium aka Lithobid)
• CNS stimulants (e.g., methylphenidate aka Ritalin)

Overview of Major Psychiatric Disorders

• Psychoses (e.g., schizophrenia): exhibit gross disturbances in comprehension of reality, hallucinations, and delusions
• Affective disorders (e.g., depression): emotional disturbances in which mood is low or high

Schizophrenia

• Most common form of psychosis (1% of the world's population)
• Hallmark symptoms: delusions, hallucinations, disorganized thinking, and emotional abnormalities
• Several forms: paranoid, disorganized, and catatonic forms

Extrapyramidal Symptoms (EPS)

• Drug-induced movement disorders with acute and tardive symptoms
• Symptoms include:
  • Dystonia: continuous spasms and muscle contractions
  • Akathisia: motor restlessness
  • Parkinsonism: characteristic symptoms like rigidity, bradykinesia, and tremor
  • Tardive dyskinesia: irregular, jerky movements

Pharmacologic Effects of Antipsychotics

• Alleviate symptoms of schizophrenia by blocking dopamine and serotonin receptors
• Receptors are blocked immediately, but the drug still takes a few weeks to improve symptoms
• Antipsychotic drugs produce three time-dependent changes in dopamine neurotransmission:
  1. Increase in dopamine synthesis, release, and metabolism
  2. Continued blockade leads to inactivation of dopaminergic neurons producing a depolarization blockade
  3. Eventually leads to dopamine receptor up-regulation and supersensitivity to dopamine agonists

Neuroleptic Malignant Syndrome (NMS)

• Severe form of drug toxicity, occurs in 0.5 to 1% of patients treated with antipsychotics
• Life-threatening, characterized by muscle rigidity, elevated T, AMS, and autonomic dysfunction
• Managed by immediately discontinuing treatment and administering dantrolene to prevent further muscular abnormalities

Typical Antipsychotics

• Mechanism: exert therapeutic effect as a result of D2 receptor antagonism
• Adverse effects:
  • Akathisia: motor restlessness
  • Pseudoparkinsonism: rigidity, bradykinesia, and tremor
  • Dystonia: abnormal muscle tension of neck and facial muscles

Atypical Antipsychotics

• Clozapine aka Clozaril
• Olanzapine aka Zyprexa
• Quetiapine aka Seroquel
• Risperidone aka Risperdal
• Aripiprazole aka Abilify

Mechanism of Atypical Antipsychotics

• Olanzapine: chemical analogue of clozapine, has similar properties but fewer autonomic side effects
• Aripiprazole: partial dopamine agonist at dopamine and 5-HT1A receptors, but antagonizes 5-HT2A receptors

Affective Disorders

• Bipolar disorder:
  • Manic phase: elevated mood, inflated self-esteem, increased talking, racing thoughts, increased social or work activity, and decreased need for sleep
  • Occurs just before or just after a depressive episode
  • Episodes can last several weeks or months

Antidepressant Drugs

• Indications: depression, eating disorders, anxiety disorders, fibromyalgia, autism, and premenstrual dysphoric disorder
• Mechanism:
  • TCAs: block neuronal reuptake of norepi and serotonin by blocking norepi transporter (NET) and serotonin transporter (SERT)
  • SSRIs: selectively block serotonin reuptake, increasing serotonin levels in the synapse
  • SNRIs: block both serotonin and norepi reuptake transporters
  • MAOIs: inhibit monoamine oxidase, increasing levels of serotonin, norepi, and dopamine in the synapse

This quiz covers different types of psychotherapeutic drugs including antipsychotics, antidepressants, and their subclasses. Learn about typical and atypical antipsychotics, tricyclic antidepressants, SSRIs, SNRIs, and MAOIs.