Psychopharmacology – Antipsychotics and Antidepressants Flashcards
Psychopharmacology – Antipsychotics and Antidepressants
Usage statistics
In the United States, approximately 1 in 6 adults filled prescriptions for psychiatric drugs in 2013, with antidepressants being the most commonly prescribed type (12%), followed by anxiolytics, sedatives, and hypnotics (8.3%), and antipsychotics (1.6%).
Antipsychotics:
First-Generation Antipsychotics (FGAs):
Also known as traditional or conventional antipsychotics.
Used to treat schizophrenia and other psychotic disorders.
More effective for positive symptoms of schizophrenia.
Mechanism: Primarily block dopamine (especially D2) receptors.
First-Generation Antipsychotics (FGAs) Examples
Examples: Chlorpromazine (Thorazine), haloperidol (Haldol), thioridazine (Mellaril), fluphenazine (Prolixin).
First-Generation Antipsychotics (FGAs) - Side effects
Anticholinergic Side Effects: Dry mouth, blurred vision, urinary retention, constipation, tachycardia.
Extrapyramidal Side Effects: Parkinsonism, dystonia, akathisia, tardive dyskinesia.
Neuroleptic Malignant Syndrome (NMS): Rare and life-threatening; symptoms include muscle rigidity, fever, autonomic dysfunction, altered mental state.
Management of tardive dyskinesia
Management of tardive dyskinesia involves gradually withdrawing the drug, administering benzodiazepines, or switching to second-generation antipsychotics. Neuroleptic malignant syndrome requires immediate discontinuation of the drug and supportive therapy.
Second-Generation Antipsychotics (SGAs)
Also known as atypical antipsychotics, SGAs include clozapine (Clozaril), risperidone (Risperdal), olanzapine (Zyprexa), quetiapine (Seroquel), and aripiprazole (Abilify).
Second-Generation Antipsychotics (SGAs)
Uses
Treatment of schizophrenia and other psychotic disorders.
Some are FDA-approved as adjunctive treatments for major depressive disorder.
Second-Generation Antipsychotics (SGAs)
Efficacy
SGAs are as effective as or more effective than FGAs for treating positive symptoms of schizophrenia.
They are more effective than FGAs for treating negative symptoms, particularly clozapine.
SGAs may be effective when FGAs have been ineffective.
Second-Generation Antipsychotics (SGAs)
Mechanism
Primarily block dopamine receptors, especially D3 and D4, to alleviate positive symptoms.
Block serotonin receptors to alleviate negative and cognitive symptoms.
Second-Generation Antipsychotics (SGAs)
Side Effects
Less likely to cause extrapyramidal side effects compared to FGAs.
Can cause anticholinergic effects, neuroleptic malignant syndrome, and metabolic syndrome.
Metabolic syndrome includes weight gain, high blood pressure, insulin resistance, hyperglycemia, and increased risk for diabetes mellitus and heart disease.
Clozapine and other SGAs can cause agranulocytosis, a potentially life-threatening condition characterized by a dangerously low white blood cell count. Regular white blood cell monitoring is necessary
Antidepressants
The major antidepressants include the selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), norepinephrine dopamine reuptake inhibitors (NDRIs), tricyclic antidepressants (TCAs), and monoamine oxidase inhibitors (MAOIs).
Selective Serotonin Reuptake Inhibitors (SSRIs)
SSRIs include fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), paroxetine (Paxil), sertraline (Zoloft), and citalopram (Celexa).
SSRIs offer an effective and generally well-tolerated treatment option for various psychiatric disorders, but precautions should be taken to avoid potential side effects and drug interactions.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Uses
First-line pharmacological treatment for major depressive disorder and persistent depressive disorder.
Also used to treat premenstrual dysphoric disorder, obsessive-compulsive disorder (OCD), panic disorder, generalized anxiety disorder, post-traumatic stress disorder (PTSD), bulimia nervosa, and premature ejaculation.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Mechanism
Therapeutic effects primarily achieved by blocking the reuptake of serotonin at nerve synapses.
Fluoxetine may also increase levels of norepinephrine and dopamine.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Efficacy
Comparable efficacy to tricyclic antidepressants (TCAs) but with fewer side effects.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Advantages
Fewer side effects compared to TCAs.
Safer in overdose and for older adults.
Delayed onset of therapeutic effects (about two to four weeks).
Selective Serotonin Reuptake Inhibitors (SSRIs)
Side Effects
Mild anticholinergic effects.
Gastrointestinal disturbances.
Insomnia.
Anxiety.
Sexual dysfunction.
Discontinuation syndrome upon abrupt cessation.
Potential for serotonin syndrome when combined with MAOIs, lithium, or other serotonergic drugs.
Selective Serotonin Reuptake Inhibitors (SSRIs)
Serotonin Syndrome
Potentially fatal condition characterized by extreme agitation, confusion, autonomic instability, hyperthermia, tremor, seizures, and delirium.
Requires immediate withdrawal of serotonergic drugs and appropriate medical interventions.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)
SNRIs include venlafaxine (Effexor), duloxetine (Cymbalta), and desvenlafaxine (Pristiq).
SNRIs offer an effective alternative to SSRIs for the treatment of various psychiatric disorders, but caution is needed regarding potential side effects and contraindications, particularly in patients with cardiovascular issues.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)
Uses
Treatment of major depressive disorder.
Management of social anxiety disorder.
Relief of neuropathic pain and other pain disorders.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)
Mechanism
Inhibition of the reuptake of both serotonin and norepinephrine at synapses.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)
Efficacy
Similar efficacy to SSRIs, with some evidence suggesting they may be more effective for severe depression.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)
Side Effects
Similar to SSRIs, including mild anticholinergic effects, gastrointestinal disturbances, insomnia, anxiety, sexual dysfunction.
Discontinuation syndrome upon abrupt cessation.
Potential for serotonin syndrome when combined with other serotonergic drugs.
May elevate blood pressure due to effects on norepinephrine, potentially contraindicated in patients with hypertension or heart problems.
Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)
NDRIs include bupropion (Wellbutrin, Zyban).
Bupropion offers unique advantages compared to other antidepressants, making it a valuable option for patients who may not tolerate or respond well to other medications. However, caution is needed regarding the risk of seizures and other potential side effects.
Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)
Uses
Treatment of major depressive disorder.
Smoking cessation aid.
Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)
Mechanism
Inhibits the reuptake of both norepinephrine and dopamine at synapses.
Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)
Efficacy
Effective for treating depression and assisting with smoking cessation.
Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)
Side Effects
Skin rash.
Decreased appetite and weight loss.
Agitation.
Insomnia.
Dizziness.
Seizures (particularly at higher doses).
Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)
Advantages:
Few anticholinergic effects.
Does not cause sexual dysfunction.
Not cardiotoxic.
Tricyclic Antidepressants (TCAs)
TCAs include amitriptyline (Elavil), imipramine (Tofranil), clomipramine (Anafranil), nortriptyline (Pamelor), desipramine (Norpramin), and doxepin (Sinequan).
Tricyclic antidepressants are effective medications for various psychiatric and neurological conditions but require careful consideration of potential side effects and risks, especially in vulnerable patient populations.
Tricyclic Antidepressants (TCAs)
Uses
Major depressive disorder.
Panic disorder.
Obsessive-compulsive disorder (especially clomipramine).
Neuropathic pain (especially nortriptyline and amitriptyline).
Tricyclic Antidepressants (TCAs)
Mechanism
Inhibit the reuptake of norepinephrine, serotonin, and dopamine at synapses.
Tricyclic Antidepressants (TCAs)
Efficacy
Effective for treating depression, anxiety disorders, and neuropathic pain
Tricyclic Antidepressants (TCAs)
Side Effects
Cardiovascular effects (e.g., hypertension, tachycardia, orthostatic hypotension).
Anticholinergic effects (e.g., dry mouth, blurred vision, constipation, urinary retention).
Sedation.
Weight gain.
Sexual dysfunction.
Risk of overdose, which can be lethal due to cardiotoxic effects.
Tricyclic Antidepressants (TCAs)
Precautions
Caution required in patients with heart disease or suicidal tendencies due to the cardiotoxic and lethal potential in overdose.
Monoamine Oxidase Inhibitors (MAOIs):
MAOIs include phenelzine (Nardil), isocarboxazid (Marplan), and tranylcypromine (Parnate).
MAOIs can be effective antidepressants but require careful management due to their potential for serious interactions and side effects. They are typically reserved for use in patients who have not responded to other treatment options.
Monoamine Oxidase Inhibitors (MAOIs):
Uses
Treatment-resistant depression.
Atypical depression (characterized by reversed vegetative symptoms such as hypersomnia, increased appetite, and reactive dysphoria).
Monoamine Oxidase Inhibitors (MAOIs):
Mechanism
Inhibit the activity of monoamine oxidase enzyme, which deactivates norepinephrine, serotonin, and dopamine.
Increase levels of these neurotransmitters in the brain.
Monoamine Oxidase Inhibitors (MAOIs):
Efficacy
Effective for depression, particularly in patients who have not responded to other antidepressant medications.
Monoamine Oxidase Inhibitors (MAOIs):
Side Effects
Anticholinergic effects (e.g., dry mouth, blurred vision, constipation, urinary retention).
Orthostatic hypotension.
Sedation.
Sexual dysfunction.
Risk of hypertensive crisis when taken with certain foods or medications.
Monoamine Oxidase Inhibitors (MAOIs):
Precautions
Avoid foods high in tyramine (e.g., aged cheese and meat, soy products, beer, red wine, sauerkraut, fava beans, ripe bananas) and medications that can interact with MAOIs to prevent hypertensive crisis.
Monitor for signs of hypertensive crisis, including severe headache, neck stiffness, rapid heart rate, nausea, vomiting, sweating, sensitivity to light, confusion, and delirium.
