Psychotropic Medications
Key Points
- Psychotropic medications act on neurotransmitters (serotonin, dopamine, GABA, norepinephrine) to treat mental health disorders
- Antidepressants (SSRIs/SNRIs): First-line for depression and most anxiety disorders; 2–4 weeks to therapeutic effect; watch for serotonin syndrome and suicidal ideation in early treatment
- Antipsychotics: First-gen → EPS/tardive dyskinesia; Second-gen (atypical) → metabolic syndrome; clozapine requires REMS monitoring for agranulocytosis
- Lithium: Narrow therapeutic index (0.6–1.2 mEq/L); monitor levels every 10–12 hours after last dose; NSAIDs and diuretics increase lithium toxicity risk
- Benzodiazepines: Schedule IV; GABA-A agonists; flumazenil reversal; NEVER abrupt discontinuation
- All psychotropic medications require monitoring for suicidal ideation — especially during initiation or dose changes
Neurotransmitter Basis
Psychotropic medications target imbalances in brain neurotransmitters:
| Neurotransmitter | Role | Deficiency/Excess | Drug Classes Targeting It |
|---|---|---|---|
| Serotonin (5-HT) | Mood, sleep, appetite | Deficiency → depression, anxiety | SSRIs, SNRIs, antipsychotics |
| Norepinephrine (NE) | Alertness, arousal | Excess → anxiety; deficiency → depression | SNRIs, TCAs, MAOIs |
| Dopamine | Reward, movement | Excess → psychosis; deficiency → EPS | Antipsychotics (block), antidepressants |
| GABA | Inhibitory (calming) | Deficiency → anxiety, seizures | Benzodiazepines, buspirone |
| Glutamate | Excitatory | Excess → mania, neurotoxicity | Lithium (reduces) |
Class 1: Antidepressants
First-line pharmacotherapy for major depressive disorder, anxiety disorders, OCD, PTSD, and panic disorder.
Onset: 2–4 weeks to therapeutic effect — patients must continue even if they feel no benefit initially.
Major Subclasses:
- SSRIs: Sertraline, fluoxetine, escitalopram — preferred first-line; block serotonin reuptake
- SNRIs: Venlafaxine, duloxetine — block serotonin + norepinephrine reuptake
- Trazodone (SARI): Commonly used off-label as sedative for insomnia
- TCAs: Amitriptyline, nortriptyline — high anticholinergic burden; lethal overdose risk
- MAOIs: Phenelzine, tranylcypromine — severe dietary and drug interactions (tyramine → hypertensive crisis)
Black Box Warning — Antidepressants and Suicidality
All antidepressants carry an FDA Black Box Warning for increased risk of suicidal thinking and behavior in children, adolescents, and young adults under age 24. Monitor closely during the first 1–4 weeks of treatment or dose changes.
See antidepressants for complete drug profiles, adverse effects, and nursing management.
Class 2: Antipsychotics
Used to treat schizophrenia, schizoaffective disorder, bipolar mania, and psychotic features of other disorders.
First-Generation (Typical) Antipsychotics
Mechanism: Block D2 (dopamine) receptors in the limbic system and basal ganglia.
Agents: Chlorpromazine (Thorazine), haloperidol (Haldol), perphenazine, fluphenazine.
Primary Adverse Effects:
- Extrapyramidal Symptoms (EPS): Akathisia (restlessness), dystonia (acute muscle contractions), parkinsonism (tremor, rigidity, bradykinesia)
- Tardive Dyskinesia (TD): Involuntary repetitive movements persisting ≥1 month (tongue thrusting, grimacing, lip smacking) — may be irreversible
- Anticholinergic effects (dry mouth, constipation, urinary retention), sedation
Second-Generation (Atypical) Antipsychotics
Mechanism: Block D2 + serotonin (5-HT2A) receptors → treat positive symptoms (hallucinations, delusions) AND negative symptoms (flat affect, social withdrawal) with less EPS risk.
Agents: Risperidone, olanzapine, quetiapine, ziprasidone, aripiprazole, paliperidone, lurasidone.
Primary Adverse Effects:
- Metabolic Syndrome: Weight gain, hyperglycemia, hypertension, elevated triglycerides — monitor weight, blood glucose, lipids
- QTc prolongation risk (ziprasidone > others) — baseline ECG recommended
- Orthostatic hypotension, sedation
Clozapine — Treatment-Resistant Schizophrenia
Indication: Reserved for schizophrenia unresponsive to ≥2 adequate antipsychotic trials.
Unique Risk: Agranulocytosis (potentially fatal) — requires REMS monitoring program with regular absolute neutrophil count (ANC) monitoring. Also associated with myocarditis risk.
Neuroleptic Malignant Syndrome (NMS)
Rare but life-threatening complication of antipsychotics: fever, severe muscle rigidity (“lead pipe”), altered consciousness, and autonomic instability. Immediately discontinue antipsychotic and provide supportive care.
Class 3: Mood Stabilizers
Used primarily for bipolar disorder (acute mania, maintenance, bipolar depression).
Lithium (Gold Standard)
Mechanism: Affects synthesis, release, and reuptake of multiple neurotransmitters — reduces excitatory neurotransmission (dopamine, glutamate) and increases inhibitory GABA transmission.
Narrow Therapeutic Index: Requires routine serum level monitoring.
- Blood levels drawn 10–12 hours after last dose
- Therapeutic range: 0.6–1.2 mEq/L (maintenance closer to 0.6)
- Toxicity levels and signs:
| Serum Level | Clinical Signs |
|---|---|
| 1.5–2.5 mEq/L | Lethargy, tremors, nausea, vomiting |
| 2.5–3.5 mEq/L | Confusion, agitation, delirium, tachycardia |
| >3.5 mEq/L | Coma, seizures, hyperthermia, hypotension |
Critical Drug Interactions: NSAIDs and diuretics increase lithium levels → toxicity; theophylline decreases lithium levels.
Nursing Key Points:
- Administer with food; maintain adequate hydration (1.5–3 L/day)
- Avoid sodium restriction — sodium depletion causes kidney to reabsorb lithium → toxicity
- Monitor kidney function and thyroid function (lithium causes hypothyroidism with long-term use)
- Contraindicated in pregnancy (cardiac teratogen) and renal failure
Anticonvulsant Mood Stabilizers
Used as adjuncts or alternatives to lithium in bipolar disorder:
- Valproic acid/divalproex sodium (Depakote): Acute mania; therapeutic range 50–125 mcg/mL; hepatotoxic
- Carbamazepine (Tegretol): Therapeutic range 4–12 mg/L; induces CYP450
- Lamotrigine (Lamictal): Bipolar depression maintenance; must titrate slowly to prevent Stevens-Johnson syndrome (severe rash)
See anticonvulsants for complete anticonvulsant drug profiles.
Class 4: Anxiolytics
Used for anxiety disorders, acute agitation, and panic.
- Benzodiazepines (lorazepam, alprazolam, diazepam): Schedule IV; GABA-A agonists; fast onset; reversal agent = flumazenil; NEVER stop abruptly; + opioids → Boxed Warning for respiratory depression
- Buspirone: Non-addictive alternative; serotonin 5-HT1A partial agonist; onset 2–4 weeks; no sedation
- SSRIs/SNRIs: First-line for chronic anxiety disorders
See anxiolytics for complete profiles.
Class 5: Sedative-Hypnotics
Used for insomnia when nonpharmacologic measures have failed.
- Z-drugs (zolpidem, eszopiclone, zaleplon): Schedule IV; GABA-A agonists; Beers Criteria — avoid in older adults
- Ramelteon: Melatonin MT1/MT2 agonist; NOT controlled; preferred in older adults
- Orexin antagonists (suvorexant): Schedule IV; suppress wakefulness drive
See sedative-hypnotics for complete profiles.
Nursing Assessment
Before Initiating Any Psychotropic Medication:
- Complete mental status exam including suicidal ideation
- Medication history: prior psychiatric medications and response
- Substance use history (interactions with CNS depressants)
- Physical exam: baseline weight, vital signs, metabolic panel (especially for antipsychotics)
- Pregnancy/breastfeeding status
Ongoing Monitoring:
- Suicidal ideation — especially first 1–4 weeks
- Medication adherence (psychotropic medications often discontinued prematurely)
- Adverse effects specific to each drug class (EPS, metabolic syndrome, lithium toxicity signs)
- Therapeutic drug levels where required (lithium, some anticonvulsants)
Patient Education:
- Do not stop medications abruptly without provider guidance
- Therapeutic effect takes time — set realistic expectations (2–4 weeks for antidepressants, 1–3 weeks for lithium)
- Report new or worsening suicidal thoughts, unusual behaviors, or severe adverse effects immediately
- Avoid alcohol and CNS depressants (especially with benzodiazepines)
Related Concepts
- antidepressants — SSRIs, SNRIs, TCAs, MAOIs with complete profiles
- anxiolytics — Benzodiazepines, buspirone, and SSRI/SNRI anxiolytic use
- sedative-hypnotics — Z-drugs, ramelteon, and orexin antagonists for insomnia
- anticonvulsants — Mood stabilizing anticonvulsants (valproate, lamotrigine)
- psychopharmacology — Psychiatric medication overview in mental health concepts
- substance-use-disorders — Benzodiazepine dependence and withdrawal management
- self-harm-and-suicide — Antidepressant Black Box Warning and suicidality monitoring
Self-Check
- A patient on lithium reports nausea, hand tremors, and excessive thirst. What do you suspect, and what serum level would indicate toxicity requiring immediate intervention?
- A patient started on an antipsychotic 2 months ago develops involuntary lip smacking and tongue thrusting. What extrapyramidal complication do you suspect, and what is the significance of its persistence?
- A provider orders clozapine for a patient with treatment-resistant schizophrenia. What mandatory monitoring program must be in place before dispensing?