Psychiatric Medications Study Guide

Q: What is serotonin syndrome and how is it different from neuroleptic malignant syndrome?

Serotonin syndrome: too much serotonin from SSRIs combined with other serotonergic drugs (MAOIs, triptans, tramadol, St. John's wort). Triad: mental status changes, autonomic instability (sweating, tachycardia, hypertension), neuromuscular hyperactivity (clonus, tremor, hyperreflexia). NMS: reaction to antipsychotics. Triad: hyperthermia (very high), severe muscle rigidity ("lead-pipe"), altered consciousness, autonomic instability. Both: stop the offending drug, supportive care. NMS may need dantrolene, bromocriptine.

Q: What are the side effects of typical vs atypical antipsychotics?

Typical (first-generation) — haloperidol, chlorpromazine, fluphenazine. Mostly block dopamine. High risk of extrapyramidal symptoms (EPS): acute dystonia, akathisia, parkinsonism, tardive dyskinesia. Treat acute dystonia with IM benztropine or diphenhydramine. Atypical (second-generation) — risperidone, olanzapine, quetiapine, aripiprazole, clozapine. Block both serotonin and dopamine. Lower EPS risk but higher metabolic side effects: weight gain, hyperglycemia, dyslipidemia. Clozapine: risk of agranulocytosis — weekly CBC monitoring.

Q: Why does lithium require regular blood monitoring?

Lithium has a narrow therapeutic range: 0.6–1.2 mEq/L for maintenance; toxicity at > 1.5; severe at > 2.0. Toxicity can be fatal. Signs: tremor, GI upset, ataxia, slurred speech, confusion, seizures, dysrhythmias, coma. Risk factors for toxicity: dehydration, sodium loss (low-sodium diet, sweating, diuretics), kidney impairment, drug interactions (NSAIDs, ACE inhibitors). Maintain consistent sodium and fluid intake (2–3 L water/day). Check levels every 5–7 days early, then every 3–6 months.

Q: What is the difference between SSRIs, SNRIs, and TCAs?

SSRIs (-pram/-line: sertraline, fluoxetine, citalopram, escitalopram) — first-line for depression and anxiety. Fewer side effects. Onset 2–6 weeks. Watch for serotonin syndrome and discontinuation syndrome. SNRIs (venlafaxine, duloxetine) — also affect norepinephrine; useful for depression with pain. TCAs (amitriptyline, nortriptyline, imipramine) — older, more side effects (anticholinergic: dry mouth, urinary retention, constipation, blurred vision; cardiotoxic in overdose). Used for depression, neuropathic pain, migraines.

Q: What is the appropriate teaching for a patient starting benzodiazepines?

(1) Take exactly as prescribed; do not stop abruptly — risk of withdrawal seizures with long-term use. (2) Avoid alcohol and other CNS depressants (opioids — overdose risk). (3) High dependence and tolerance potential — typically prescribed short-term. (4) May impair driving and operating machinery. (5) Take with food if GI upset. (6) Avoid in pregnancy (especially first trimester) — risk of cleft palate. (7) Antidote: flumazenil. Common drugs: lorazepam, diazepam, alprazolam.

Psychiatric Medications Overview

Five major drug classes work primarily by adjusting neurotransmitter activity in the brain.

Psychiatric medications work primarily by adjusting the activity of neurotransmitters in the brain. Each major class targets different systems — serotonin, norepinephrine, dopamine, and GABA — to relieve specific symptoms. The most heavily tested concept across psychiatric pharmacology is recognizing serious adverse effects and the nursing implications for safe administration.

Five Major Classes

Antidepressants: Depression, anxiety, PTSD, OCD, panic — increase serotonin, norepinephrine, and/or dopamine
Mood Stabilizers: Bipolar disorder — both depression and mania. Various mechanisms; lithium mechanism not fully understood.
Antipsychotics: Schizophrenia, psychosis, severe mania, agitation — block dopamine receptors (mainly D2)
Anxiolytics: Acute anxiety, panic, alcohol withdrawal, seizures — enhance GABA (benzodiazepines); serotonin 1A partial agonist (buspirone)
Stimulants: ADHD, narcolepsy — increase dopamine and norepinephrine

Key Neurotransmitters

Serotonin (5-HT) — mood, anxiety, sleep, appetite. Low levels linked to depression and anxiety.
Norepinephrine — alertness, attention, mood. Low levels in depression.
Dopamine — reward, motivation, motor control. Excess linked to psychosis; deficiency linked to depression and Parkinsonism.
GABA — primary inhibitory neurotransmitter. Enhanced by benzodiazepines, barbiturates, alcohol.
Acetylcholine — memory, cognition. Many psychiatric medications cause anticholinergic side effects.

Universal Principle: Onset Takes Time

Most antidepressants, mood stabilizers, and antipsychotics take 4-6 weeks to reach full therapeutic effect. The nurse must teach clients to continue taking the medication consistently even if they do not feel better immediately. Stopping early is one of the most common reasons for treatment failure.

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SSRIs & SNRIs — First-Line Antidepressants

The most commonly prescribed psychiatric medications. Tested heavily.

SSRIs (Selective Serotonin Reuptake Inhibitors)

SertralineZoloft: Often first choice; well-tolerated; safe in pregnancy and breastfeeding
FluoxetineProzac: Long half-life; less risk of discontinuation syndrome
EscitalopramLexapro: Well-tolerated; minimal drug interactions
CitalopramCelexa: Risk of QT prolongation at higher doses
ParoxetinePaxil: Most anticholinergic SSRI; significant discontinuation syndrome
FluvoxamineLuvox: Often used for OCD

SNRIs (Serotonin-Norepinephrine Reuptake Inhibitors)

VenlafaxineEffexor: Can raise blood pressure; significant discontinuation syndrome
DuloxetineCymbalta: Also approved for neuropathic pain, fibromyalgia, chronic musculoskeletal pain
DesvenlafaxinePristiq: Active metabolite of venlafaxine

Uses

Major depressive disorder (first-line)
Generalized anxiety disorder
Panic disorder
OCD (often higher doses required)
PTSD (sertraline and paroxetine FDA-approved)
Social anxiety disorder
Premenstrual dysphoric disorder

Side Effects

GI: Nausea, diarrhea (usually improves after 1-2 weeks)
Sexual: Decreased libido, anorgasmia, erectile dysfunction (often persistent)
Sleep: Insomnia OR sedation (varies by drug and client)
Weight changes: Variable
Headache, dizziness
Increased anxiety in the first 1-2 weeks (especially in panic disorder)
Bleeding risk when combined with NSAIDs or anticoagulants
Hyponatremia — SIADH especially in older adults

Critical Nursing Implications

Onset: 4-6 weeks for full therapeutic effect
Black box warning: Increased suicidal ideation in children, adolescents, and young adults under 25
Suicide risk increases in weeks 1-4 — energy returns before depression lifts. Assess suicide risk frequently during this period.
Do NOT discontinue abruptly — causes discontinuation syndrome (flu-like symptoms, dizziness, "brain zaps," irritability)
Avoid alcohol — can worsen depression and interact
Teach not to combine with St. John's Wort, MAOIs, or tramadol — risk of serotonin syndrome

Black Box Warning: Suicide Risk in Young People

The FDA requires a black box warning on SSRIs and SNRIs regarding increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults under age 25. This is highest in the first 1-4 weeks of treatment. Monitor closely — the medication is restoring energy and motivation before depressive thoughts lift, which can give clients the energy to act on suicidal thoughts they were previously too depressed to act on.

TCAs & Atypical Antidepressants

Older and unique antidepressants — know the key adverse effects.

Tricyclic Antidepressants (TCAs)

AmitriptylineElavil: Highly anticholinergic; sedating; used for neuropathy and migraine prevention
NortriptylinePamelor: Less sedating than amitriptyline
ImipramineTofranil: Also used for enuresis (bedwetting) in children
DesipramineNorpramin: Least sedating TCA
ClomipramineAnafranil: Effective for OCD

TCA Side Effects (Mnemonic: "Cardiac, Convulsions, Coma")

Anticholinergic effects: Dry mouth, blurred vision, urinary retention, constipation, drowsiness ("Red as a beet, dry as a bone, blind as a bat, mad as a hatter")
Orthostatic hypotension
Sedation — can be helpful for clients with insomnia
Cardiac toxicity — QT prolongation, dysrhythmias, conduction abnormalities
Weight gain
Sexual dysfunction
Lower seizure threshold

TCA Overdose Is Often Fatal

TCAs have a narrow therapeutic index. Overdose causes the "3 Cs": Cardiac dysrhythmias, Convulsions, Coma. Even a 7-10 day supply can be fatal. This is why TCAs are rarely first-line for depressed clients with suicidal ideation — they are too dangerous to have on hand. SSRIs are preferred for safety.

Atypical Antidepressants

BupropionWellbutrin, Zyban: Norepinephrine-dopamine reuptake inhibitor. No sexual side effects. Helps with smoking cessation. Contraindicated in seizure disorders, eating disorders. Lowers seizure threshold.
MirtazapineRemeron: Increases NE and serotonin via different mechanism. Causes significant weight gain and sedation — useful in depressed clients with weight loss and insomnia. Often given at bedtime.
TrazodoneDesyrel: Highly sedating. Often used in low doses for insomnia. Risk of priapism (painful prolonged erection) — teach men to seek emergency care if erection lasts more than 4 hours.
VilazodoneViibryd: SSRI plus 5-HT1A partial agonist. Less sexual dysfunction than typical SSRIs.
VortioxetineTrintellix: Newer; mixed serotonergic activity. Used for depression with cognitive symptoms.

MAOIs & the Tyramine-Restricted Diet

The least commonly prescribed antidepressants but heavily tested.

Common MAOIs

Phenelzine (Nardil)
Tranylcypromine (Parnate)
Isocarboxazid (Marplan)
Selegiline transdermal (Emsam) — low doses have less dietary restriction

How MAOIs Work

MAOIs inhibit monoamine oxidase, an enzyme that breaks down norepinephrine, serotonin, dopamine, and tyramine. When tyramine is not broken down, it can cause a massive release of norepinephrine, leading to hypertensive crisis.

Tyramine-Restricted Diet (MEMORIZE)

Aged cheeses (cheddar, blue, parmesan, Swiss, Brie): High tyramine from aging process
Cured and smoked meats (salami, pepperoni, summer sausage, smoked fish): Curing increases tyramine content
Aged or smoked fish (pickled herring, anchovies): High tyramine
Fermented soy products (soy sauce, miso, tempeh, fermented tofu/bean curd): Fermentation increases tyramine. Some MAOI labels also advise avoiding most soy products, including plain tofu — follow the prescriber/dietitian's specific list
Red wine, beer (especially tap/unpasteurized), vermouth: Fermentation produces tyramine
Sauerkraut, kimchi, other fermented foods: Fermentation
Broad bean pods (fava beans): Contain dopamine
Concentrated yeast extracts (Marmite, Vegemite): Very high tyramine
Overripe or spoiled foods: Bacterial decomposition produces tyramine

MAOI + Tyramine = Hypertensive Crisis

Severe occipital headache (classic first sign), stiff neck, sharply elevated blood pressure, palpitations, tachycardia, sweating, flushing, nausea, vomiting, risk of stroke or MI. Treatment: emergency hypertensive crisis management; phentolamine or other rapid-acting antihypertensives. Hold the MAOI.

Drug Interactions with MAOIs

SSRIs, SNRIs, TCAs — risk of serotonin syndrome. Requires 2-5 week washout period when switching.
Sympathomimetics — pseudoephedrine (Sudafed), epinephrine, decongestants
Tramadol, meperidine — serotonin syndrome risk
Triptans (sumatriptan) — serotonin syndrome risk
St. John's Wort
Stimulants

Nursing Teaching

Provide a written list of tyramine-containing foods
Teach to read food labels carefully
Avoid OTC cold and allergy medications without checking
Carry a medical alert card identifying use of MAOI
Restrictions continue for 2 weeks after stopping the medication
Report any severe headache immediately

Mood Stabilizers & Lithium

For bipolar disorder — lithium has a narrow therapeutic window requiring close monitoring.

Lithium — The Classic Mood Stabilizer

Therapeutic range: 0.6-1.2 mEq/L for maintenance; up to 1.5 mEq/L for acute mania
Onset: 1-3 weeks for full antimanic effect
Narrow therapeutic window — requires frequent blood level monitoring (weekly initially, then every few months)
Excreted unchanged through the kidneys — competes with sodium for reabsorption

Lithium Toxicity Levels

Ranges vary by lab, facility, and textbook — for exams, use the range given in the question. See the full NCLEX-PN lab-value reference & sources →

0.6–1.2therapeutic: Mild tremor, polyuria, polydipsia, mild GI upset are normal/expected at lower end
1.5–2.0mild toxicity: Increased tremor, GI symptoms (nausea, vomiting, diarrhea), drowsiness, mild ataxia, slurred speech, muscle weakness
2.0–2.5moderate toxicity: Severe ataxia, confusion, blurred vision, dysrhythmias, hypotension
> 2.5severe — life-threatening: Seizures, coma, cardiovascular collapse, death. Requires hemodialysis.

Lithium and Sodium: The Critical Connection

Lithium is handled by the kidneys like sodium. If sodium intake decreases (low-salt diet, sweating, diarrhea, vomiting, diuretic use), the kidneys retain MORE lithium to compensate, raising the lithium level into the toxic range. Teach: maintain consistent sodium intake, drink 2-3 liters of water daily, increase fluids during hot weather/illness, avoid NSAIDs and thiazide diuretics, report tremor/GI upset/ataxia/confusion immediately, get regular lithium levels drawn 12 hours after last dose.

Other Lithium Side Effects to Monitor

Hypothyroidism — monitor TSH
Nephrogenic diabetes insipidus — polyuria, polydipsia
Renal impairment — monitor creatinine
Cardiac effects — can cause dysrhythmias
Teratogenic — causes cardiac defects (Ebstein anomaly). Avoid in pregnancy.
Weight gain

Anticonvulsant Mood Stabilizers

Valproate (Depakote)50–100 mcg/mL (up to ~125 in acute mania): Monitor liver function and platelets. Teratogenic — neural tube defects (spina bifida). Hair loss, weight gain.
Carbamazepine (Tegretol)4–12 mcg/mL: Risk of agranulocytosis and aplastic anemia — monitor CBC. Avoid grapefruit juice. Many drug interactions (induces CYP enzymes).
Lamotrigine (Lamictal)not routinely monitored: Risk of Stevens-Johnson syndrome — rash requires IMMEDIATE discontinuation. Titrate slowly to reduce risk.
Oxcarbazepine (Trileptal)not routinely monitored: Similar to carbamazepine but fewer interactions. Risk of hyponatremia.

Antipsychotics: Typical vs Atypical

Block dopamine receptors to treat psychosis — but with significant adverse effect profiles.

Typical (First-Generation) Antipsychotics

High-PotencyHaloperidol (Haldol), fluphenazine, pimozide, thiothixene: HIGHER risk of EPS. Less sedation. Less anticholinergic effects.
Low-PotencyChlorpromazine (Thorazine), thioridazine: LESS EPS. More sedation, anticholinergic effects, orthostatic hypotension. Chlorpromazine causes photosensitivity.

Typical antipsychotics primarily treat positive symptoms (hallucinations, delusions). They have HIGH risk of extrapyramidal symptoms (EPS), tardive dyskinesia, and neuroleptic malignant syndrome (NMS).

Atypical (Second-Generation) Antipsychotics — First-Line

RisperidoneRisperdal: Most EPS risk of the atypicals at higher doses. Available as long-acting injection (Consta).
OlanzapineZyprexa: HIGH risk of metabolic syndrome (weight gain, hyperglycemia, dyslipidemia). Effective for acute mania.
QuetiapineSeroquel: Highly sedating. Often used for bipolar depression and insomnia (low dose).
AripiprazoleAbilify: Partial dopamine agonist (different mechanism). Less weight gain. Less sedation. Available as monthly injection.
ZiprasidoneGeodon: Less weight gain. Risk of QT prolongation — baseline ECG recommended.
ClozapineClozaril: Most effective for treatment-resistant schizophrenia. Risk of agranulocytosis — requires weekly CBC monitoring. Lower EPS but high sedation, weight gain, drooling, seizure risk.
PaliperidoneInvega: Active metabolite of risperidone. Long-acting injection (Sustenna) available.
LurasidoneLatuda: Less weight gain. Must be taken WITH food (at least 350 calories).

Atypical Antipsychotic Side Effects

Metabolic syndrome — weight gain, hyperglycemia, dyslipidemia, hypertension. Monitor fasting glucose, lipids, weight, BP.
Sedation
Anticholinergic effects
Orthostatic hypotension
Hyperprolactinemia — galactorrhea, gynecomastia, amenorrhea, sexual dysfunction (especially risperidone)
QT prolongation (especially ziprasidone)
EPS — LESS common than with typicals, but still possible (especially risperidone at high doses)

Clozapine Monitoring Is Strict

Weekly CBC for the first 6 months, then every 2 weeks for next 6 months, then monthly. Monitor the ANC, not the WBC: clozapine generally is not started if baseline ANC is below 1,500/mm3. During therapy, ANC 1,000–1,499 usually means continue with increased monitoring; interrupt for ANC 500–999 and resume when ANC is ≥1,000; discontinue for ANC below 500. The FDA has removed the clozapine REMS requirement. Teach client to report sore throat, fever, lethargy, mucous membrane ulcers immediately. Risk of agranulocytosis (life-threatening drop in WBCs). Also increased risk of seizures, myocarditis, severe constipation, hypersalivation. Reserved for treatment-resistant schizophrenia (failed 2+ other antipsychotics).

Long-Acting Injectable Antipsychotics

Examples: Haloperidol decanoate, fluphenazine decanoate, paliperidone (Invega Sustenna), risperidone (Risperdal Consta), aripiprazole (Abilify Maintena), olanzapine (Zyprexa Relprevv)
Administered IM every 2 weeks to monthly
Improve medication adherence — major issue in schizophrenia
Reduce relapse and rehospitalization

EPS, NMS, & Tardive Dyskinesia

The most critical antipsychotic adverse effects — recognition saves lives.

Extrapyramidal Symptoms (EPS)

Acute Dystoniahours to days: Sudden painful muscle spasms — face, neck, tongue, back. Torticollis, oculogyric crisis (eyes rolled back), tongue protrusion, laryngospasm (EMERGENCY). Treatment: IM benztropine (Cogentin) or diphenhydramine (Benadryl).
Akathisiadays to weeks: Severe restlessness, inability to sit still, pacing. Client describes feeling like "crawling out of skin." Treatment: reduce dose, switch medication, add beta-blocker (propranolol) or benztropine.
Pseudoparkinsonismweeks to months: Resting tremor, muscle rigidity, shuffling gait, bradykinesia, mask-like facial expression, drooling. Treatment: anticholinergics (benztropine, trihexyphenidyl), amantadine, dose reduction.
Tardive Dyskinesia (TD)MONTHS TO YEARS — OFTEN PERMANENT: Involuntary repetitive movements — lip smacking, tongue protrusion, facial grimacing, finger movements. Discontinue if possible. May be irreversible. Switch to clozapine. Valbenazine or deutetrabenazine are FDA-approved.

Tardive Dyskinesia May Be Permanent

Unlike other EPS, TD often does NOT resolve when the antipsychotic is stopped. Use the Abnormal Involuntary Movement Scale (AIMS) to screen every 3-6 months. Risk factors include long-term typical antipsychotic use, older age, female sex, and high doses. Early recognition is critical — once established, TD may be irreversible.

Neuroleptic Malignant Syndrome (NMS) — MEDICAL EMERGENCY

NMS: Four Cardinal Signs

(1) Hyperthermia — severe fever often above 104°F. (2) Severe muscle rigidity — "lead pipe" rigidity. (3) Altered mental status — confusion, stupor, coma. (4) Autonomic instability — unstable BP, tachycardia, diaphoresis, tachypnea. Lab findings: elevated CK (rhabdomyolysis), elevated WBC, electrolyte abnormalities. Mortality: 10-20% without treatment.

NMS Nursing Care

STOP the antipsychotic immediately
Notify provider — medical emergency
Transfer to ICU for supportive care
Cooling measures — cooling blankets, antipyretics, IV fluids
IV fluids — prevent kidney damage from rhabdomyolysis
Medications: dantrolene (muscle relaxant), bromocriptine (dopamine agonist)
Continuous vital signs
Monitor renal function

Benzodiazepines & Other Anxiolytics

For acute anxiety, panic, alcohol withdrawal, seizures — but with significant risks.

Benzodiazepines

AlprazolamXanax · rapid/short: Panic attacks, acute anxiety. High abuse potential.
LorazepamAtivan · rapid/short: Alcohol withdrawal (safer in liver disease), acute anxiety, status epilepticus
DiazepamValium · rapid/long: Alcohol withdrawal, muscle spasm, seizures, anxiety
ClonazepamKlonopin · slow/long: Panic disorder, seizures
ChlordiazepoxideLibrium · slow/long: Alcohol withdrawal (commonly used)
MidazolamVersed · rapid/short: Pre-procedure sedation, status epilepticus

Benzodiazepine Adverse Effects

Sedation, drowsiness
Dizziness, ataxia — fall risk especially in older adults
Paradoxical agitation — especially in elderly and children
Memory impairment, confusion
Respiratory depression — especially with opioids or alcohol (most important adverse effect)
Tolerance and dependence — develop within weeks
Withdrawal can be life-threatening — seizures, similar to alcohol withdrawal

Benzodiazepine Cautions

Intended for short-term use only (2-4 weeks). NEVER stop abruptly after extended use — risk of withdrawal seizures. Avoid combining with opioids or alcohol — can cause fatal respiratory depression. Increased fall risk in older adults — on Beers criteria list to avoid. Antidote for overdose: Flumazenil (Romazicon) — use cautiously, can precipitate seizures in dependent clients.

Non-Benzodiazepine Anxiolytics

BuspironeBuspar: 5-HT1A partial agonist. Onset: 2-4 weeks — NOT for acute anxiety. No sedation, no respiratory depression, no dependence, no withdrawal. Good choice for clients with substance use history.
HydroxyzineVistaril, Atarax: Antihistamine with anxiolytic effects. Used for acute anxiety, pruritus. Sedating. No dependence risk.
Beta-blockersPropranolol (Inderal): Reduce physical symptoms of anxiety (tremor, tachycardia). Used for performance anxiety.

Z-Drugs (Sedative-Hypnotics for Sleep)

Zolpidem (Ambien), zaleplon (Sonata), eszopiclone (Lunesta)
Act on GABA receptors like benzodiazepines but more sleep-selective
Risk of complex sleep behaviors — sleepwalking, sleep-driving, sleep-eating
Black box warning for these complex behaviors
Take on empty stomach, only when prepared to sleep 7-8 hours

Serotonin Syndrome & Key Comparisons

Critical safety content — know how to recognize and differentiate these emergencies.

Serotonin Syndrome: Life-Threatening Drug Reaction

Caused by EXCESS serotonin from combining serotonergic medications: SSRIs + MAOIs (NEVER combine; require 2-5 week washout), SSRIs + St. John's Wort, SSRIs + tramadol/meperidine/fentanyl, SSRIs + triptans (sumatriptan), SSRIs + linezolid, SSRIs + MDMA or other illicit serotonergic drugs.

Symptoms (Mnemonic: "HARMED")

Hyperreflexia, clonus, tremor
Agitation, restlessness, confusion
Rigidity (less severe than NMS)
Myoclonus (muscle twitching)
Excessive sweating (diaphoresis), hyperthermia
Diarrhea, dilated pupils, tachycardia, hypertension

Treatment

Stop ALL serotonergic medications
Supportive care
Cooling, IV fluids
Benzodiazepines for agitation and muscle activity
Cyproheptadine — serotonin antagonist
Severe cases require ICU care

NMS vs Serotonin Syndrome — Comparison

Cause: NMS: Antipsychotics (dopamine blockade) | SS: Excess serotonin (serotonergic medications)
Onset: NMS: Slow — days to weeks | SS: Rapid — hours
Muscle findings: NMS: "LEAD PIPE" rigidity | SS: Hyperreflexia, clonus, less severe rigidity
Pupils: NMS: Normal | SS: DILATED
Bowel sounds: NMS: Normal or decreased | SS: HYPERACTIVE (diarrhea)
Treatment: NMS: Stop antipsychotic, dantrolene, bromocriptine | SS: Stop serotonergic drugs, cyproheptadine, supportive care

Antidotes Reference for Psychiatric Medications

Benzodiazepines: Flumazenil (Romazicon) — IV; can precipitate seizures in dependent clients
Opioids: Naloxone (Narcan) — IM, IV, or intranasal; short-acting, may need repeat doses
TCA overdose: Sodium bicarbonate — for cardiac toxicity (QRS widening, dysrhythmias)
Serotonin Syndrome: Cyproheptadine — serotonin antagonist
NMS: Dantrolene, bromocriptine — plus supportive ICU care
Anticholinergic toxicity: Physostigmine — for severe toxicity only
Lithium toxicity: Hemodialysis — for severe toxicity (level > 2.5 or symptomatic)

? What is the key difference in muscle findings between NMS and serotonin syndrome?

NMS = "lead pipe" rigidity (severe, generalized). Serotonin syndrome = hyperreflexia and clonus (the muscles are over-reactive, not uniformly rigid). Also: SS pupils are dilated and bowel sounds are hyperactive — NMS has normal pupils and normal/decreased bowel sounds.

Frequently Asked Questions

Common student questions on this topic.

What is serotonin syndrome and how is it different from neuroleptic malignant syndrome?

Serotonin syndrome: too much serotonin from SSRIs combined with other serotonergic drugs (MAOIs, triptans, tramadol, St. John's wort). Triad: mental status changes, autonomic instability (sweating, tachycardia, hypertension), neuromuscular hyperactivity (clonus, tremor, hyperreflexia). NMS: reaction to antipsychotics. Triad: hyperthermia (very high), severe muscle rigidity ("lead-pipe"), altered consciousness, autonomic instability. Both: stop the offending drug, supportive care. NMS may need dantrolene, bromocriptine.

What are the side effects of typical vs atypical antipsychotics?

Typical (first-generation) — haloperidol, chlorpromazine, fluphenazine. Mostly block dopamine. High risk of extrapyramidal symptoms (EPS): acute dystonia, akathisia, parkinsonism, tardive dyskinesia. Treat acute dystonia with IM benztropine or diphenhydramine. Atypical (second-generation) — risperidone, olanzapine, quetiapine, aripiprazole, clozapine. Block both serotonin and dopamine. Lower EPS risk but higher metabolic side effects: weight gain, hyperglycemia, dyslipidemia. Clozapine: risk of agranulocytosis — weekly CBC monitoring.

Why does lithium require regular blood monitoring?

Lithium has a narrow therapeutic range: 0.6–1.2 mEq/L for maintenance; toxicity at > 1.5; severe at > 2.0. Toxicity can be fatal. Signs: tremor, GI upset, ataxia, slurred speech, confusion, seizures, dysrhythmias, coma. Risk factors for toxicity: dehydration, sodium loss (low-sodium diet, sweating, diuretics), kidney impairment, drug interactions (NSAIDs, ACE inhibitors). Maintain consistent sodium and fluid intake (2–3 L water/day). Check levels every 5–7 days early, then every 3–6 months.

What is the difference between SSRIs, SNRIs, and TCAs?

SSRIs (-pram/-line: sertraline, fluoxetine, citalopram, escitalopram) — first-line for depression and anxiety. Fewer side effects. Onset 2–6 weeks. Watch for serotonin syndrome and discontinuation syndrome. SNRIs (venlafaxine, duloxetine) — also affect norepinephrine; useful for depression with pain. TCAs (amitriptyline, nortriptyline, imipramine) — older, more side effects (anticholinergic: dry mouth, urinary retention, constipation, blurred vision; cardiotoxic in overdose). Used for depression, neuropathic pain, migraines.

Why are MAOIs avoided in modern practice?

Monoamine oxidase inhibitors (phenelzine, tranylcypromine) require a strict tyramine-free diet — eating aged cheeses, cured meats, fava beans, fermented foods, or red wine can cause a hypertensive crisis (sudden severe HTN, headache, stroke risk). Many drug interactions (any other serotonergic drug → serotonin syndrome). Requires 2-week washout before switching to another antidepressant. Reserved for treatment-resistant depression when other options have failed.

What is the appropriate teaching for a patient starting benzodiazepines?

(1) Take exactly as prescribed; do not stop abruptly — risk of withdrawal seizures with long-term use. (2) Avoid alcohol and other CNS depressants (opioids — overdose risk). (3) High dependence and tolerance potential — typically prescribed short-term. (4) May impair driving and operating machinery. (5) Take with food if GI upset. (6) Avoid in pregnancy (especially first trimester) — risk of cleft palate. (7) Antidote: flumazenil. Common drugs: lorazepam, diazepam, alprazolam.

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