Before We Start
Antipsychotics — managing psychosis, and managing the side effects that come with it
Antipsychotic medications are used to treat schizophrenia, bipolar disorder, and other conditions involving psychosis — hallucinations, delusions, and disorganized thinking. They are also used for agitation in dementia, nausea, and augmentation of antidepressants. First-generation antipsychotics (typicals) and second-generation (atypicals) have different side effect profiles — but both carry serious risks nurses must monitor for.
Two mnemonics cover this territory. ADAPT gives you the extrapyramidal side effects (EPS) — movement disorders caused by dopamine blockade. Lithium toxicity gets its own section because lithium is a uniquely dangerous mood stabilizer with a narrow therapeutic window.
💡 How Antipsychotics Work
Psychosis involves excess dopamine activity in certain brain pathways. Antipsychotics block dopamine D2 receptors — reducing that excess activity and resolving hallucinations and delusions. The problem: dopamine does more than cause psychosis. It also controls movement (in the basal ganglia), hormone regulation (in the pituitary), and reward/motivation. Block dopamine everywhere and you get a predictable set of movement side effects — the EPS in ADAPT.
Extrapyramidal Side Effects — ADAPT
Five movement disorders from dopamine blockade in the motor system
A — Akathisia
Inner restlessness — cannot sit still, must keep moving
Akathisia is a subjective sensation of inner restlessness and an irresistible urge to move — particularly the legs. Patients pace, shift weight constantly, cross and uncross their legs, and describe it as "crawling out of my skin." It is one of the most distressing EPS side effects.
Onset: Early — within days to weeks of starting or increasing antipsychotic dose.
Why it matters for medication adherence: Akathisia is so distressing that it is a leading cause of patients stopping their antipsychotic medications without telling their provider. A patient who was improving on medication may relapse not because the drug stopped working but because they quietly stopped taking it due to akathisia.
Management: Dose reduction if possible. Propranolol (beta blocker) — most effective pharmacological treatment for akathisia. Benzodiazepines for short-term relief. Switching to an atypical antipsychotic with lower EPS risk.
Assessment: Ask the patient: "Do you feel restless or feel like you have to move?" Observe for constant leg movement, pacing, shifting. Do not assume restlessness is psychiatric agitation — it may be drug-induced.
💊 "Akathisia looks like agitation but feels like torture." The critical mistake is treating akathisia by increasing the antipsychotic dose — because the nurse assumes the patient is more agitated from their illness. More antipsychotic makes akathisia worse. Always consider akathisia when a patient on antipsychotics is described as "agitated and cannot stay still."
D — Dystonia
Sudden, painful muscle spasms — can be life-threatening in the throat
Dystonia is sudden, sustained, involuntary muscle contractions — causing abnormal postures and movements. It is acute (sudden onset) and often dramatic.
Common dystonic reactions:
• Oculogyric crisis — eyes roll upward and become fixed, unable to look down
• Torticollis — head twisted to one side, neck muscle spasm
• Opisthotonos — back arches severely backward
• Laryngeal/pharyngeal dystonia — throat and airway muscles spasm — EMERGENCY, can cause airway obstruction
Onset: Very early — within hours to days of starting a new antipsychotic or after a dose increase. More common in young males.
Treatment: Diphenhydramine (Benadryl) 25–50mg IV/IM — works within minutes. Or benztropine (Cogentin) IM. For laryngeal dystonia — this is an airway emergency, call for help immediately while giving diphenhydramine IV.
Prevention: Anticholinergic medications (benztropine) are sometimes given prophylactically with high-potency first-generation antipsychotics to prevent dystonia.
💊 "Benadryl reverses dystonia within minutes." A patient on haloperidol develops oculogyric crisis — eyes fixed upward, cannot move them down. This is an acute dystonic reaction. Diphenhydramine 50mg IV or IM: eyes return to normal position within 5–10 minutes. Document the reaction and notify provider — antipsychotic may need to be changed or prophylactic benztropine added.
A — Akinesia (Parkinsonism)
Drug-induced Parkinson symptoms — shuffling, tremor, mask-like face
Antipsychotic-induced parkinsonism looks exactly like Parkinson disease — because both involve dopamine deficiency in the motor pathways of the basal ganglia. Antipsychotics block dopamine receptors; Parkinson disease kills the dopamine-producing neurons. The result is the same.
Signs of drug-induced parkinsonism:
• Bradykinesia — slowed movement, difficulty initiating movement
• Rigidity — "cogwheel" rigidity on passive limb movement
• Resting tremor — "pill-rolling" tremor of the hands at rest
• Mask-like face — reduced facial expression
• Shuffling gait — small steps, reduced arm swing
• Postural instability — falls risk
Onset: Subacute — develops weeks to months after starting the antipsychotic.
Management: Dose reduction, switching to lower-EPS-risk atypical antipsychotic, or adding an anticholinergic (benztropine). Levodopa is NOT given — it would worsen the psychosis by increasing dopamine.
Falls risk: Drug-induced parkinsonism significantly increases fall risk — gait instability, postural hypotension from the antipsychotic, and sedation combine dangerously.
💊 "Drug-induced Parkinsonism is reversible." True Parkinson disease is progressive and irreversible. Drug-induced parkinsonism resolves when the offending drug is reduced or stopped. This distinction is important for patients who may fear they have developed Parkinson disease after starting an antipsychotic.
P — Pseudoparkinsonism
Overlaps with Akinesia — the full Parkinson-like picture
Pseudoparkinsonism is sometimes listed separately from akinesia to capture the full Parkinson-like syndrome — including all four cardinal features of Parkinson: tremor, rigidity, bradykinesia, and postural instability. In practice, akinesia and pseudoparkinsonism are closely related and often used interchangeably in the EPS literature.
Key clinical point: When assessing a patient on antipsychotics for falls, shuffling gait, or tremor — always consider drug-induced parkinsonism. Do not assume the movement disorder is unrelated to the medication.
T — Tardive Dyskinesia
Late-onset, potentially irreversible involuntary movements — the most feared EPS
Tardive dyskinesia (TD) is the most serious and feared EPS complication. Unlike the other ADAPT side effects which occur early and are usually reversible, TD occurs after months to years of antipsychotic use and may be permanent even after the drug is stopped.
What it looks like: Involuntary, repetitive, purposeless movements — particularly affecting the face, mouth, and tongue:
• Tongue darting and rolling
• Lip smacking and puckering
• Facial grimacing
• Chewing movements
• Choreoathetoid movements of the limbs (writhing, dance-like movements)
Why it develops: Prolonged dopamine receptor blockade causes those receptors to upregulate (increase in number and sensitivity) — they become supersensitive. When the drug is reduced or stopped, this supersensitivity causes excess dopamine signaling in motor areas — producing the involuntary movements.
Prevention: Use the lowest effective dose for the shortest necessary time. Use atypical antipsychotics when possible (lower TD risk than typicals). Regular monitoring — AIMS (Abnormal Involuntary Movement Scale) assessment every 3–6 months.
Treatment: Valbenazine (Ingrezza) and deutetrabenazine (Austedo) — FDA-approved specifically for TD. Reduce or switch antipsychotic if possible.
💊 "AIMS assessment — the nursing responsibility for long-term antipsychotic patients." The Abnormal Involuntary Movement Scale checks for TD systematically — watching for lip movements, tongue movements, facial grimacing, and limb choreiform movements. Nurses administer AIMS at regular intervals. Early detection allows dose adjustment before TD becomes permanent.
Neuroleptic Malignant Syndrome
The life-threatening emergency from antipsychotics — not the same as serotonin syndrome
NMS — Four Cardinal Features
Fever, rigidity, altered consciousness, autonomic instability
Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal reaction to antipsychotic medications — or to abrupt dopamine agonist withdrawal. It is the most dangerous adverse effect of antipsychotics.
The four signs — "FARM":
• Fever — high, often above 38.5°C, can exceed 41°C
• Altered mental status — confusion, stupor, coma
• Rigidity — severe "lead pipe" muscle rigidity (distinguishes from serotonin syndrome, which has clonus)
• autonomic instability — tachycardia, labile BP, diaphoresis, incontinence
Labs in NMS: Markedly elevated CK (creatine kinase) — from muscle breakdown (rhabdomyolysis). Leukocytosis. Elevated liver enzymes.
Onset: Slower than serotonin syndrome — develops over 24–72 hours.
Treatment: Stop all antipsychotics immediately. Aggressive cooling. IV fluids for rhabdomyolysis protection. Dantrolene (muscle relaxant) for severe rigidity. Bromocriptine (dopamine agonist) to restore dopamine signaling. ICU care.
💊 "NMS: rigidity without clonus. Serotonin syndrome: clonus without the same rigidity." This distinction helps separate the two syndromes at the bedside. Both have fever and autonomic instability — the muscle findings are the differentiator.
Lithium
The original mood stabilizer — narrow window, serious toxicity
Lithium Monitoring and Toxicity
Therapeutic vs toxic levels — they are very close together
Lithium is used for bipolar disorder — mood stabilization, particularly preventing manic episodes. It is highly effective but requires careful monitoring because its therapeutic level is close to its toxic level.
Therapeutic lithium level: 0.6–1.2 mEq/L (some sources say 0.8–1.2 for acute mania).
Toxic: above 1.5 mEq/L. Severe toxicity above 2.0 mEq/L.
Early toxicity signs (level 1.5–2.0 mEq/L):
• Tremor — fine hand tremor (can be therapeutic at low levels, worsens with toxicity)
• GI symptoms — nausea, vomiting, diarrhea, abdominal pain
• Polyuria and polydipsia — lithium impairs ADH function (nephrogenic diabetes insipidus effect)
Severe toxicity signs (above 2.0 mEq/L):
• Ataxia — unsteady gait, coordination loss
• Seizures
• Cardiac arrhythmias
• Coma
What causes lithium levels to rise dangerously:
• Dehydration — lithium follows sodium; when sodium is low (dehydration, low-sodium diet), kidneys retain more lithium
• NSAIDs — reduce renal lithium clearance, raising levels
• ACE inhibitors and thiazide diuretics — same mechanism, raise lithium levels significantly
• Sodium restriction — see above
Patient education: Maintain consistent fluid and sodium intake. Avoid NSAIDs. Tell every provider you are on lithium before new medications are prescribed. Report early toxicity signs immediately.
💊 "Dehydration + lithium = toxicity." A patient on lithium gets a GI illness with vomiting and diarrhea for two days. They become dehydrated. Sodium and lithium handling in the kidney shifts — lithium accumulates. Their level climbs from 0.9 to 1.8 mEq/L. They develop tremor, confusion, and ataxia. This scenario is one of the most common causes of acute lithium toxicity. Educate patients to call their provider at the start of any illness causing fluid losses.
🏥 Clinical Scenario — EPS Recognition and Response
Mr. Osei, 28 years old, was started on haloperidol (Haldol) 5mg IM two hours ago for acute psychosis in the ED. You are the nurse assigned to his room.
2 hrs
First check: He is calmer but you notice his eyes are deviated upward and he cannot look straight ahead — oculogyric crisis. He is distressed: "I can't move my eyes, something is wrong with me." Acute dystonic reaction — D in ADAPT. Call for diphenhydramine 50mg IV immediately.
Treat
Diphenhydramine 50mg IV given: Eyes return to normal position within 8 minutes. Patient visibly relieved. Benztropine 1mg IM ordered to prevent recurrence. Provider notified — haloperidol changed to olanzapine (atypical antipsychotic with lower EPS risk). Incident documented.
Day 3
New admission assessment: Patient now on olanzapine. He reports "I cannot stop moving my legs." Observed pacing constantly, shifting in chair, unable to sit for more than 30 seconds. Temperature normal, no clonus. Akathisia — A in ADAPT. Propranolol 20mg ordered. Dose of olanzapine reviewed — no increase without reassessment.
Teach
Discharge education: Explained both EPS reactions — what they were, what caused them, and what to watch for. "If you ever feel like you cannot stop moving, or your eyes or muscles lock up after taking any psychiatric medication — go to the ER immediately. Tell them you are on an antipsychotic." Written information provided. Follow-up arranged with psychiatry in 1 week.
📌 NCLEX Application
Antipsychotic EPS, NMS, and lithium toxicity are high-yield NCLEX topics:
EPS identification: "A patient on haloperidol develops eyes fixed upward and neck muscles pulling the head to one side. What does the nurse do?" → Acute dystonic reaction — give diphenhydramine (Benadryl) IV/IM immediately.
Akathisia trap: "A patient on risperidone cannot stop pacing and shifting in her chair. She reports feeling like she cannot sit still. The nurse should:" → Recognize akathisia and notify provider — do NOT increase the antipsychotic dose. Propranolol or dose reduction are appropriate interventions.
TD recognition: "A patient on long-term chlorpromazine develops repetitive lip smacking and tongue movements. What does the nurse recognize?" → Tardive dyskinesia — report to provider immediately. Assess using AIMS scale.
NMS: "A patient on fluphenazine develops fever of 40.1°C, severe muscle rigidity, and markedly elevated CK. What is the nurse's priority?" → Stop antipsychotic immediately and call for emergency support. This is NMS.
Lithium toxicity: "A patient on lithium develops ataxia, confusion, and vomiting after starting ibuprofen for knee pain. What does the nurse suspect?" → Lithium toxicity — NSAIDs reduce lithium clearance, raising levels. Hold lithium, check level, notify provider.
⚠️ The Trap — Treating Akathisia with More Antipsychotic
A patient on haloperidol is pacing constantly, cannot sit still, and is demanding to leave. The nurse interprets this as worsening psychotic agitation and calls the provider to request an increased dose or a PRN antipsychotic for "agitation."
What is actually happening: The patient has akathisia — a drug-induced movement disorder from dopamine blockade. The restlessness is the side effect, not the psychiatric illness. Increasing the antipsychotic dose will worsen the akathisia, making the patient more distressed and more likely to decompensate or leave against medical advice.
How to distinguish: Ask the patient: "Do you feel an inner restlessness or need to move your legs?" Observe: is the movement continuous and purposeless (akathisia) or goal-directed and agitated (psychosis)? Check for other EPS signs. Consider timing — did restlessness start shortly after dose increase?
The correct response: Recognize akathisia → notify provider → anticipate propranolol order or dose reduction → do NOT increase antipsychotic.
✓ Quick Self-Test
Answer before checking:
1. What does ADAPT stand for?
2. A patient develops oculogyric crisis after haloperidol. What drug reverses it and how fast?
3. What distinguishes tardive dyskinesia from the other ADAPT side effects?
4. What are the early signs of lithium toxicity?
5. How does NMS differ from serotonin syndrome in its muscle findings?
Answers:
1. Akathisia · Dystonia · Akinesia (parkinsonism) · Pseudoparkinsonism · Tardive Dyskinesia.
2. Diphenhydramine (Benadryl) 50mg IV or IM — eyes return to normal position within 5–10 minutes. Benztropine is an alternative.
3. Tardive dyskinesia is late-onset (months to years of use) and potentially irreversible, even after stopping the drug. The other ADAPT effects are early-onset and reversible with dose adjustment or drug change.
4. Fine tremor, nausea, vomiting, diarrhea, polyuria (increased urination), and polydipsia (increased thirst). These occur at levels above 1.5 mEq/L. Severe toxicity (above 2.0) adds ataxia, seizures, and cardiac arrhythmias.
5. NMS has severe "lead pipe" rigidity without clonus. Serotonin syndrome has clonus and hyperreflexia with less pronounced rigidity. Both have fever and autonomic instability — the muscle findings differentiate them.