Pharmacology Foundations: Drug Classes Used in Psychiatry — Psychiatric Technician

Objective. Students will categorize the major psychiatric drug classes—antipsychotics, mood stabilizers, antidepressants, anxiolytics, and sedative-hypnotics—by their general mechanism of action, primary indications, and common adverse effects.

Why Psychiatric Technicians Must Know Drug Classes

You will not prescribe or dispense medications, but you will observe patients around the clock, document what you see, and report changes to the nurse or prescriber. That makes pharmacology knowledge a direct patient-safety tool. When you recognize that a patient's stiff jaw and shuffling walk are likely adverse effects of an antipsychotic—not a new illness—you act faster and more accurately. This lesson organizes the five major psychiatric drug classes so you can link any medication to its purpose and its risks.

Antipsychotics

Antipsychotics are used primarily to treat psychosis—the cluster of symptoms that includes hallucinations (sensing things that are not there), delusions (fixed false beliefs), and disorganized thinking. They are also used in bipolar disorder and, at lower doses, for agitation.

Mechanism (lay terms): Most antipsychotics reduce the activity of dopamine in specific brain pathways. Some also affect serotonin receptors. Think of them as turning down an overactive signal in the brain.

Two generations: Older, first-generation agents (also called typical antipsychotics; example: haloperidol) are highly effective but carry a higher risk of movement-related side effects. Newer, second-generation agents (also called atypical antipsychotics; example: risperidone, quetiapine, olanzapine) affect both dopamine and serotonin and have a somewhat different side-effect profile.

Common adverse effects to watch for:

Extrapyramidal symptoms (EPS): A group of movement problems caused by dopamine blockade in the motor pathways. These include muscle stiffness, tremor, slow shuffling gait (drug-induced parkinsonism), and acute dystonia (sudden, painful muscle contractions—often the face, neck, or jaw).
Akathisia: An inner sense of restlessness; patients may pace, shift weight, or say they cannot sit still. This is often mistaken for anxiety or worsening psychosis.
Orthostatic hypotension: Blood pressure drops when a patient stands, causing dizziness or falls—especially dangerous in older adults.
Metabolic effects (more common with atypicals): weight gain, elevated blood sugar, and increased cholesterol.
Tardive dyskinesia: A late-onset, potentially irreversible movement disorder involving repetitive involuntary movements, often of the mouth and tongue. Report any new abnormal movements immediately.

Neuroleptic malignant syndrome (NMS) is a rare but life-threatening emergency: high fever, severe muscle rigidity, altered consciousness, and unstable vital signs. Treat as a medical emergency.

Mood Stabilizers

Mood stabilizers are used primarily for bipolar disorder to reduce the frequency and severity of manic and depressive episodes. Some are also used as adjuncts in other conditions.

Mechanism (lay terms): These medications work by stabilizing electrical activity in nerve cells. They affect ion channels or neurotransmitter release to prevent extreme swings in brain activity.

Examples: Lithium is the classic mood stabilizer. Valproate (valproic acid) and lamotrigine are anticonvulsant medications also used as mood stabilizers.

Common adverse effects:

Lithium has a narrow therapeutic index, meaning the difference between an effective dose and a toxic dose is small. Early toxicity signs include tremor, nausea, diarrhea, and confusion. Severe toxicity can cause seizures and cardiac arrhythmias. Dehydration and certain medications (such as NSAIDs) can raise lithium levels dangerously.
Valproate: nausea, sedation, weight gain, and liver function changes.
Lamotrigine: serious skin reactions, including Stevens-Johnson syndrome, are a rare but critical safety concern—report any new rash immediately.

Antidepressants

Antidepressants treat major depressive disorder, anxiety disorders, obsessive-compulsive disorder, and several other conditions. They are not sedatives or stimulants; full therapeutic effect often takes two to four weeks.

Mechanism (lay terms): Most antidepressants increase the availability of serotonin, norepinephrine, or both in the brain by blocking their reuptake into the sending nerve cell.

Major classes:

SSRIs (selective serotonin reuptake inhibitors): Example: sertraline. Most commonly prescribed first. Side effects include nausea (often temporary), sexual dysfunction, and insomnia or sedation.
SNRIs (serotonin-norepinephrine reuptake inhibitors): Example: venlafaxine. Similar to SSRIs; may also cause elevated blood pressure.
Tricyclic antidepressants (TCAs): Older class; higher risk of cardiac effects and dangerous in overdose.

Critical safety point: All antidepressants carry a boxed warning about increased risk of suicidal thinking in children, adolescents, and young adults, especially in the first weeks of treatment. Increase monitoring and document any statements about self-harm.

Serotonin syndrome is an emergency caused by excessive serotonin activity: agitation, confusion, rapid heart rate, high blood pressure, hyperthermia, and muscle twitching. It can result from combining serotonergic medications.

Anxiolytics (Anti-Anxiety Medications)

Anxiolytics reduce symptoms of anxiety disorders. The most commonly used class is the benzodiazepines (example: lorazepam, diazepam).

Mechanism (lay terms): Benzodiazepines enhance the effect of GABA, the brain's main inhibitory (calming) neurotransmitter, slowing down nerve activity.

Common adverse effects: Sedation, impaired coordination, memory problems, and paradoxical disinhibition (some patients become more agitated). Benzodiazepines carry significant risks of physical dependence and withdrawal. Abrupt discontinuation can cause seizures—never encourage a patient to stop suddenly.

Sedative-Hypnotics

Sedative-hypnotics are used to promote sleep. Benzodiazepines overlap this category; non-benzodiazepine hypnotics (example: zolpidem) are also common.

Mechanism (lay terms): Similar to benzodiazepines—they enhance GABA activity to reduce brain arousal.

Common adverse effects: Sedation that extends into daytime (hangover effect), confusion, sleepwalking, and fall risk, particularly in older adults. Dependence is a concern with long-term use.

Your Role: Observe, Document, Report

As a psychiatric technician you do not interpret lab values or adjust doses. Your role is to:

1. Know what class a medication belongs to so you know what to watch for.

2. Document patient-reported symptoms and observed behaviors accurately.

3. Report concerning signs—stiffness, unusual movements, fever, dizziness, rash, or any safety risk—to the nurse promptly.

4. Never delay reporting because a symptom seems minor; early identification prevents serious harm.

Key terms10

Extrapyramidal symptoms (EPS)A group of movement-related adverse effects caused by dopamine blockade in motor brain pathways; includes drug-induced parkinsonism, acute dystonia, and akathisia; most commonly associated with antipsychotic medications.

AkathisiaAn uncomfortable, subjective sense of inner motor restlessness causing a patient to pace, rock, or be unable to remain still; a common adverse effect of antipsychotics that can be mistaken for worsening anxiety or agitation.

Tardive dyskinesiaA late-onset, potentially irreversible movement disorder characterized by repetitive, involuntary movements (often of the mouth, tongue, or face) associated with long-term antipsychotic use.

Narrow therapeutic indexA property of certain medications (notably lithium) where the effective dose and the toxic dose are very close together, requiring careful monitoring for signs of toxicity.

Neuroleptic malignant syndrome (NMS)A rare, life-threatening reaction to antipsychotic medications characterized by high fever, severe muscle rigidity, altered consciousness, and unstable vital signs; requires immediate emergency response.

Serotonin syndromeA potentially life-threatening condition caused by excess serotonin activity in the nervous system, presenting with agitation, confusion, rapid heart rate, high blood pressure, hyperthermia, and muscle twitching; often triggered by combining serotonergic medications.

Orthostatic hypotensionA drop in blood pressure that occurs when a patient moves from lying or sitting to standing, causing dizziness or fainting; a common adverse effect of antipsychotics and some antidepressants that increases fall risk.

GABA (gamma-aminobutyric acid)The brain's primary inhibitory neurotransmitter; benzodiazepines and sedative-hypnotics work by enhancing GABA's calming effects to reduce anxiety or promote sleep.

Reuptake inhibitionThe mechanism by which most antidepressants work: blocking the process that normally pulls neurotransmitters (such as serotonin or norepinephrine) back into the sending nerve cell, thereby increasing their availability in the synapse.

Acute dystoniaA sudden, painful involuntary muscle contraction—commonly affecting the neck, jaw, or eyes—that is an extrapyramidal adverse effect of antipsychotic medications and requires prompt reporting and medical intervention.

In class: Complete a drug-class comparison chart for at least five psychiatric medication classes using instructor-provided reference sheets derived from standard pharmacology references; include one example generic drug name per class, mechanism (in lay terms), main use, and three common side effects. · Given 10 patient-report cards describing symptoms (e.g., 'I feel stiff and my jaw is tight,' 'I keep pacing and can't sit still,' 'I feel dizzy when I stand up'), identify the likely adverse-effect category (e.g., extrapyramidal symptom, akathisia, orthostatic hypotension) and the class most likely responsible. · Participate in a pharmacology jeopardy game covering drug classes, side effects, and reporting triggers; instructor uses the game to surface and correct misconceptions in real time.
Materials: Instructor-prepared drug-class reference sheets (based on standard pharmacology texts such as Katzung or equivalent nursing pharmacology reference), drug-class comparison chart worksheet, patient-report symptom cards, jeopardy board (whiteboard or projected).
Check: Drug-class comparison chart scored against answer key: 80% accuracy across all columns. Symptom-identification activity: 8 of 10 correct adverse-effect category and drug class. Pass mark: 80%.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.