CHPPC Module 22, Section 4.2: The Behavioral Health Pavilion
MODULE 22: THE HOSPITAL ECOSYSTEM

Section 4.2: The Behavioral Health Pavilion: Inpatient Psychiatry

Transition your expertise from managing chronic mental illness to mastering the pharmacology of acute psychiatric crises, from emergency de-escalation to building the perfect long-acting injectable regimen for a safe discharge.

SECTION 4.2

The Behavioral Health Pavilion: Inpatient Psychiatry

Where safety and stabilization are paramount.

4.2.1 The “Why”: Providing Safety and Stabilization During Acute Psychiatric Crises

The inpatient behavioral health unit is one of the most misunderstood environments in the hospital, yet it is one where the pharmacist’s expertise is profoundly impactful. The fundamental “Why” of this unit is to provide a secure, therapeutic environment for patients who are experiencing an acute psychiatric crisis that makes them an imminent danger to themselves or others. This is the critical distinction: this is not a long-term treatment center. It is a short-term crisis stabilization unit. Patients are admitted involuntarily (on a “psychiatric hold”) or voluntarily when their symptoms—such as severe depression with suicidal ideation, mania with dangerous impulsivity, or psychosis with command hallucinations—have become unmanageable and unsafe in the community.

The entire philosophy of the unit revolves around two sequential goals: first, ensure safety for the patient and the staff, and second, achieve medical stabilization of the acute symptoms. Safety is achieved through environmental controls (e.g., locked doors, ligature-proof fixtures) and, when necessary, pharmacological intervention to manage acute agitation. Once safety is established, the focus shifts to stabilization. This involves initiating or titrating psychotropic medications to reduce the burden of acute symptoms to a point where the patient is no longer a danger to themselves or others and can be safely discharged back to outpatient care. Your role as a pharmacist is to be the master of the potent medications used to achieve both of these goals, navigating a world of high-risk drugs, complex side effect profiles, and the critical transition to long-term adherence strategies.

Retail Pharmacist Analogy: From MTM Specialist to Crisis De-escalation Expert

In your community practice, you are a master Medication Therapy Management (MTM) Specialist for mental health. You work with stable patients over months and years, reviewing their regimens, counseling on the importance of adherence to their SSRI or antipsychotic, and helping them manage long-term side effects. Your goal is optimization and maintenance.

The inpatient psychiatric pharmacist is a Crisis De-escalation Expert. You encounter the very same patients, but on the worst day of their illness. The MTM plan has failed, adherence has lapsed, or an external stressor has triggered a severe decompensation. Your first job is not to think about long-term optimization. Your first job is to help the team safely and rapidly de-escalate a dangerous situation using emergency medications. Only after the immediate crisis is controlled do you put your MTM hat back on, analyzing the patient’s history, identifying the cause of the failure, and designing a new, more robust medication plan—often involving long-acting injectables—to prevent the next crisis.

4.2.2 The Pharmacist’s Role: Master of Rapid Tranquilization and LAIs

From the “B52” to Invega Trinza: mastering the full spectrum of psychiatric pharmacotherapy.

Mastery 1: The Art and Science of Rapid Tranquilization

Acute agitation is a medical emergency. A patient who is severely agitated, aggressive, and not responsive to verbal de-escalation poses a significant risk to themselves and the staff. Rapid tranquilization (RT) is the use of parenteral medication to quickly calm the patient to a point where they are no longer a danger. It is a high-stakes intervention that requires a deep understanding of pharmacology, dosing, and potential complications.

The Goal of RT: Calm, Not Asleep

This is the most critical concept. The goal of rapid tranquilization is not to render the patient unconscious or sedated to the point of unarousability. The goal is to reduce their agitation and anxiety to a state of tranquility, where they are calm, safe, and able to engage with the team. Over-sedation is a medical complication; it can lead to respiratory depression, aspiration, and masks the patient’s underlying psychiatric symptoms, making diagnosis and treatment more difficult.

The RT Toolkit: Your Arsenal for Acute Agitation

You will typically use a benzodiazepine, an antipsychotic, or a combination of the two. The choice depends on the suspected etiology of the agitation, the patient’s history, and the desired clinical effect.

Drug Class Agent(s) & Dosing Mechanism & Clinical Effect Your Clinical Pearls & Monitoring
Benzodiazepines Lorazepam (Ativan)
1-2 mg IM/IV		 GABA-A agonist. Provides rapid anxiolysis and sedation. The “workhorse” BZD for agitation. Reliable and effective, especially for agitation due to alcohol withdrawal, stimulant intoxication, or generalized anxiety. Monitor for respiratory depression, especially when combined with other CNS depressants.
Midazolam (Versed)
2.5-5 mg IM/IV		 Faster onset and shorter half-life than lorazepam. Useful in the ED for very acute, severe agitation when rapid control is needed. Less ideal on the inpatient unit due to its short duration of action requiring frequent re-dosing.
First-Generation Antipsychotics (FGAs) Haloperidol (Haldol)
2.5-10 mg IM/IV		 Dopamine (D2) antagonist. Provides a calming, “anti-psychotic” effect without as much overt sedation as BZDs. Excellent for agitation due to psychosis (e.g., schizophrenia, mania). High risk for Extrapyramidal Symptoms (EPS), especially dystonia. Prophylactic benztropine or diphenhydramine is often given. Monitor QTc.
Second-Generation Antipsychotics (SGAs) Olanzapine (Zyprexa)
5-10 mg IM		 Serotonin-Dopamine antagonist. Effective for psychosis and mania-related agitation. Very effective but causes significant sedation and metabolic side effects long-term. CRITICAL WARNING: Do not administer IM olanzapine and IM lorazepam within 1 hour of each other due to risk of profound over-sedation and cardiorespiratory collapse.
Ziprasidone (Geodon)
10-20 mg IM		 Serotonin-Dopamine antagonist. Less sedating than olanzapine. A good option when you want to treat psychosis without knocking the patient out. CRITICAL WARNING: Associated with significant QTc prolongation. You must ensure a baseline EKG is done and the patient is on telemetry if possible.
Combination Therapy: The “B52” and Beyond

For severe agitation, a combination of an antipsychotic and a benzodiazepine is often used to achieve synergistic effects. The classic, though now less common, example is the “B52.”

Deconstructing the “B52”
  • Benadryl (Diphenhydramine) 50 mg IM
  • 5 mg of Haldol (Haloperidol) IM
  • 2 mg of Ativan (Lorazepam) IM

The “Why”: This combination provides the antipsychotic effect of haloperidol, the anxiolytic effect of lorazepam, and the anticholinergic/antihistaminergic effect of diphenhydramine, which both adds to the sedation and helps prevent the acute dystonic reactions associated with haloperidol. While still used, many institutions now prefer a simpler combination of just haloperidol and lorazepam to reduce the anticholinergic burden.

Mastery 2: The Long-Acting Injectable (LAI) Architect

Non-adherence is the single biggest driver of rehospitalization for patients with severe mental illness like schizophrenia and bipolar disorder. Long-acting injectable (LAI) antipsychotics are the most powerful tool in our arsenal to combat this. LAIs are administered intramuscularly every 2 weeks to 3 months, providing a steady state of medication and a safety net against relapse. The inpatient stay is the golden opportunity to identify appropriate candidates and initiate this life-changing therapy. You, the pharmacist, are the architect of this process.

The LAI Toolkit: From First-Generation to Modern Marvels

You must know the initiation protocols for these drugs inside and out. They are complex, drug-specific, and a common source of medication errors.

LAI Agent Initiation Protocol & Oral Overlap Injection Site & Frequency Your Critical Pharmacist Role
Haloperidol Decanoate (FGA) Loading Dose Strategy: Calculate a loading dose based on the patient’s oral haloperidol requirement (typically 10-20x the daily oral dose) and give over the first month.
Oral Overlap: Required for the first month.		 Gluteal IM
Every 4 weeks		 You are the master of the loading dose calculation. You must also ensure the team understands the need for a full month of oral antipsychotic overlap while the LAI reaches steady state. High risk for EPS.
Fluphenazine Decanoate (FGA) Loading Dose Strategy: Typically 1.2x the daily oral fluphenazine dose.
Oral Overlap: Required for the first 1-2 weeks.		 Gluteal IM
Every 2-3 weeks		 Similar to haloperidol, your role is calculation-heavy. You must be vigilant for EPS and ensure prophylactic anticholinergics are considered.
Risperdal Consta (SGA) NO Loading Dose.
Oral Overlap: MUST continue oral risperidone (or other antipsychotic) for 3 full weeks after the first injection.		 Gluteal IM
Every 2 weeks		 Guardian of the 3-Week Overlap. This is the most common error. The microspheres take 3 weeks to start releasing drug. Discontinuing the oral antipsychotic early will lead to relapse. You must educate the team on this.
Invega Sustenna (Paliperidone) MANDATORY Loading Dose Strategy:
Day 1: 234 mg IM (deltoid)
Day 8: 156 mg IM (deltoid)
Then monthly maintenance dose.
NO Oral Overlap Required.		 Deltoid (loading), Deltoid or Gluteal (maintenance)
Every 4 weeks		 You are the enforcer of the loading dose protocol. Both initial doses must be in the deltoid muscle for rapid absorption. No oral overlap is a huge advantage. This is one of the most common LAIs used.
Invega Trinza (Paliperidone) Prerequisite: Patient must be stable on Invega Sustenna for at least 4 months. Gluteal IM
Every 3 months		 This is a discharge planning tool. You identify a patient stable on Sustenna and recommend a switch to Trinza to the outpatient team to reduce the burden of injections. You must know the dose conversion from Sustenna to Trinza.
Abilify Maintena (Aripiprazole) Loading Dose: The first injection is the maintenance dose (e.g., 400 mg IM).
Oral Overlap: MUST continue oral aripiprazole for 14 full days after the first injection.		 Deltoid or Gluteal IM
Every 4 weeks		 Guardian of the 14-Day Overlap. Similar to Risperdal Consta, ensuring the oral overlap is not discontinued prematurely is your most critical role.
Final Check: The Five Rights of LAI Initiation

Before a patient receives their first dose of an LAI, you should mentally confirm these five things:

  1. Right Patient: Is this patient a good candidate? (e.g., history of non-adherence with schizophrenia or bipolar disorder).
  2. Right Drug: Has the patient trialed and tolerated the oral formulation of this antipsychotic first? (Especially important for drugs like aripiprazole and risperidone).
  3. Right Dose: Have you verified the correct loading dose (if applicable) and maintenance dose?
  4. Right Overlap: Is there a clear plan for the required oral antipsychotic overlap period?
  5. Right Follow-up: Is there a confirmed appointment with an outpatient clinic or provider who can administer the next injection? Giving the first dose without a plan for the second is a recipe for failure.