ADASUVE (Loxapine) Inhalation Powder

What Is ADASUVE and What Is It Used For?

ADASUVE (loxapine) is an inhaled antipsychotic medication specifically designed for the acute treatment of agitation in adults with schizophrenia or bipolar I disorder. It uses a unique thermal aerosol technology to deliver loxapine directly to the lungs, achieving rapid systemic absorption and calming effects within minutes.

ADASUVE represents a significant innovation in the management of acute agitation in psychiatric emergencies. Traditional approaches to managing severe agitation typically involve intramuscular injections of antipsychotics or benzodiazepines, which can be distressing for patients and carry risks associated with needle use. ADASUVE provides a non-invasive alternative that achieves comparable speed of onset through pulmonary delivery of loxapine.

The active ingredient, loxapine, is a well-established antipsychotic belonging to the dibenzoxazepine class. It has been used in oral form since the 1970s for the treatment of schizophrenia. ADASUVE uses Staccato technology, a novel drug delivery system that heats a thin film of loxapine to produce a thermally generated aerosol. When the patient inhales through the device, the vaporized loxapine is rapidly absorbed through the large surface area of the lungs, bypassing first-pass hepatic metabolism and resulting in rapid systemic availability.

The medication is approved for use in adults aged 18 years and older who are experiencing acute agitation associated with schizophrenia or bipolar I disorder. Agitation in these conditions can manifest as excessive motor activity, heightened emotional tension, anxiety, hostility, and in some cases, aggression. Rapid de-escalation is important both for patient safety and for the safety of healthcare personnel and other patients in the clinical environment.

Regulatory Approval and Availability

ADASUVE received FDA approval in the United States in December 2012 and was approved by the European Medicines Agency (EMA) in February 2013. In the US, it is available through a restricted distribution program known as the ADASUVE REMS (Risk Evaluation and Mitigation Strategy), which requires healthcare facilities to be enrolled and to have immediate access to equipment and medications to manage bronchospasm, including a short-acting inhaled beta-agonist such as albuterol (salbutamol).

The medication is classified as a prescription-only medicine in all markets where it is approved. It is not intended for self-administration or home use. The European regulatory status requires that it be administered under the supervision of a healthcare professional in a setting where equipment for managing bronchospasm, including short-acting beta-agonists, is available.

Mechanism of Action in Detail

Loxapine exerts its antipsychotic and anti-agitation effects primarily through antagonism at multiple neurotransmitter receptors. Its receptor binding profile includes high affinity for dopamine D2 receptors, serotonin 5-HT2A receptors, norepinephrine alpha-1 adrenergic receptors, histamine H1 receptors, and muscarinic M1 receptors. This broad receptor binding profile contributes to both its therapeutic effects and its side effect profile.

The dopamine D2 receptor blockade is considered the primary mechanism responsible for the anti-agitation effect, as excessive dopaminergic activity in mesolimbic pathways is associated with psychosis and agitation. The serotonin 5-HT2A antagonism may contribute to anxiolytic effects and may reduce the risk of extrapyramidal symptoms compared to agents that act predominantly on dopamine receptors alone.

What Should You Know Before Taking ADASUVE?

ADASUVE must not be used in patients with active airways disease such as asthma or COPD. Before administration, healthcare professionals must assess pulmonary status and ensure a short-acting bronchodilator is immediately available. The medication carries a boxed warning regarding the risk of bronchospasm.

Before ADASUVE is administered, a thorough medical assessment is essential to determine the suitability of the medication for the individual patient. Because the drug is delivered by inhalation, the respiratory system is the primary concern for safety evaluation. The prescribing healthcare professional must carefully consider the patient's respiratory history, current medications, and overall medical status before deciding to use ADASUVE.

Contraindications

ADASUVE is absolutely contraindicated in the following situations:

• Active airways disease: Patients with a current diagnosis of asthma, chronic obstructive pulmonary disease (COPD), or any other active respiratory condition associated with bronchospasm must not receive ADASUVE. Even patients with a history of airways disease who are not currently symptomatic should be carefully evaluated.
• Current use of airway medications: Patients who are currently using medications to treat airways disease (such as inhaled corticosteroids, long-acting bronchodilators, or leukotriene receptor antagonists) must not be given ADASUVE, as their use suggests underlying airway hyperreactivity.
• Acute respiratory symptoms: Patients presenting with wheezing, shortness of breath, or other acute respiratory distress must not receive ADASUVE regardless of whether they have a diagnosed respiratory condition.
• Hypersensitivity: Known hypersensitivity to loxapine or amoxapine (a closely related compound) is an absolute contraindication.

Warnings and Precautions

Several important warnings and precautions apply to the use of ADASUVE:

• Monitoring after administration: Patients must be monitored for signs and symptoms of bronchospasm for at least one hour after each dose. Vital signs including respiratory rate, oxygen saturation, and lung auscultation should be assessed regularly during this observation period.
• Neuroleptic Malignant Syndrome (NMS): As with all antipsychotic medications, ADASUVE may potentially cause NMS, a rare but life-threatening condition characterized by high fever, muscle rigidity, altered consciousness, and autonomic instability. The medication should be discontinued immediately if NMS is suspected.
• Hypotension and syncope: Loxapine can cause orthostatic hypotension due to its alpha-1 adrenergic blocking properties. Patients should remain in a supervised setting and be monitored for blood pressure changes, particularly when attempting to stand after administration.
• Falls: Somnolence and hypotension associated with ADASUVE may increase the risk of falls, which can result in fractures or other injuries. This is particularly relevant in elderly patients.
• Seizures: Loxapine, like other antipsychotics, can lower the seizure threshold. ADASUVE should be used with caution in patients with a history of seizure disorders or conditions that lower the seizure threshold.
• Anticholinergic effects: Loxapine has anticholinergic properties that can cause dry mouth, urinary retention, constipation, and blurred vision. Use with caution in patients with prostatic hypertrophy, glaucoma, or paralytic ileus.
• QT prolongation: Like many antipsychotics, loxapine may prolong the QT interval. Exercise caution in patients with cardiovascular disease, electrolyte imbalances, or those taking other QT-prolonging medications.

Pregnancy and Breastfeeding

ADASUVE should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. There are limited data on the use of inhaled loxapine in pregnant women. However, based on the established safety profile of oral loxapine and the general class effects of antipsychotics, the following considerations apply:

• Third trimester exposure: Neonates exposed to antipsychotic drugs during the third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery. These may include agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding disorder.
• Breastfeeding: Loxapine and its metabolites are excreted in breast milk. The decision to continue or discontinue breastfeeding during and after ADASUVE administration should take into account the clinical benefit to the mother and the potential risk to the infant.

Use in Elderly Patients

ADASUVE has not been specifically studied in elderly patients with dementia-related psychosis. Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. ADASUVE is not approved for the treatment of patients with dementia-related psychosis. If used in elderly patients, additional caution is warranted regarding hypotension, sedation, and fall risk.

How Does ADASUVE Interact with Other Drugs?

ADASUVE can interact with CNS depressants (increasing sedation), epinephrine (risking paradoxical hypotension), anticholinergic drugs (enhancing side effects), and QT-prolonging medications (increasing cardiac arrhythmia risk). Always inform your healthcare provider about all medications you are taking.

Drug interactions are an important consideration when using ADASUVE, particularly in the context of psychiatric emergencies where patients may be receiving multiple medications. Because loxapine is metabolized primarily by the cytochrome P450 system (CYP1A2 and CYP3A4 pathways), drugs that significantly inhibit or induce these enzymes may alter loxapine plasma levels. However, the acute, single-dose nature of ADASUVE administration makes sustained pharmacokinetic interactions less clinically significant than with chronic dosing.

The most important interactions to be aware of are pharmacodynamic interactions that can enhance the effects or toxicity of loxapine or concurrently administered drugs. These are particularly relevant in the acute care setting where rapid clinical decisions must be made.

Major Interactions

Minor Interactions

What Is the Correct Dosage of ADASUVE?

The recommended dose of ADASUVE for adults is 9.1 mg administered as a single inhalation. A lower dose of 4.5 mg may be considered. A maximum of one additional dose may be given within 24 hours if needed, but the total should not exceed 2 doses (9.1 mg each) in 24 hours.

ADASUVE is administered as a single inhalation using a disposable, single-use inhaler device. The dosing is straightforward, as each device delivers one pre-measured dose. However, careful consideration must be given to patient selection, appropriate dose selection, and post-administration monitoring. The medication is intended for acute use only and is not designed for chronic or repeated dosing over extended periods.

Adults (18 years and older)

Children

ADASUVE is not approved for use in children and adolescents under 18 years of age. The safety and efficacy of inhaled loxapine have not been established in the pediatric population. Alternative approaches to managing acute agitation in pediatric psychiatric patients should be employed under specialist guidance.

Elderly

While ADASUVE can be used in elderly patients, particular caution is warranted. Elderly patients are more susceptible to orthostatic hypotension, excessive sedation, and anticholinergic effects. The lower dose of 4.5 mg should be considered as the initial dose. It is critically important to note that antipsychotic medications, including loxapine, are associated with increased mortality when used in elderly patients with dementia-related psychosis, and ADASUVE is not approved for this indication.

Missed Dose

The concept of a missed dose does not typically apply to ADASUVE, as it is administered on an as-needed basis for acute agitation episodes rather than on a scheduled dosing regimen. If the clinical team determines that the first dose was inadequately delivered (e.g., the patient did not properly inhale), the administration may be repeated with clinical judgement. Any decision to re-dose should include reassessment of the patient's respiratory status.

Overdose

Overdose with ADASUVE specifically is limited by the single-dose device design. However, loxapine overdose in general (via any route) can produce symptoms including severe CNS depression, respiratory depression, hypotension, seizures, renal failure, and coma. Management of overdose should be symptomatic and supportive, with particular attention to maintaining an adequate airway and monitoring cardiovascular function. Gastric lavage is not relevant for the inhaled formulation. There is no specific antidote for loxapine overdose. Epinephrine should be avoided due to the risk of paradoxical hypotension; norepinephrine or phenylephrine may be used if vasopressor support is required.

How Is ADASUVE Administered?

ADASUVE is administered using a single-use, breath-actuated inhaler. The healthcare professional prepares the device by pulling the tab, instructs the patient to inhale through the mouthpiece, and the green light indicates successful delivery. The entire process takes only a few seconds.

ADASUVE uses a unique Staccato delivery system that differs fundamentally from conventional inhalers. Rather than propelling a liquid or powder suspension, the device thermally vaporizes a thin film of pure loxapine, creating a condensation aerosol with consistently small particle size optimized for deep lung delivery. This technology ensures highly reproducible dosing with minimal variability between patients.

Step-by-Step Administration

1. Preparation: Remove the ADASUVE inhaler from the sealed foil pouch. The device is ready to use and does not require shaking, priming, or assembly.
2. Activation: Pull the white plastic tab on the rear of the device. When the green light turns on, the device is ready. The green light indicates that the heater is armed and ready to generate the loxapine aerosol.
3. Patient positioning: Instruct the patient to hold the device away from the mouth and breathe out fully (exhale). The patient should not exhale into the device.
4. Inhalation: The patient places the mouthpiece between the lips and inhales through the device. The breath-actuated mechanism detects airflow and automatically triggers the heating element, generating the loxapine aerosol during inhalation.
5. Completion: The green light turns off when the dose has been successfully delivered. The patient should remove the device from the mouth and hold their breath momentarily.
6. Post-administration: Monitor the patient for at least 1 hour for signs and symptoms of bronchospasm. Assess vital signs including respiratory rate, oxygen saturation, and blood pressure.

What Are the Side Effects of ADASUVE?

The most common side effects of ADASUVE include dysgeusia (taste disturbance), sedation, and throat irritation. The most serious potential side effect is bronchospasm, which is why the drug must only be used in healthcare settings with bronchodilator rescue medication available.

As with all medications, ADASUVE can cause side effects, although not all patients will experience them. The side effect profile of inhaled loxapine reflects both the pharmacological properties of the drug (dopamine and serotonin receptor blockade, anticholinergic effects) and the inhalation route of administration (airway irritation, bronchospasm). Clinical trial data involving over 1,000 patients provide a well-characterized safety profile.

In the pivotal Phase III clinical trials, ADASUVE was generally well tolerated. Most adverse events were mild to moderate in severity and resolved without specific treatment. The most clinically significant adverse event is bronchospasm, which led to the REMS requirement and the restriction to healthcare facility administration.

Bronchospasm – The Key Safety Concern

Bronchospasm is the adverse event of greatest clinical significance with ADASUVE. In clinical trials, bronchospasm (defined as FEV1 decrease of ≥20% from baseline) was observed in approximately 0.8% of patients without known active airway disease and in a significantly higher proportion of patients with asthma or COPD (up to 54% of asthma patients in one study). This finding led to the contraindication in patients with active airways disease and the requirement for healthcare facility administration with bronchodilator availability.

Symptoms of bronchospasm may include wheezing, chest tightness, shortness of breath, and cough. These symptoms typically occur within 25 minutes of administration. If bronchospasm occurs, it should be treated immediately with a short-acting inhaled beta-2 agonist such as albuterol (salbutamol). In severe cases, additional measures including supplemental oxygen, parenteral bronchodilators, and airway management may be required.

When to Seek Immediate Medical Attention

Although ADASUVE is administered in a healthcare setting where medical personnel are present, patients and caregivers should be aware of symptoms requiring immediate intervention:

• Difficulty breathing, wheezing, or chest tightness (may indicate bronchospasm)
• High fever with muscle stiffness and confusion (may indicate NMS)
• Severe dizziness or fainting, especially when standing (may indicate hypotension)
• Irregular heartbeat, palpitations, or chest pain (may indicate cardiac effects)
• Seizures or uncontrolled muscle movements

How Should You Store ADASUVE?

ADASUVE should be stored in its sealed foil pouch at room temperature (20–25°C / 68–77°F), protected from moisture and light. It should be used within 15 minutes of removing from the pouch and pulling the activation tab.

Proper storage of ADASUVE is important to maintain the integrity and efficacy of the medication. As an inhaled formulation using Staccato thermal aerosol technology, the device contains a precision-engineered heating element and a thin film of crystalline loxapine that must be maintained in optimal condition until use.

• Storage temperature: Store at 20–25°C (68–77°F). Temporary excursions are permitted between 15–30°C (59–86°F).
• Protection: Keep in the sealed foil pouch until time of use. Protect from moisture and light.
• Shelf life: Use before the expiration date printed on the pouch and carton.
• After opening: Once removed from the foil pouch and the tab is pulled, the device must be used within 15 minutes.
• Disposal: After use, the device may retain residual heat. Allow to cool before disposal. Dispose of in accordance with institutional protocols for pharmaceutical waste.
• Keep out of reach: Store in a secure location within the healthcare facility, inaccessible to unauthorized personnel and patients.

What Does ADASUVE Contain?

Each ADASUVE inhaler contains a pre-dispensed dose of loxapine (4.5 mg or 9.1 mg) as the sole active ingredient. The device contains no propellants, excipients, or carrier particles – it delivers pure loxapine aerosol generated by thermal vaporization.

ADASUVE is distinctive among inhaled medications in that it contains no excipients, propellants, or carrier substances. The drug product consists solely of a thin film of crystalline loxapine deposited onto a metal substrate within the Staccato device. When activated by inhalation, the heating element vaporizes the loxapine film, and the resulting vapor rapidly condenses into an aerosol of pure loxapine particles with a mass median aerodynamic diameter of approximately 1–5 micrometers, ideal for deep lung deposition.

Active Ingredient

• Loxapine (as free base): 4.5 mg or 9.1 mg per single-use device

Device Components

The ADASUVE inhaler consists of the following components:

• Stainless steel substrate with loxapine film coating
• Battery-powered heating element
• Breath-actuated airflow sensor
• Green LED indicator light
• Plastic housing with mouthpiece
• Pull tab for arming the device

No propellants (such as HFA) are used. No lactose, gelatin, or other common inhaler excipients are present. This makes ADASUVE suitable for patients with lactose intolerance or sensitivities to common inhaler additives, provided they do not have active airways disease.

Frequently Asked Questions about ADASUVE

References