Loxapine Side Effects

Medically reviewed by Drugs.com. Last updated on Dec 1, 2024.

Applies to loxapine: oral capsule.

Other dosage forms:

• inhalation powder

Important warnings This medicine can cause some serious health issues

Oral route (capsule)

Elderly patients with dementia-related psychosis treated with atypical antipsychotic drugs are at an increased risk of death compared with placebo.

Although the causes of death in clinical trials were varied, most of the deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature.

Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality.

It is unclear from these studies to what extent the mortality findings may be attributed to the antipsychotic drug as opposed to patient characteristics.

Loxapine is not approved for the treatment of patients with dementia-related psychosis.

Serious side effects of loxapine

Along with its needed effects, loxapine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking loxapine:

More common side effects

• difficulty with speaking or swallowing
• lip smacking or puckering
• loss of balance control
• mask-like face
• puffing of the cheeks
• rapid or fine, worm-like movements of the tongue
• restlessness or desire to keep moving
• shuffling walk
• slowed movements
• stiffness of the arms and legs
• trembling and shaking of the fingers and hands
• uncontrolled chewing movements
• uncontrolled movements of the arms or legs

Less common side effects

• constipation (severe)
• difficult urination
• inability to move the eyes
• muscle spasms, especially of the neck and back
• skin rash
• twisting movements of the body

Rare side effects

• difficult or fast breathing
• fast heartbeat or irregular pulse
• fever (high)
• high or low blood pressure
• increased blinking or spasms of the eyelid
• increased sweating
• loss of bladder control
• muscle stiffness (severe)
• seizures
• sore throat and fever
• uncontrolled twisting movements of the neck, trunk, arms, or legs
• unusual bleeding or bruising
• unusual facial expressions or body positions
• unusual tiredness or weakness
• unusually pale skin
• yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking loxapine:

Symptoms of overdose

• dizziness, faintness, or lightheadedness when suddenly getting up from a lying or sitting position
• drowsiness (severe)
• irregular, fast or slow, or shallow breathing
• loss of consciousness
• muscle trembling, jerking, stiffness, or uncontrolled movements (severe)
• pale or blue lips, fingernails, or skin
• troubled breathing (severe)
• unusual tiredness or weakness (severe)

Other side effects of loxapine

Some side effects of loxapine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• blurred vision
• confusion
• dizziness, lightheadedness, or fainting
• drowsiness
• dryness of the mouth

Less common side effects

• constipation (mild)
• decreased sexual ability
• enlargement of the breasts (males and females)
• headache
• increased sensitivity of the skin to sunlight
• missing menstrual periods
• nausea or vomiting
• trouble with sleeping
• unusual secretion of milk
• weight gain

For healthcare professionals

Applies to loxapine: inhalation powder, intramuscular solution, oral capsule, oral concentrate.

General adverse events

The most common adverse reactions reported with use of the inhaler were dysgeusia, sedation and throat irritation. Drowsiness, extrapyramidal reactions and akathisia have been reported frequently, especially during the first few days of oral therapy.^[Ref]

Gastrointestinal

• Very common (10% or more): Dysgeusia (up to 14%)
• Common (1% to 10%): Dry mouth, throat irritation
• Frequency not reported: Constipation, excessive salivation, paralytic ileus, nausea, tongue protrusion, vomiting^[Ref]

Dysgeusia and throat irritation occurred with inhaled formulations.^[Ref]

Nervous system

• Very common (10% or more): Sedation/somnolence (up to 12%)
• Common (1% to 10%): Dizziness
• Uncommon (0.1% to 1%): Akathisia/restlessness, dystonia, dyskinesia, neck dystonia, tremor
• Frequency not reported: Akinesia, drowsiness, extrapyramidal symptoms, faintness, headache, involuntary muscle contractions, lightheadedness, masked facies, numbness, paresthesia, neuroleptic malignant syndrome, parkinsonian-like symptoms, seizures, shuffling gait, slurred speech, staggering gait, tardive dyskinesia^[Ref]

Sedation occurred in up to 12% of patients who used inhaled formulations.

Drowsiness occurred in patients who used oral formulations.

Drowsiness has been frequently reported at the beginning of therapy or when the dosage is increased. It is generally mild and usually subsides with continued therapy. The incidence of sedation has been reported as less than certain aliphatic phenothiazines, and more than the piperazine phenothiazines.^[Ref]

Other

• Common (1% to 10%): Fatigue, weakness
• Frequency not reported: Hyperpyrexia^[Ref]

Cardiovascular

• Uncommon (0.1% to 1%): Hypotension
• Frequency not reported: Tachycardia, hypertension, orthostatic hypotension, syncope, ECG changes, flushed facies^[Ref]

A few cases of ECG changes similar to those seen with phenothiazines have been reported. It is not known if these were related to loxapine administration.^[Ref]

Psychiatric

• Uncommon (0.1% to 1%): Restlessness
• Frequency not reported: Agitation, confusional state, insomnia, tension^[Ref]

Ocular

• Uncommon (0.1% to 1%): Oculogyration
• Frequency not reported: Blurred vision, dry eyes, ptosis^[Ref]

Respiratory

• Uncommon (0.1% to 1%): Bronchospasm/shortness of breath
• Frequency not reported: Dyspnea, nasal congestion^[Ref]

Bronchospasm occurred with inhaled formulations.

Use of the inhaler was shown to cause bronchospasm in clinical pulmonary safety trials as measured by FEV1 and respiratory signs and symptoms. Additionally, patients with asthma or other pulmonary diseases were shown to be at higher risk and the effect of FEV1 was greater following the second dose (administered 10 hours later).^[Ref]

Endocrine

• Rare (less than 0.1%): Galactorrhea, amenorrhea, gynecomastia, menstrual irregularity^[Ref]

Hematologic

• Rare (less than 0.1%): Leukopenia, neutropenia, agranulocytosis^[Ref]

Hepatic

• Rare (less than 0.1%): Jaundice and/or hepatitis
• Frequency not reported: Hepatocellular injury^[Ref]

Hepatocellular injury described as AST/ALT elevation has been reported in association with loxapine administration; rarely, jaundice and/or hepatitis has been reported as possibly related to treatment.^[Ref]

Dermatologic

• Frequency not reported: Dermatitis, facial edema, pruritus, rash, alopecia, seborrhea^[Ref]

Metabolic

• Frequency not reported: Weight gain, weight loss, polydipsia^[Ref]

Musculoskeletal

• Frequency not reported: Muscle twitching, rigidity^[Ref]

Hypersensitivity

• Frequency not reported: Serious skin reactions^[Ref]

Genitourinary

• Frequency not reported: Urinary retention^[Ref]

Frequently asked questions

• What drugs cause tardive dyskinesia?

Further information

Loxapine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer