Asenapine Side Effects

Medically reviewed by Drugs.com. Last updated on Mar 26, 2025.

Applies to asenapine: transdermal patch extended release.

Other dosage forms:

• sublingual tablet

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for any unwanted effects.

This medicine may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, hoarseness, dizziness or lightheadedness, trouble breathing, trouble swallowing, or any swelling of your hands, face, tongue, or throat while you are using this medicine.

Tell your doctor right away if you have sores or blisters in the mouth, or numbness or tingling of the mouth or throat after using this medicine.

Check with your doctor right away if you have any of the following symptoms while using this medicine: convulsions (seizures), difficulty with breathing, a fast heartbeat, a high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness. These could be symptoms of a serious condition called neuroleptic malignant syndrome (NMS).

This medicine may cause tardive dyskinesia (a movement disorder). Check with your doctor right away if you have any of the following symptoms while using this medicine: lip smacking or puckering, puffing of the cheeks, rapid or worm-like movements of the tongue, uncontrolled chewing movements, or uncontrolled movements of the arms and legs.

For diabetic patients: This medicine may affect your blood sugar levels. Check with your doctor right away if you have increased thirst or increased urination. If you notice a change in the results of your urine or blood sugar tests, or if you have any questions, check with your doctor.

This medicine may increase your weight. Your doctor may need to check your weight on a regular basis while you are using this medicine. Talk to your doctor about ways to prevent weight gain.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position suddenly. Getting up slowly may help. If this problem continues or gets worse, check with your doctor.

Asenapine can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. If you can, avoid people with infections. Check with your doctor right away if you think you are getting an infection, or if you have a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.

This medicine can cause changes in the heart rhythm, such as a condition called QT prolongation. It may change the way your heart beats and cause fainting or serious side effects. Contact your doctor right away if you have any symptoms of heart rhythm problems, such as fast, pounding, or irregular heartbeats.

This medicine may cause dizziness, drowsiness, trouble with thinking, or trouble with controlling body movements. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that requires you to be alert, well-coordinated, or able to think well.

This medicine might reduce how much you sweat. Your body could get too hot if you do not sweat enough. If your body gets too hot, you might feel dizzy, weak, tired, or confused. You might vomit or have an upset stomach. Do not get too hot while you are exercising. Avoid places that are very hot. Call your doctor if you are too hot and cannot cool down.

Heat can cause the asenapine in the patch to be absorbed into your body faster. This may increase the chance of serious side effects or an overdose. While you are using this medicine, do not use a heating pad, electric blanket, heat or tanning lamps, sauna, a sunlamp, or a heated water bed, and do not sunbathe, or take long baths or showers in hot water.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Common side effects of asenapine

Some side effects of asenapine 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:

Serious side effects of asenapine

Along with its needed effects, asenapine 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 asenapine:

For healthcare professionals

Applies to asenapine: sublingual tablet, transdermal film extended release.

General adverse events

The most commonly reported adverse reactions in adults included akathisia, dizziness, extra pyramidal symptoms other than akathisia, oral hypoesthesia, somnolence, and increased weight. The most commonly reported adverse reactions in pediatric patients included somnolence, dizziness, dysgeusia, oral paresthesia, nausea, increased appetite, fatigue, and increased weight.^[Ref]

Nervous system

• Very common (10% or greater): Somnolence (up to 53%), extrapyramidal symptoms (up to 25%), sedation (up to 19.2%), akathisia (up to 15%), headache (up to 11%), dizziness (up to 10.1%)
• Common (1% to 10%): Dysgeusia, dyskinesia, dystonia/acute dystonia, extrapyramidal disorder, parkinsonism, tremor
• Uncommon (0.1% to 1%): Dysarthria, restless leg syndrome, seizure, syncope
• Rare (less than 0.1%): Neuroleptic malignant syndrome
• Frequency not reported: Bradykinesia, cerebrovascular events, hyperkinesia, hypersomnia, lethargy, motor impairment, myoclonus, resting tremor, tardive dyskinesia^[Ref]

Somnolence occurred in up to 53% of patients aged 10 to 17 years given 5 mg orally 2 times a day.

Extrapyramidal symptoms occurred in 25% of patients given 10 mg, compared to 11% of patients given 5 mg.^[Ref]

Gastrointestinal

• Very common (10% or greater): Oral hypoesthesia (up to 30%), oral paresthesia (up to 11%)
• Common (1% to 10%): Abdominal pain, constipation, dry mouth, dyspepsia, glossodynia, nausea, oropharyngeal pain, salivary hypersecretion, stomach discomfort, toothache, vomiting
• Uncommon (0.1% to 1%): Dysphagia, gastroesophageal reflux disease (GERD/GORD), oromucosal lesions (ulcerations, blustering, inflammation), swollen tongue
• Postmarketing reports: Abdominal discomfort, abdominal pain lower, abdominal pain upper, oral dysesthesia, oral peeling/sloughing, oromandibular dystonia, oropharyngeal muscular dysfunction, pharyngeal edema, swallowing difficulty, swollen throat, tongue disorder, tongue protrusion^[Ref]

Oral hypoesthesia occurred in up to 30% of pediatric patients and up to 24% of adults.

Application site reactions that include oral ulcers, blisters, peeling/sloughing, and inflammation primarily in the sublingual area have led to discontinuation of therapy in many cases. Oral hypoesthesia and/or oral paraesthesia may occur directly after administration and usually resolve in 1 hour.^[Ref]

Psychiatric

• Very common (10% or greater): Insomnia (up to 16%)
• Common (1% to 10%): Agitation, anger, anxiety, bipolar disorder, bipolar I disorder, depression, depressive symptoms, irritability, mania, schizophrenia, suicidal ideation
• Frequency not reported: Cognitive impairment^[Ref]

Other

• Very common (10% or greater): Fatigue (up to 14%)
• Uncommon (0.1% to 1%): Fall
• Rare (less than 0.1%): Idiosyncratic drug reaction
• Frequency not reported: Body temperature dysregulation, neonatal drug withdrawal syndrome^[Ref]

Metabolic

• Very common (10% or greater): Weight gain of at least 7% (up to 13.1%)
• Common (1% to 10%): Dehydration, hyperinsulinemia, increased appetite, new-onset metabolic syndrome, weight increased
• Uncommon (0.1% to 1%): Hyperglycemia, hyponatremia
• Frequency not reported: Blood insulin increased, diabetes mellitus, dyslipidemia, metabolic changes^[Ref]

While all atypical antipsychotics have been associated with metabolic changes including hyperglycemia, dyslipidemia, and weight gain, the degree of metabolic change differs for each agent.

In clinical trials with this drug, changes from baseline in fasting glucose ranged from -0.6 to 3.8 mg/dL in adults and -0.45 to 1.43 mg/dL in pediatric patients treated with this drug for 3 to 6 weeks compared with -0.2 and -2.24 mg/dL in adults and pediatric patients receiving placebo, respectively. In a 52-week double-blind, comparator-controlled trial in primarily schizophrenic patients, the mean increase in fasting glucose from baseline was 2.4 mg/dL.

An increase of 7% or more in body weight occurred in 8% to 12% of adults and 4.4% to 4.8% of pediatric patients treated with this drug for 3 weeks compared with 1.1% and 1.6%, respectively in adults and pediatric patients receiving placebo. In a 52-week double-blind, comparator-controlled trial in primarily schizophrenic patients, the mean increase in weight from baseline was 0.9 kg.^[Ref]

Musculoskeletal

• Common (1% to 10%): Arthralgia, muscle rigidity, muscle strain, myalgia
• Frequency not reported: Involuntary muscle contractions, muscle spasms, muscle twitching, musculoskeletal stiffness, neck muscle spasm^[Ref]

Very common (10% or greater: Creatine kinase elevations (up to 11.1%)

Cardiovascular

• Common (1% to 10%): Edema, hypertension, orthostatic hypotension, peripheral edema, tachycardia
• Uncommon (0.1% to 1%): Bundle branch block, hypotension, QT prolongation on ECG, sinus bradycardia, sinus tachycardia, temporary bundle branch block
• Frequency not reported: Heart rate increased^[Ref]

In a dedicated QT study in patients with schizophrenia, doses of 5, 10, 15, and 20 mg twice a day were compared with placebo. QTc interval increases ranged from 2 to 5 msec. No patients had QTc increases of 60 msec or greater, nor did any patient experience a QTc of 500 msec or greater.

Orthostatic hypotension was reported in 4.1% of elderly subjects compared with 0.3% in the combined study populations.^[Ref]

Hepatic

• Common (1% to 10%): ALT increased, AST increased, angioedema, transient asymptomatic elevations in hepatic transaminases^[Ref]

Transient elevations in serum transaminases (primarily ALT) in the short-term schizophrenia and bipolar mania trials were more common in treated patients but mean changes were not clinically relevant. In short-term, placebo-controlled schizophrenia trials, the mean increase in transaminase levels for treated patients was 1.6 units/L compared to a decrease of 0.4 units/L for placebo treated patients. The proportion of patients with transaminase elevations three or more times the ULN (at the endpoint) was 0.9% for treated patients versus 1.3% for placebo treated patients. In short-term, placebo-controlled bipolar mania trials, the mean increase in transaminase levels for treated patients was 8.9 units/L compared to a decrease of 4.9 units/L in placebo treated patients. The proportion of patients with transaminase elevations three or more times the ULN (at the endpoint) was 2.5% for treated patients versus 0.6% for placebo treated patients. No cases of more severe liver injury were seen. In a 52 week, double-blind, comparator controlled trial of patients with schizophrenia and schizoaffective disorder, the mean increase from baseline of ALT was 1.7 units/L.^[Ref]

Respiratory

• Common (1% to 10%): Dyspnea, nasal congestion, nasopharyngitis
• Rare (less than 0.1%): Pulmonary embolism
• Frequency not reported: Difficulty breathing, throat tightness, upper respiratory tract infection
• Postmarketing reports: Choking, wheezing^[Ref]

Genitourinary

• Common (1% to 10%): Dysmenorrhea
• Uncommon (0.1% to 1%): Amenorrhea, enuresis, sexual dysfunction
• Rare (less than 0.1%): Galactorrhea^[Ref]

Dermatologic

• Common (1% to 10%): Rash
• Uncommon (0.1% to 1%): Photosensitivity reaction^[Ref]

Ocular

• Uncommon (0.1% to 1%): Accommodation disorder, blurred vision, diplopia
• Frequency not reported: Blepharospasm, oculogyration^[Ref]

Hematologic

• Uncommon (0.1% to 1%): Anemia
• Rare (less than 0.1%): Neutropenia, thrombocytopenia
• Frequency not reported: Agranulocytosis, leukopenia^[Ref]

Endocrine

• Uncommon (0.1% to 1%): Decreased prolactin levels
• Rare (less than 0.1%): Gynecomastia
• Frequency not reported: Hyperprolactinemia^[Ref]

Hypersensitivity

• Uncommon (0.1% to 1%): Allergic reactions
• Postmarketing reports: Anaphylactic/anaphylactoid reactions, serious hypersensitivity reactions^[Ref]

Local

• Postmarketing reports: Sublingual application site reactions^[Ref]

See also:

Further information

Asenapine 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.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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