Asenapine Side Effects

Not all side effects for asenapine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to asenapine: sublingual tablet

In addition to its needed effects, some unwanted effects may be caused by asenapine. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking asenapine:

More common
  • Abnormal or decreased touch sensation
  • inability to move the eyes
  • inability to sit still
  • increase in body movements
  • increased blinking or spasms of the eyelid
  • lip smacking or puckering
  • need to keep moving
  • puffing of the cheeks
  • rapid or worm-like movements of the tongue
  • restlessness
  • shakiness in the legs, arms, hands, or feet
  • sticking out of tongue
  • trembling or shaking of the hands or feet
  • trouble with breathing, speaking, or swallowing
  • twitching, twisting, uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
  • uncontrolled chewing movements
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual facial expressions
  • weakness of the arms and legs
Less common
  • Blurred vision
  • dizziness
  • headache
  • nervousness
  • pounding in the ears
  • slow or fast heartbeat
  • Black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • changes in patterns and rhythms of speech
  • coma
  • confusion
  • convulsions
  • decreased urine output
  • fast, pounding, or irregular heartbeat or pulse
  • increased thirst
  • muscle pain or cramps
  • nausea or vomiting
  • pale skin
  • pinpoint red spots on the skin
  • shortness of breath
  • slurred speech
  • swelling of the face, ankles, or hands
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Some of the side effects that can occur with asenapine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Constipation
  • sleepiness or unusual drowsiness
  • sleeplessness
  • trouble sleeping
  • unable to sleep
  • unusually deep sleep
  • unusually long duration of sleep
Less common
  • Acid or sour stomach
  • belching
  • depression
  • difficulty with moving
  • dry mouth
  • fear or nervousness
  • heartburn
  • increased appetite
  • increased watering of the mouth
  • increased weight
  • indigestion
  • irritability
  • muscle pain or stiffness
  • pain in the arms or legs
  • pain in the joints
  • stomach discomfort, upset, or pain
  • toothache

For Healthcare Professionals

Applies to asenapine: sublingual tablet

Nervous system

Very common (10% or more): Insomnia (15 to 16%), somnolence (13 to 15%), extrapyramidal symptoms (excluding akathisia) (9 to 12%), headache (12%), dizziness (11%)
Common (1% to 10%): Akathisia/hyperkinesia (4 to 11%), fatigue (3 to 4%)
Frequency not reported: Neuroleptic malignant syndrome, dysarthria[Ref]

Symptoms of dystonia may occur in susceptible individuals during the first few days of treatment. Dystonic symptoms include: spasm of the neck muscles, sometimes progressing to tightness of the throat, swallowing difficulty, difficulty breathing, and/or protrusion of the tongue. While these symptoms can occur at low doses, they occur more frequently and with greater severity with high potency and at higher doses of first generation antipsychotic drugs. There is an elevated risk of acute dystonia in males and younger age groups.[Ref]


Common (1% to 10%): Anxiety (4%), depression (2%), irritability (1 to 2%)[Ref]


Common (1% to 10%): Oral hypoesthesia (5 to 7%), vomiting (4 to 7%), constipation (4 to 7%), dyspepsia (4%), oral hypoesthesia (4%), toothache (3%), dry mouth (1 to 3%), salivary hypersecretion (1 to 4%), stomach discomfort (1 to 3%)
Frequency not reported: Oral paraesthesia, glossodynia, swollen tongue[Ref]


Common (1% to 10%): Increased appetite (2 to 3%), weight gain (2 to 3%)[Ref]


Very common (10% or more):
Common (1% to 10%): Arthralgia (3%), pain in extremity (2%)
Frequency not reported: Dystonia (especially in young males), spasm of the neck muscles, tightness of the throat, swallowing difficulty, difficulty breathing, and/or protrusion of the tongue[Ref]


Frequency not reported: Transient elevations in serum transaminase[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 asenapine 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 asenapine treated patients versus 1.3% for placebo treated patients. In short-term, placebo-controlled bipolar mania trials, the mean increase in transaminase levels for asenapine 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 asenapine 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]


Frequency not reported: Thrombocytopenia, anemia[Ref]


Common (1% to 10%): Hypertension (2 to 3%), peripheral edema (3%)
Frequency not reported: Tachycardia, temporary bundle branch block, hypotension, bradycardia, sinus pauses[Ref]


Frequency not reported: Accommodation disorder[Ref]


Postmarketing reports: Idiosyncratic drug reaction, anaphylaxis, angioedema, hypotension, tachycardia, swollen tongue, dyspnea, wheezing and rash. (In several cases, these reactions occurred after the first dose).[Ref]


Frequency not reported: Oral hypoesthesia and/or oral paresthesia may occur directly after administration and usually resolves within 1 hour.
Postmarketing reports: Application site reactions, primarily in the sublingual area (e.g., oral ulcers, blisters, peeling/sloughing, and inflammation).


1. "Product Information. Saphris (asenapine)." Schering-Plough Corporation, Kenilworth, NJ.

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