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Olanzapine Side Effects

Medically reviewed by Drugs.com. Last updated on Jan 30, 2024.

Applies to olanzapine: oral tablet, oral tablet disintegrating.

Other dosage forms:

Important warnings This medicine can cause some serious health issues

Oral route (tablet; tablet, disintegrating)

Risk of death is increased in elderly patients with dementia-related psychosis treated with antipsychotic drugs.

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 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.

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

Serious side effects of olanzapine

Along with its needed effects, olanzapine 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 olanzapine:

More common

  • bloating or swelling of the face, arms, hands, lower legs, or feet
  • blurred vision
  • change in vision
  • change in walking and balance
  • clumsiness or unsteadiness
  • difficulty with speaking
  • difficulty with swallowing
  • drooling
  • impaired vision
  • inability to sit still
  • loss of balance control
  • mask-like face
  • muscle trembling, jerking, or stiffness
  • need to keep moving
  • rapid weight gain
  • restlessness
  • shuffling walk
  • slowed movements
  • slurred speech
  • stiffness of the arms and legs
  • tic-like (jerky) movements of the head, face, mouth, and neck
  • tingling of the hands or feet
  • trembling or shaking of the fingers, hands, feet, legs, or arms
  • twisting movements of the body
  • uncontrolled movements, especially of the face, neck, and back
  • unusual weight gain or loss

Less common

  • bladder pain
  • bloody or cloudy urine
  • bruising
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • chest pain
  • difficult or labored breathing
  • difficult, burning, or painful urination
  • dizziness
  • excessive muscle tone
  • frequent urge to urinate
  • headache
  • inability to move the eyes
  • increased blinking or spasms of the eyelid
  • itching of the vagina or genital area
  • lack of coordination
  • large, flat, blue, or purplish patches in the skin
  • loss of bladder control
  • loss of memory
  • lower back or side pain
  • muscle tension or tightness
  • nervousness
  • pain during sexual intercourse
  • pounding in the ears
  • problems with memory
  • rhythmic movement of the muscles
  • slow, fast, pounding, or irregular heartbeat or pulse
  • speaking is less clear than usual
  • sticking out the tongue
  • thick, white vaginal discharge with no odor or with a mild odor
  • tightness in the chest
  • twitching
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unusual or incomplete body or facial movements
  • weakness of the arms and legs

Other side effects of olanzapine

Some side effects of olanzapine 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

  • acid or sour stomach
  • back pain
  • belching
  • change in personality
  • difficulty having a bowel movement (stool)
  • discouragement
  • feeling sad or empty
  • fever
  • heartburn
  • increased appetite
  • increased cough
  • indigestion
  • lack of appetite
  • lack or loss of strength
  • loss of interest or pleasure
  • runny nose
  • sneezing
  • stomach discomfort, upset, or pain
  • stuffy nose
  • thirst
  • trouble sleeping
  • trouble with concentrating
  • watering of the mouth

Less common

  • blemishes on the skin
  • body aches or pain
  • chills
  • cold sweats
  • congestion
  • cough
  • dry skin
  • dryness or soreness of the throat
  • false or unusual sense of well-being
  • heavy menstrual bleeding (periods)
  • hoarseness
  • joint pain
  • lack of feeling or emotion
  • leg cramps
  • pain in the arms or legs
  • pimples
  • sweating
  • tender, swollen glands in the neck
  • uncaring feelings
  • voice change
  • vomiting

For healthcare professionals

Applies to olanzapine: intramuscular powder for injection, intramuscular powder for injection extended release, oral tablet, oral tablet disintegrating.

Nervous system

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Post-Injection delirium/sedation syndrome, a collection of signs and symptoms consistent with olanzapine overdose has been reported following injections of the extended-release IM suspension. Events occurred in less than 0.1% of injections and in approximately 2% of patients receiving injections for up to 46 months. Onset of events ranged from soon after injection to greater than 3 hours later. The majority of patients were hospitalized and some required supportive care, including intubation. Two deaths have been reported occurring 3 to 4 days after receiving the appropriate dose of the extended-release IM suspension. In these patients, very high olanzapine blood levels were reported after death. A study undertaken to determine the cause of the elevated drug levels in these 2 deaths provides inconclusive results. As reported in a 3-23-2015 drug safety communication issued by the US Food and Drug Administration, a study in animals found much of the drug level increases could have occurred after death, but the possibility that the deaths were caused by a rapid, but delayed entry of the drug in to the bloodstream could not be ruled out.

Akathisia most commonly occurred with oral doses of 15 mg/day; akathisia events included akathisia and hyperkinesia.

Dyskinetic events included buccoglossal syndrome, choreoathetosis, dyskinesia, and tardive dyskinesia.

Dystonic events included dystonia, generalized spasm, neck rigidity, oculogyric crisis, opisthotonos, and torticollis.

Parkinsonism/parkinsonism events most commonly occurred with oral doses of 15 mg/day and included akinesia, cogwheel rigidity, extrapyramidal syndrome, hypertonia, hypokinesia, masked facies, and tremor.

Sedation most commonly occurred in adolescent patients given oral doses at least 2.5 mg/day over 3 weeks; sedation included hypersomnia, lethargy, sedation, and somnolence.

Somnolence and tremor most commonly occurred with oral doses given with lithium or valproate.[Ref]

Cardiovascular

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Collective data gathered from 17 placebo-controlled clinical studies (n=5106) involving the use of atypical antipsychotic agents, including olanzapine, for the treatment of behavioral disorders in the elderly patient with dementia showed a risk of death 1.6 to 1.7 times greater in the drug treated patient than in the placebo treated patient. The average length of duration for the trials was 10 weeks with the cause of death in the majority of cases, though not all, reported as either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. Olanzapine is not approved by the FDA for use in the treatment of behavioral disorders in elderly patients with dementia.[Ref]

Metabolic

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Olanzapine appears to have a greater association than some other atypical antipsychotics for increasing glucose levels. Mean increases of up to 15 mg/dL have been reported. The differences in mean changes in serum glucose were higher in patients with evidence of glucose dysregulation at baseline. In an analysis of patients who completed 9 to 12 months of therapy, the rate on increase in mean blood glucose slowed after approximately 6 months.

Clinically significant alterations in lipids have been observed including serum triglyceride elevations greater than 500 mg/dL. In long-term studies of at least 48-weeks in adults, increased from baseline in mean fasting cholesterol, LDL, triglycerides were 5.6 mg/dL, 2.5 mg/dL, and 18.7 mg/dL, respectively. Mean increases in fasting lipid values (total cholesterol, LDL and triglycerides) were greater in patients without evidence of lipid dysregulation at baseline.

In 13 placebo-controlled monotherapy trials, olanzapine-treated patients gained an average of 2.6 kg compared to an average 0.3 kg weight loss in placebo patients; 22.5% gained at least 7% of their baseline weight, 4.2% at least 15% of their baseline (compared to 3% and 0.3% in placebo). Clinically significant weight gain was observed across all baseline BMIs. With longer term exposure (at least 24 weeks), weight gain of 7%, 15%, or 25% or more were reported in 89.4%, 55.3%, and 29.1%, respectively. Weight gain and increased appetite were reported in 40.6%, 7.1%, and 2.5% of adolescents receiving this drug in short term treatment (approximately 22 days), respectively.[Ref]

Gastrointestinal

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Abdominal pain included abdominal pain, lower abdominal pain, and upper abdominal pain.

Nausea and dry mouth have been reported to be dose related. Dry mouth was more commonly reported when given orally with lithium or valproate.[Ref]

Hepatic

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Transient, asymptomatic elevations of hepatic transaminases were commonly seen, especially early in treatment.[Ref]

Respiratory

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Rare (0.01% to 0.1%):

Endocrine

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

In clinical studies, changes in prolactin levels were found to be statistically significantly different based on dose, higher doses were associated with higher levels of prolactin. In a study of up to 12 weeks, plasma prolactin concentrations exceeded the upper limit of normal (ULN) in approximately 30% of patients who had normal baseline prolactin values. The majority of these elevations were mild, and remained below 2 x ULN.

Approximately 47% of treated adolescent patients had significantly higher prolactin levels compared to adults.[Ref]

Hematologic

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Ocular

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Other

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Asthenia most frequently occurred in oral doses of 15 mg/day.

Residual events included movement disorder, myoclonus, and twitching.[Ref]

Hypersensitivity

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Genitourinary

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Musculoskeletal

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Dermatologic

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

Psychiatric

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

For the collection of adverse reactions, the term personality disorder was used to collect data on nonaggressive objectionable behavior.

Depression most commonly occurred with oral doses given with lithium or valproate.[Ref]

Local

Immediate-release IM injection:

Extended-release IM injection:

Immunologic

Extended-release IM injection:

Renal

Oral formulations:

Immediate-release IM injection:

Extended-release IM injection:

References

1. (2001) "Product Information. Zyprexa (olanzapine)." Lilly, Eli and Company

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

4. (2015) "Product Information. ZyPREXA Relprevv (olanzapine)." Lilly, Eli and Company

5. FDA. U.S. Food and Drug Administration (2015) Zyprexa Relprevv (olanzapine pamoate): Drug Safety Communication - FDA review of study sheds light on two deaths associated with the injectable schizophrenia drug. http://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/u

Further information

Olanzapine 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.