Zyprexa dosage, forms, and strengths

Zyprexa, Eli Lilly and Company’s brand name for olanzapine, is a prescription medication that works in the brain to treat the symptoms of schizophrenia. Zyprexa is among a more recently discovered group of antipsychotics classified as second-generation or atypical antipsychotics. The exact mechanism of action of Zyprexa is unknown, although it is thought to reduce or eliminate symptoms of psychosis primarily by its effects on brain chemicals, or neurotransmitters, such as dopamine and serotonin.

Zyprexa is approved by the U.S. Food and Drug Administration (FDA) for use in people aged 13 years or older for the treatment of schizophrenia, acute manic or mixed episodes of bipolar I disorder, long-term maintenance of bipolar I disorder, and, in those 18 and older, for acute agitation associated with schizophrenia and bipolar mania.

Additionally, Symbyax, a combination of olanzapine and fluoxetine, is an antidepressant that’s approved for use in adults for treatment-resistant depression (depressive episodes that do not get better after trying at least two other antidepressants). 

Zyprexa dosage depends on the form of the drug as well as the patient’s age and condition. Use this guide to compare Zyprexa doses for different age groups and mental conditions.

RELATED: Zyprexa coupons | What is Zyprexa?

Zyprexa forms and strengths

Zyprexa and generic olanzapine are currently available in the following dosage forms:

• Zyprexa (olanzapine) tablets: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg

• Zyprexa Zydis (olanzapine) orally disintegrating tablets: 5 mg, 10 mg, 15 mg, 20 mg

• Zyprexa (olanzapine) intramuscular (IM) injection: 10 mg single-dose vial

• Zyprexa RelPrevv (olanzapine pamoate monohydrate) injection kit: 210 mg vial, 300 mg vial, 405 mg vial

Generic versions of olanzapine are available in the following dosage forms:

• Tablet: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg

• Orally dissolving tablet: 5 mg, 10 mg, 15 mg, 20 mg

• IM injection: 5 mg per mL

Zyprexa dosage for adults

Oral Zyprexa (both tablets and Zydis orally disintegrating tablets) should be given once daily without regard to meals. Dosage adjustments of 5 mg, if needed, should be given at intervals of seven days or more. Zyprexa IM for acute agitation may be followed by initiation of oral therapy if clinically appropriate.

Zyprexa RelPrevv is a long-acting, extended-release IM injection that is given in a clinic setting due to the potential serious side effect of post-injection delirium sedation syndrome (PDSS). If clinically appropriate, therapy with Zyprexa RelPrevv may be followed by initiation of oral Zyprexa therapy.

Zyprexa dosage for children and adolescents

Zyprexa is approved in patients ages 13 to 17 years for the treatment of schizophrenia and acute manic or mixed episodes of bipolar disorder. The use of Zyprexa has not been studied in adolescent patients for maintenance treatment of bipolar disorder. Based on studies in adults, it is generally recommended that adolescent patients can continue taking Zyprexa after the acute response but at a low dose.

Note: Symbyax (a combination of olanzapine and fluoxetine) may be used to treat patients with acute depressive bipolar I disorder who are 10 to 17 years old.

Zyprexa dosage restrictions

The recommended daily starting dose of Zyprexa is 2.5 to 5 mg for the following: 

• Elderly patients

• Those who are debilitated 

• Patients who are prone to hypotensive responses (abnormally low blood pressure)

• People who may have a slower metabolism and therefore a slower breakdown of Zyprexa in the body (e.g., nonsmoker, female)

Zyprexa is contraindicated and should not be given to older patients with dementia-related psychosis due to concerns of an increased risk of death, primarily due to cardiovascular events or infections. Zyprexa has an FDA-mandated “boxed warning,” also called a black box warning, regarding this.

The safety and effectiveness of Zyprexa in children younger than 13 years old have not been established and its use is not recommended. Zyprexa RelPrevv has not been studied in those younger than 18 years of age and its use is not recommended.

Zyprexa use in pets

Zyprexa is not FDA-approved for use in animals. Although atypical antipsychotics, such as olanzapine, have been used off-label to treat dogs with aggressive behavior.

How to take Zyprexa

• Follow the directions on your prescription label and read all medication guides or instruction sheets.

• Your healthcare professional may occasionally change your dose; take Zyprexa exactly as directed.

• Zyprexa can be taken with or without food.

• You may need to frequently test your blood sugar levels and cholesterol and triglyceride levels.

• Because dizziness or drowsiness may occur, avoid driving or hazardous activity until you know how Zyprexa will affect you.

• Avoid drinking alcohol.

• Avoid becoming overheated or dehydrated and drink plenty of fluids, particularly in hot weather or while exercising.

• Do not stop using Zyprexa abruptly; you should discuss with your healthcare professional how to gradually taper your dose to prevent withdrawal symptoms.

How to take Zyprexa Zydis

1. Be sure that your hands are dry.

2. Open the sachet and peel back the foil on the blister; do not push the tablet through the foil.

3. As soon as you open the blister, remove the tablet and put it into your mouth.

4. The tablet will disintegrate quickly in your saliva so that you can easily swallow it with or without drinking liquid.

Zyprexa dosage FAQs

How long does it take Zyprexa to work?

Although some show a positive effect within the first week of treatment, it can take four to six weeks for Zyprexa to have its full effect, depending on what condition is being treated. It will likely take several weeks to see improvement in your symptoms to decide if Zyprexa is the right medication for you.

How long does Zyprexa stay in your system?

Zyprexa has an average half-life of 30 hours, which means that one-half of the active drug is gone from the body within about 30 hours after stopping the medication. Daily administration of Zyprexa leads to reaching the steady-state plasma concentration (the amount of drug in the blood needed to be therapeutically effective) in about one week. 

What happens if I miss a dose of Zyprexa?

If you miss a dose of Zyprexa, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time (i.e., don’t take two at the same time).

How long can you take Zyprexa?

Antipsychotic treatment with Zyprexa is generally needed lifelong for people with schizophrenia. Atypical antipsychotics, such as Zyprexa, may increase the risk of diabetes, weight gain, and high cholesterol and triglycerides when taken for longer periods of time. Because of these potential adverse effects, it is important to routinely monitor your blood glucose levels and your cholesterol and triglyceride levels.

Your healthcare professional is the best source of information regarding the duration of treatment you need based on your symptoms and illness.

How do I stop taking Zyprexa?

Zyprexa is not considered an addictive medicine nor does it have habit-forming potential, but you should not abruptly discontinue it as withdrawal symptoms may occur, including:

• Return of psychotic symptoms

• Agitation

• Anxiety

• Diarrhea

• Trouble sleeping

• Muscle pain

• Nausea

• Sweating

• Restlessness

You should seek medical advice when discontinuing treatment and be monitored for these symptoms. A gradual reduction in dosing rather than abruptly stopping is recommended whenever possible. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. The healthcare provider may continue decreasing the dose but at a more gradual rate.

Can you overdose on Zyprexa?

In clinical trials of Zyprexa, the incidence of overdosage was identified in 67 patients. In the patient taking the largest identified amount, 300 mg, the only symptoms reported were drowsiness and slurred speech. In the overdose patients who were clinically evaluated, vital signs were usually within normal limits. 

In the general population, symptoms of overdose include drowsiness, agitation, aggression, slurred speech, confusion, increased heart rate, jerky or uncontrolled muscle movements, trouble breathing, or fainting. There is no specific antidote for an overdose of Zyprexa and any overdose event should be immediately reported to a healthcare professional.

What interacts with Zyprexa?

The following are potential drug interactions that may occur when taking Zyprexa with other medications. This is not an exhaustive list and you should always talk to your healthcare professional for advice regarding drug and food interactions before taking Zyprexa.

• Alcohol, Valium (diazepam), and antihypertensive agents, including ACE inhibitors (Prinivil, Zestril), calcium channel blockers (Norvasc, Procardia), and diuretics (hydrochlorothiazide) increase the possibility of experiencing orthostatic hypotension.

• Tegretol (carbamazepine) may decrease the blood levels and effects of olanzapine.

• Luvox (fluvoxamine), Prilosec (omeprazole), and Rimactane (rifampin) may affect the amount of time Zyprexa stays active in the body and may necessitate a dosage adjustment.

• Anticholinergic drugs given with Zyprexa can increase the risk for severe gastrointestinal (GI) adverse reactions. Common anticholinergic drugs include (but are not limited to):

  • OTC drugs: Chlor-Trimeton, Tavist, Dramamine, Benadryl, Unisom, Bonine, Phenergan

  • Rx drugs: amitriptyline, doxepin, imipramine, Paxil (paroxetine), Ditropan (oxybutynin), Detrol (tolterodine), dicyclomine, hyoscyamine, Transderm Scop (scopolamine)

What happens when you mix Zyprexa and alcohol?

Patients should avoid alcohol while taking Zyprexa due to the increased risk of experiencing orthostatic hypotension (a temporary lowering of blood pressure usually related to suddenly standing from a seated or lying position). 

What are the potential side effects of Zyprexa?

The most common side effects of Zyprexa seen in controlled clinical studies include: 

• Orthostatic hypotension

• Constipation

• Weight gain

• Hyperglycemia (high blood sugar, or glucose, levels)

• Dizziness

• Personality disorder

• Akathisia (restlessness)

• Lack of energy

• Fever

• Dry mouth

• Indigestion

• Increased appetite

• Somnolence (drowsiness)

• Tremor

• Back pain

• Speech disorder

• Increased salivation

• Amnesia

• Tingling or pricking sensation in hands and feet

• Thirst

• Depression

• Impaired or dim vision

• Parkinsonism (tremor, mask-like facial expression, drooling, rigidity, or stiff gait)

• Extrapyramidal events (movement disorders such as restlessness, spastic contractions of muscles, or jerky movements of the face and body)

Rare, but serious, side effects of Zyprexa include:

• Increased risk of death in older people who are confused, have memory loss, and have lost touch with reality (dementia-related psychosis). These are contraindications for the use of Zyprexa, i.e., not approved for these patients.

• Severe hyperglycemia (high blood sugar) in patients who may or may not already have diabetes. High blood sugar may lead to a buildup of acid in the blood due to excess ketones (ketoacidosis), coma, or death.

• High fat (cholesterol and triglycerides) levels in the blood may occur, especially in teenagers. Healthcare professionals should perform blood tests to check cholesterol and triglyceride levels before prescribing Zyprexa and routinely during treatment.

• Neuroleptic malignant syndrome (NMS), a rare reaction that affects the central nervous system (CNS) and causes symptoms like a high fever and muscle stiffness.

• Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome has been reported with Zyprexa use. DRESS is a hypersensitivity reaction that can have a broad range of symptoms, including fever, rash, facial swelling, enlarged lymph nodes, and kidney or liver injury.

• Tardive dyskinesia has been associated with antipsychotic drugs, including Zyprexa. Symptoms are repetitive body movements that can not be controlled and usually affect the face and tongue.

• Difficulty with control of body temperature. Symptoms include sweating too much or not at all, dry mouth, feeling very hot or thirsty, and urinary retention.

These are not all the possible side effects of Zyprexa. For more information regarding side effects talk to your healthcare professional.

Is it safe to take Zyprexa during pregnancy or while breastfeeding?

Women who are pregnant or planning to become pregnant should discuss the risks and benefits of Zyprexa treatment with their healthcare professionals. Antipsychotic use, including Zyprexa, has caused abnormal muscle movements and withdrawal symptoms in newborns following delivery. It is not recommended that women take Zyprexa during lactation since olanzapine passes into breast milk and may adversely affect the infant.

Related resources for Zyprexa dosages:

• Zyprexa (olanzapine), National Alliance on Mental Illness

• Adult dosing, Epocrates

• Zyprexa RelPrevv, Epocrates

• Post-injection delirium/sedation syndrome in patients with schizophrenia treated with olanzapine long-acting injection, BMC Psychiatry

• Pediatric dosing, Epocrates

• Olanzapine, American College of Veterinary Pharmacists

• Zyprexa prescribing information, FDA

• Zyprexa RelPrevv prescribing information, FDA

• Zyprexa medication guide, FDA

• Drug interactions, Epocrates