Olanzapine (generic for Zyprexa®)

Olanzapine is the generic equivalent of Zyprexa®. Olanzapine also comes in an oral disintegrating tablet and is the generic equivalent of Zyprexa® Zydis.

By law, a generic drug must be the same as its brand name counterpart in terms of active ingredient, dosage, safety, effectiveness, strength, stability, and quality. A generic may, however, differ in its inactive ingredients (i.e. flavoring, fillers, and preservatives).

Olanzapine (Zyprexa®) does come with serious warnings. These include:

• Increased risk of death and cerebrovascular events (i.e. stroke, transient ischemic attack) in older adults with dementia-related psychosis*

• Worsening depression; increased risk of suicidal thoughts or actions in young adults

• Increased fall risk

• Infection risk due to decreased white blood cell count (WBC)

• Neuroleptic Malignant Syndrome

• Metabolic changes, including high blood sugar, increased cholesterol and triglycerides, and weight gain

• Tardive dyskinesia—a movement disorder featuring uncontrollable, strange, repetitive movements of the face and/or other body parts

• Low blood pressure (hypotension)

• High prolactin levels

• Seizures

• Decreased thyroid hormone levels (hypothyroidism)

• Prolongation of QT interval—a potentially life-threatening heart rhythm disorder that can cause fast, irregular heartbeats

• Cognitive and motor impairment

If any of the above concern you, speak with your doctor or pharmacist about your perceived risk and other treatment options that exist.

*This warning is a boxed warning. A boxed warning is the most serious type of medication warning assigned by the FDA.

Olanzapine is FDA approved for:

• Schizophrenia

• Acute treatment of manic or mixed episodes associated with bipolar I disorder

• Maintenance of bipolar I disorder

Olanzapine can be used in combination with fluoxetine for:

• Treatment of depressive episodes associated with bipolar I disorder

• Treatment-resistant depression

Olanzapine is an atypical antipsychotic. How olanzapine works remains unclear, but it’s thought to work on certain neurotransmitters (dopamine and serotonin) in the brain to improve behaviors and mood.

The most common side effects of olanzapine include:

• Constipation

• Weight gain

• Dizziness, headache

• Drowsiness

• Abnormal physical weakness or fatigue (asthenia)

• Increased appetite

• Low blood pressure when standing after sitting or lying down (postural hypotension)

• Abdominal pain

Side effects may improve over time as your body adjusts to the medicine.

This list doesn’t represent all possible side effects (or serious side effects) of olanzapine. If you’re experiencing any ongoing, bothersome side effect(s), tell your healthcare provider right away.

If you’d like to learn more, speak with your doctor or pharmacist. The Food and Drug Administration (FDA) also has a helpful medication guide for olanzapine here.

Olanzapine can interact with some medicines and supplements. It’s always recommended to give both your doctor and pharmacy an updated list of everything you’re taking, so drug interactions can be identified.

Some medicines and supplements olanzapine can interact with include:

• Certain anti-infective drugs: erythromycin, fluconazole, indinavir, ketoconazole, posaconazole, ritonavir

• St. John’s Wort

• Blood pressure medicines

• Seizure medicines: phenytoin, carbamazepine, divalproex

• Pimozide

• Alcohol

• Other antipsychotic medications: thioridazine

• Antidepressants: sertraline, citalopram, fluoxetine, fluvoxamine, nefazodone

• Drugs that act on the central nervous system (CNS): carbamazepine, lithium, valproate

• Benzodiazepines: lorazepam, diazepam

• Opioids: tramadol, morphine

This list doesn’t represent all the drugs that may not be safe to take with olanzapine. If you’re unsure whether a certain drug or supplement can be taken with olanzapine, speak with your doctor or pharmacist. The FDA also has a helpful medication guide for olanzapine here.

If you accidentally miss your dose of olanzapine, take the dose as soon as you remember. If it’s almost time for your next dose (within 2 hours), skip the missed dose and take your next dose at the usual time. Don't take 2 doses at the same time or extra doses.

Olanzapine may be taken with or without food.

During pregnancy: Research suggests that olanzapine isn’t associated with birth defects, but pregnancy complications were seen in some animal studies. Some evidence also suggests that women taking olanzapine while pregnant may be more likely to develop gestational diabetes.

While breastfeeding: Olanzapine enters breastmilk in small amounts and is unlikely to cause side effects in your baby. If you breastfeed while taking olanzapine, monitor your baby for side effects, especially sleepiness.

It’s important to treat mental health-related conditions when pregnant or nursing, as untreated depression, anxiety, or other mental illnesses can harm both you and baby. Always let your provider know if you’re pregnant or breastfeeding, so you can discuss the risks and benefits of starting or continuing olanzapine.

It’s recommended to avoid or limit the use of alcohol when taking olanzapine. Alcohol can intensify the side effects of olanzapine, including dizziness and sleepiness.