Olanzapine (Intramuscular)

As an antipsychotic, Olanzapine is an effective treatment for numerous mental health conditions including schizophrenia and bipolar disorder.


Olanzapine, which is often branded as Zyprexa, is an antipsychotic medication which is most commonly used to treat schizophrenia and bipolar disorder (mania), often in conjunction with antidepressants and other drugs designed to treat mental health conditions. It is classed an atypical antipsychotic 'which are some of the newest types of schizophrenia medication on the market.

Studies suggest that Olanzapine is slightly more effective in the treatment of the negative symptoms of schizophrenia than most typical antipsychotics, and it has a lower risk of causing negative side effects such as movement disorders. However, Olanzapine has been shown to have a higher risk of causing weight gain and diabetes in comparison to other antipsychotics.

It is believed that Olanzapine functions by either blocking or antagonizing the dopamine D2 receptor. It also strongly antagonizes the 5-HT2A receptor, and this antagonism is believed to drastically reduce the propensity for Olanzapine to cause movement disorders in comparison to other schizophrenia medications.

Olanzapine was initially patented in 1971 and branded and sold as Zyprexa shortly after. As of 2008, Olanzapine was the most popular antipsychotic medicine in the United States and the UK. The drug became generic in 2011.

This medication can also be prescribed off-label to treat other conditions, at the discretion of the prescribing doctor.

Type Of Medicine

  • Antipsychotic

Conditions Treated

Side Effects

Like many other medications, Olanzapine can potentially cause some unwanted side effects along with its desired effects.

The principal side effect of Olanzapine use is weight gain, which can be profound in some cases. It is thought that this occurs because this medication is associated with derangement in blood sugar and blood lipid profiles. Some patients undergoing long-term treatment with this medicine develop type 2 diabetes, but with careful dietary conditioning this can be avoided.

The most common side effects reported by patients undergoing both short and long-term treatment with this antipsychotic medication include the following:

  • Blurred vision
  • Swelling or bloating of the arms, hands, feet and lower legs
  • Changes in vision
  • Disruption in walking and balance
  • Unsteadiness or clumsiness
  • Difficulty speaking
  • Drooling
  • Difficulty swallowing
  • An inability to keep or sit still
  • Dry mouth
  • Impaired vision
  • Loss of control
  • A mask-like face (no movement)
  • Stiffness
  • Muscle tremors
  • A need to keep moving around
  • Fast onset, rapid weight gain
  • Shuffling when walking
  • Restlessness
  • Slurred speech
  • Jerky, tic-like movements of the neck, mouth, face and head
  • Tingling of the feet and hands
  • Shaking or trembling of the fingers
  • Twisting movements
  • Uncontrolled movements, particularly of the face, back and neck
  • Unusual weight loss

As the patient continues to receive intramuscular injections of Olanzapine as prescribed, most of the previously mentioned side effects should begin to lessen. If any of these side effects persist over a prolonged period or appear to get worse, the patient should consult their doctor or healthcare provider as soon as possible. In some instances, a doctor or pharmacist may be able to recommend ways to alleviate symptoms which are causing mild discomfort via over the counter remedies, complimentary therapies or practical solutions. For example, dry mouth, a common side effect of Olanzapine use, can be treated by the patient simply increasing their water intake or sucking on sugar-free candy.

Other side effects, which are experienced less frequently (albeit often enough to warrant mentioning) include the following:

  • Memory loss
  • Pain in the bladder
  • Lower side or back pain
  • Cloudy or bloody urine
  • Bruising
  • Muscle tension or tightness
  • Crawling, itching, prickling and tingling sensations
  • Nervousness
  • Pain during sexual intercourse
  • Chest pain
  • Pounding in the ears
  • Clouded memories
  • Painful or difficult urination
  • Dizziness
  • Excessive muscle tone
  • Irregular heartbeat or pulse
  • Difficulty annunciating clearly
  • Sticking the tongue out
  • An increased, more frequent urge to urinate
  • Headaches
  • Vaginal discharge with mild odor
  • Inability to move the eyes
  • Twitching
  • Large bluish/purple patches on the skin
  • Lack of co-ordination
  • Loss of bladder control
  • Weakness in the legs and arms
  • Incomplete facial or body movements
  • Vomiting
  • Uncaring feelings
  • Sweating
  • Leg cramps
  • A lack of emotion
  • Joint pain
  • Heavy menstrual bleeding
  • Unusual sense of wellbeing
  • Dry skin
  • Coughing
  • Congestion
  • Chills
  • Cold sweats

Typically, most patients will only observe a handful of side effects while undergoing treatment with Olanzapine 'if they experience any whatsoever. The drug is designed to alleviate the symptoms of schizophrenia and mania, and most doctors concur that the benefits of treating serious mental illness far outweigh the risks of experiencing unwanted, often temporary side effects.

Because Olanzapine greatly affects co-ordination, motor responses and reaction times, patients are advised not to drive or operate heavy machinery while undergoing therapy with this medicine. This is because the risks to the patient and/or other road users are greatly increased when reaction times are compromised. For further information, patients are advised to consult their doctor or healthcare provider.

Olanzapine can also affect the psychology of the patient. Therefore, great caution must be taken when administering this medication to patients with complex mental health issues or history of suicidal thoughts and attempts. It may be more beneficial for these patients to receive Olanzapine via intramuscular injection in a clinical setting as opposed to oral tablets, as the risk of overdose is greatly reduced.


As with all medicines, it is imperative that the patient only takes Olanzapine as prescribed by a qualified physician who specializes in mental health conditions. This means that patients must refrain from taking any more of this drug than they have been advised to ' both in terms of frequency and dose size. In addition to this, patients should stop taking Olanzapine if advised to do so by their doctor ' even if they still have a supply of the medication remaining.

Olanzapine is intended for intramuscular gluteal injection and should not be injected subcutaneously or intravenously. It should be administered only by a qualified healthcare professional. Olanzapine should be injected using a 1.5 inch, 19-gauge needle. After the needle has been inserted into the gluteal muscle, aspiration must be maintained for approximately 10 seconds to ensure that no blood has been drawn into the syringe. If blood is aspirated into the syringe, it should be discarded. A fresh preparation of the drug should be prepared and administered instead. The injection should be performed at a continuous, steady pressure. The injection site should not be massaged.

Typical adult dose for schizophrenia:

The efficacy of Olanzapine via intramuscular injection has been demonstrated in a range between 150mg to 300mg, administered on a twice-monthly basis. Alternatively, it can be administered at a higher dose once a month. Dose recommendations for the injection are typically made based on a target oral dose, as follows:

  • If the target Olanzapine oral dose is 10mg per day, then the patient should receive 210mg Olanzapine intramuscularly every two weeks, or 405mg every four weeks, for the first eight weeks of treatment. After this initial eight-week period, a maintenance dose of 150mg every two weeks, or 300mg every four weeks should be administered.
  • If the target Olanzapine oral dose is 15mg per day, then the patient should receive 300mg of Olanzapine intramuscularly every two weeks, for the first eight weeks of treatment. After this initial eight-week period, a maintenance dose of 210mg every two weeks or 405mg every four weeks should be administered.
  • If the target Olanzapine oral dose is 20mg per day, then the patient should receive 300mg of Olanzapine intramuscularly every two weeks. After an eight-week period, the patient should receive the same amount (300mg) as a maintenance dose.

It should be noted that tolerability to Olanzapine should be established with oral formulations of the drug prior to the initiation of intramuscular, extended-release therapy.

Typical adult dosage for agitated state:

An immediate-release intramuscular injection is available for adults in an agitated state associated with psychosis. An initial dose of 10mg should be injected intramuscularly in this instance. Subsequent doses (starting at 2.5mg, up to a maximum of 10mg) can be given every two hours afterwards for persistent agitation. The number of concurrent doses to combat agitated state should not exceed 3 in any 24-hour period. If the patient shows signs of postural hypotension at a clinically significant level, then additional doses are not recommended.

Typical geriatric dose for agitated state:

Older patients who are in an agitated state should receive an initial dose of 5mg of immediate-release Olanzapine. Subsequent doses may be administered 2-4 hours apart if required, up to a maximum of 10mg intramuscularly at a time.

While the manufacturers of Olanzapine provide general dose instructions, it must be reiterated that these are merely guidelines which be altered by the patient's doctor. Factors discussed between the prescribing doctor and the patient will inform the dosing decision. The age, height, weight and condition of the patient will also play a role when it comes to determining the optimum dose schedule.

There are no recommended dose sizes for children. If this medication is to be used in pediatric patients, it is at the discretion of the prescribing doctor and/or healthcare provider.

Patients should not be administered with double doses, or any more of the drug than they have been prescribed. If the patient misses a dose, they should simply arrange another appointment with their doctor or healthcare provider to receive the missed injection as soon as is practical.

If the patient experiences signs of an overdose on this or any other medication, they should seek medical attention immediately by calling the emergency services on 911 or the local poison control center on 1800-222-1222.


All drugs have the potential to interact with other chemicals and medications within the human body, and these interactions can have drastic effects on how certain medicines work. In some cases, an interaction may render a medication ineffective at treating the condition it was prescribed to alleviate. In other instances, interactions can give rise to dangerous and potentially fatal side effects. Because of these risks, it is important for the patient to keep a full, detailed list of all medicines they are currently undergoing treatment with. This extends to vitamins, over the counter remedies, herbal supplements and complimentary medicines as well as prescribed drugs.

The following is a list of medications known to interact negatively with Olanzapine. Patients who are taking any of these drugs should inform their doctor prior to starting therapy with Olanzapine:

  • Zonisamide
  • Tramadol
  • Topiramate
  • Tetrabenazine
  • Tapentadol
  • Sufentanil
  • Sodium Oxybate
  • Ropivacaine/Sufentanil
  • Remifentanil
  • Propoxyphene
  • Potassium Citrate/Sodium Citrate
  • Potassium Citrate
  • Potassium Chloride/Sodium Chloride
  • Potassium Chloride
  • Potassium Bicarbonate/Potassium Citrate
  • Potassium Bicarbonate/Potassium Chloride
  • Potassium Acetate/Potassium Bicarbonate/Potassium Citrate
  • Phentermine/Topiramate
  • Pentazocine
  • Oxymorphone
  • Oxycodone
  • Naltrexone/Oxycodone
  • Naloxone/Pentazocine
  • Naloxone/Oxycodone
  • Nalbuphine
  • Morphine/Naltrexone
  • Morphine Liposomal
  • Morphine
  • Midazolam
  • Metrizamide
  • Metoclopramide
  • Methadone
  • Meperidine/Promethazine
  • Meperidine
  • Lorazepam
  • Lidocaine/Potassium Chloride
  • Levorphanol
  • Levomethadyl Acetate
  • Iopamidol
  • Iohexol
  • Ibuprofen/Oxycodone
  • Hyoscyamine/Methenamine/Methylene Blue/Phenyl Salicylate
  • Hyoscyamine/Methenamine
  • Hyoscyamine
  • Hydroxyzine
  • Hydroxypropyl Chitosan/Terbinafine Topical
  • Hydroxyprogesterone
  • Hydromorphone/Ropivacaine
  • Hydromorphone
  • Hydroflumethiazide/Reserpine
  • Hydroflumethiazide
  • Hydrocodone/Pseudoephedrine/Triprolidine
  • Hydrocodone/Pseudoephedrine
  • Hydrocodone/Potassium Guaiacolsulfonate/Pseudoephedrine
  • Hydrocodone/Potassium Guaiacolsulfonate
  • Hydrocodone/Phenylpropanolamine
  • Hydrocodone/Phenylephrine/Pyrilamine
  • Hydrocodone/Phenylephrine
  • Hydrocodone/Pheniramine/Phenylephrine/Phenylpropanolamine/Pyrilamine
  • Hydrocodone/Ibuprofen
  • Hydrocodone
  • Hydrochlorothiazide/Valsartan
  • Hydrochlorothiazide/Triamterene
  • Hydrochlorothiazide/Timolol
  • Hydrochlorothiazide/Telmisartan
  • Homatropine/Hydrocodone
  • Guaifenesin/Hydromorphone
  • Guaifenesin/Hydrocodone/Pseudoephedrine
  • Guaifenesin/Hydrocodone/Phenylephrine
  • Guaifenesin/Hydrocodone/Pheniramine/Phenylpropanolamine/Pyrilamine
  • Guaifenesin/Hydrocodone/Pheniramine/Phenylephrine/Phenylpropanolamine
  • Guaifenesin/Hydrocodone
  • Fentanyl/Ropivacaine
  • Fentanyl
  • Droperidol/Fentanyl
  • Diphenhydramine/Hydrocodone/Phenylephrine
  • Dihydrocodeine/Phenylephrine/Pyrilamine
  • Dihydrocodeine/Phenylephrine
  • Dihydrocodeine/Guaifenesin/Pseudoephedrine
  • Dihydrocodeine/Guaifenesin/Phenylephrine
  • Dihydrocodeine/Guaifenesin
  • Diazepam
  • Dezocine
  • Dexchlorpheniramine/Hydrocodone/Phenylephrine
  • Dexbrompheniramine/Hydrocodone/Phenylephrine
  • Deutetrabenazine
  • Codeine/Pyrilamine
  • Codeine/Pseudoephedrine/Triprolidine
  • Codeine/Pseudoephedrine/Pyrilamine
  • Codeine/Pseudoephedrine
  • Codeine/Promethazine
  • Codeine/Phenylephrine/Triprolidine
  • Codeine/Phenylephrine/Pyrilamine
  • Codeine/Phenylephrine/Promethazine
  • Codeine/Phenylephrine
  • Codeine/Pheniramine/Phenylephrine/Sodium Citrate
  • Codeine/Guaifenesin/Pseudoephedrine
  • Codeine/Guaifenesin/Phenylpropanolamine
  • Codeine/Guaifenesin/Phenylephrine
  • Codeine/Guaifenesin
  • Codeine/Diphenhydramine/Phenylephrine
  • Codeine/Dexchlorpheniramine/Phenylephrine
  • Codeine/Dexbrompheniramine/Pseudoephedrine
  • Codeine
  • Clozapine
  • Clorazepate
  • Clonazepam
  • Citric Acid/Potassium Citrate/Sodium Citrate
  • Citric Acid/Potassium Citrate
  • Chlorpheniramine/Hydrocodone/Pseudoephedrine
  • Chlorpheniramine/Hydrocodone/Phenylephrine
  • Chlorpheniramine/Hydrocodone
  • Chlorpheniramine/Guaifenesin/Hydrocodone/Pseudoephedrine
  • Chlorpheniramine/Dihydrocodeine/Pseudoephedrine
  • Chlorpheniramine/Dihydrocodeine/Phenylephrine/Phenylpropanolamine
  • Chlorpheniramine/Dihydrocodeine/Phenylephrine
  • Chlorpheniramine/Codeine/Pseudoephedrine
  • Chlorpheniramine/Codeine/Phenylephrine/Potassium Iodide
  • Chlorpheniramine/Codeine/Phenylephrine/Phenylpropanolamine
  • Chlorpheniramine/Codeine/Phenylephrine
  • Chlorpheniramine/Codeine
  • Chlordiazepoxide/Methscopolamine
  • Chlordiazepoxide/Clidinium
  • Chlordiazepoxide
  • Chlorcyclizine/Codeine/Pseudoephedrine
  • Chlorcyclizine/Codeine/Phenylephrine
  • Chlorcyclizine/Codeine
  • Carbinoxamine/Hydrocodone/Pseudoephedrine
  • Carbinoxamine/Hydrocodone/Phenylephrine
  • Butorphanol
  • Bupropion/Naltrexone
  • Bupropion
  • Buprenorphine/Naloxone
  • Buprenorphine
  • Bupivacaine/Sufentanil
  • Bupivacaine/Hydromorphone
  • Bupivacaine/Fentanyl
  • Brompheniramine/Hydrocodone/Pseudoephedrine
  • Brompheniramine/Hydrocodone/Phenylephrine
  • Brompheniramine/Dihydrocodeine/Pseudoephedrine
  • Brompheniramine/Dihydrocodeine/Phenylephrine
  • Brompheniramine/Codeine/Pseudoephedrine
  • Brompheniramine/Codeine/Phenylpropanolamine
  • Brompheniramine/Codeine/Phenylephrine
  • Brompheniramine/Codeine
  • Bromodiphenhydramine/Codeine
  • Bisacodyl/Polyethylene Glycol 3350/Potassium Chloride/Sodium Bicarbonate/Sodium Chloride
  • Aspirin/Pentazocine
  • Aspirin/Oxycodone
  • Aspirin/Hydrocodone
  • Aspirin/Codeine
  • Aspirin/Carisoprodol/Codeine
  • Aspirin/Caffeine/Propoxyphene
  • Aspirin/Caffeine/Dihydrocodeine
  • Aspirin/Butalbital/Caffeine/Codeine
  • Anhydrous Calcium Iodide/Codeine
  • Ammonium Chloride/Chlorpheniramine/Codeine/Phenylephrine
  • Amitriptyline/Chlordiazepoxide
  • Alfentanil
  • Acetaminophen/Tramadol
  • Acetaminophen/Propoxyphene
  • Acetaminophen/Pentazocine
  • Acetaminophen/Oxycodone
  • Acetaminophen/Hydrocodone
  • Acetaminophen/Codeine/Guaifenesin/Pseudoephedrine
  • Acetaminophen/Codeine/Guaifenesin/Phenylephrine
  • Acetaminophen/Codeine
  • Acetaminophen/Chlorpheniramine/Codeine/Phenylephrine
  • Acetaminophen/Chlorpheniramine/Codeine
  • Acetaminophen/Caffeine/Dihydrocodeine
  • Acetaminophen/Caffeine/Chlorpheniramine/Hydrocodone/Phenylephrine
  • Acetaminophen/Butalbital/Caffeine/Codeine


Olanzapine should not be used to treat psychotic conditions which are linked to dementia. In fact, Olanzapine can even increase the risk of death in geriatric patients with dementia. Use of this medicine is therefore not advised in dementia patients.

The long-term use of Olanzapine can give rise to serious movement disorders which, in some cases, are irreversible. Symptoms include uncontrollable movements of the legs, arms, tongue, eyes, face and lips. The longer the patient takes Olanzapine, the greater the risk of developing these disorders. The risk is increased in women and older patients.

To ensure that Olanzapine is safe for them, patients are advised to inform their doctor if they currently have or have ever had:

Patients should refrain from using alcohol while undergoing treatment with Olanzapine, as this can cause imbalances which prevent the drug from working effectively.

In exceptionally rare cases, a potentially fatal symptom known as neutoleptic malignant syndrome, or NMS, has been reported in association with Olanzapine. Symptoms of this syndrome include hyperprexia, an altered mental state, rigidity of the muscles and autonomic instability. Patients and their caregivers should notify a doctor immediately upon noticing one or more of these symptoms.

Some patients have experienced orthostatic hypotension as a result of taking Olanzapine, particularly during dose titration periods. In the event of experiencing OH, patients should lie down until they feel better.

Olanzapine clearance is approximately 40 per cent high in smokers than in non-smokers. Despite this, modifications to dosage based on smoking status are not usually recommended. It is however recommended that patients quit smoking for Olanzapine efficacy as well as general health purposes.

Immediate-acting Olanzapine can cause disorientation, agitation, confusion and/or problems with walking or speech.

Women who are pregnant or intending on becoming pregnant are advised to inform their doctor while using this medicine or before treatment commences. This is because taking antipsychotic medicines during the last three months of pregnancy can cause problems in newborn babies including withdrawal symptoms, feeding problems, breathing issues, tremors, stiff muscles and limpness.

Olanzapine is excreted into breast milk and could potentially harm nursing babies. Mothers should therefore refrain from breastfeeding while undergoing treatment with Olanzapine.


Because Olanzapine is administered in a clinical setting, the patient's healthcare provider bears the responsibility for the correct storage and handling of the medication. Olanzapine intramuscular vials should be kept at controlled room temperature (between 20C and 25C) before constitution. After constitution, this medicine can be kept at room temperature for up to one hour.

Olanzapine should be stored away from sources of moisture and light and must not be frozen. The patient's healthcare provider should ensure that unwanted, unused or expired Olanzapine is disposed of in a safe and hygenic manner, in accordance with state law and FDA guidelines.


Olanzapine is a hugely beneficial medication, but it can also pose a risk to patients who do not communicate properly with their doctors and healthcare providers. As a treatment designed to combat symptoms of mental health conditions such as schizophrenia and bipolar disorder, Olanzapine helps to control hallucinations, improve behavior and alleviate anxiety associated with mood disorders. However, it can also affect the way the body responds to stimuli, as well as causing weight gain issues.

By producing feelings of drowsiness and light-headedness, Olanzapine can massively impair the day-to-day functioning of the patient if the correct precautions are not adhered to. Because of this, it is important for the patient to be up-front and honest about their own medication history. There are hundreds of medications which can interact negatively with Olanzapine, making it necessary for the patient's own interests to be as forthcoming as possible with their healthcare provider.

When administered correctly, Olanzapine helps to control mood and behaviour, as well as rebalancing dopamine and serotonin to improve thinking patterns and prevent hallucinations/psychosis. This can help the patient to live a much more enjoyable life. To achieve this, patient and doctor must work together in order to ascertain the optimum dosage levels and frequency of use.