How does this medication work? What will it do for me?

Loxapine belongs to the class of medications called antipsychotics. It is used to treat the symptoms of schizophrenia. This medication is believed to work by changing the way that certain nerve signals work in the brain.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

Each mL contains loxapine base (as hydrochloride) 50 mg. Nonmedicinal ingredients: hydrochloric acid and/or sodium hydroxide to adjust pH to approximately 6.0, polysorbate 80, propylene glycol, and water for injection.

How should I use this medication?

The usual recommended starting dose of loxapine is 10 mg twice daily. Your doctor will increase the dose over time until the best results occur with the least amount of side effects. The first doses of the medication may be given by an injection into the muscle. Once the best dose has been reached, the medication is usually taken in tablet or liquid form by mouth. The maximum daily dose should not be more than 250 mg.

This medication may be taken with food or with a full 250 mL (8 ounce) glass of milk or water to prevent stomach irritation. If you are taking the oral concentrated liquid, it should be mixed with orange juice or grapefruit juice and then taken as soon as possible.

Use an oral syringe to measure each dose of the liquid, as this gives a more accurate measurement than household teaspoons.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

If you are receiving the intramuscular injection form of this medication and miss an appointment to receive loxapine, contact your doctor as soon as possible to reschedule your appointment.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Loxapine should not be taken by anyone who:

  • is allergic to loxapine or to any of the ingredients of the medication
  • is experiencing circulatory collapse
  • is in a coma
  • is in a severe drug-induced depressed state from drugs such as alcohol, barbiturates, or narcotics

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • changes to menstrual periods
  • changed interest in sexual activity
  • confusion
  • constipation
  • dizziness, lightheadedness, or fainting
  • drowsiness
  • dry mouth
  • dry, itchy skin
  • enlargement of breasts (men and women)
  • headache
  • increased sensitivity of skin to sun
  • nasal congestion
  • nausea
  • increased sweating
  • trouble sleeping
  • unusual secretion of milk
  • weight changes
  • vomiting

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • blurred vision
  • difficulty controlling urination
  • difficult urination
  • difficulty speaking or swallowing
  • difficulty moving (e.g., shuffling walk, slowed movements, inability to move eyes, eye rolling, drooling, mask-like face)
  • decreased sweating
  • dizziness or fainting when rising from a sitting or lying position
  • fast or irregular heartbeat
  • increased blinking or spasms of eyelid
  • loss of balance control
  • muscle stiffness
  • restlessness or desire to keep moving
  • severe constipation
  • signs of a blood clot in the arm or leg (tenderness, pain, swelling, warmth, or redness in the arm or leg) or lungs (difficulty breathing, sharp chest pain that is worse when breathing in, coughing, coughing up blood, sweating, or passing out)
  • signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood,  bleeding gums, cuts that don’t stop bleeding)
  • signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
  • signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
  • signs of  liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
  • symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)
  • symptoms of severely increased blood pressure (e.g., chest pain, blurred vision, dizziness, excessive tiredness, headache, stronger or faster heart beat)
  • uncontrolled movements (e.g., chewing movements, twisting movements of the neck, trunk, arms, or legs, puffing up cheeks, rapid or fine, worm-like movements of tongue, lip smacking or puckering)

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • convulsions (seizures)
  • painful erection or prolonged erection that lasts more than 4 hours
  • signs of an allergic reaction (shortness of breath or difficulty breathing; hives; swelling of the eyes, mouth, lips, or throat)
  • signs of neuroleptic malignant syndrome (e.g., confusion, reduced consciousness, high fever, or muscle stiffness)
  • signs of stroke (e.g., sudden or severe headache; sudden loss of coordination; vision changes; sudden slurring of speech; or unexplained weakness, numbness, or pain in arm or leg)
  • signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood clots: This medication may increase the chance of blood clot formation, causing reduction of blood flow to organs or the extremities.

If you have a history of clotting you may be at increased risk of experiencing blood clot-related problems such as heart attack, stroke, or clots in the deep veins of your leg. Discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms such as sharp pain and swelling in the leg, difficulty breathing, chest pain, blurred vision, or difficulty speaking, contact your doctor immediately.

Blood counts: This medication can decrease the number of neutrophils (a type of white blood cell that helps fight infection), red blood cells (which carry oxygen), and platelets (which help your blood to clot). Your doctor will do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.

Drowsiness/reduced alertness: Loxapine may impair mental or physical abilities, especially during the first few days of treatment. Avoid activities requiring alertness (e.g., operating vehicles or machinery) until you know how this medication affects you. Alcohol and other sedating drugs can make you even less alert when used at the same time as this medication.

Glaucoma: Loxapine can cause the symptoms of glaucoma to become worse. If you have glaucoma, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart disease: Loxapine can cause increased heart rate and severely low blood pressure. If you have any heart conditions, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking this medication.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Neuroleptic malignant syndrome (NMS): Loxapine, like other antipsychotic medications, can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, or fainting, get immediate medical attention.

Seizures: Loxapine may increase the risk of seizures. If you have a history of epilepsy or medical conditions that increase the risk of seizures, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Stopping the medication: If this medication needs to be stopped, it should be done gradually, under the supervision of your doctor. Suddenly stopping loxapine can cause temporary involuntary movements, which may be of concern to some people.

Sunburn: An exaggerated sunburn reaction may occur for some people taking loxapine. Avoid exposure to excessive sunlight, including sunlamps and tanning beds, and use sunblock with minimum SPF 15. Talk to your doctor if you develop skin redness.

Tardive dyskinesia: A syndrome consisting of potentially irreversible, involuntary movements called tardive dyskinesia may develop in people treated with this medication. Although the risk of tardive dyskinesia appears to be highest among seniors, especially senior women, it is impossible to predict at the beginning of treatment who is likely to develop the syndrome. Tell your doctor if you start to experience signs of this syndrome, such as repetitive and involuntary movements of the face, arms, legs, or torso.

Urinary problems: Loxapine can cause urinary problems, such as difficulty urinating, to become worse. If you have urinary problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if loxapine passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children and adolescents. Its use is not recommended for people under 18 years of age.

Seniors: The safety of using this medication has not been established for adults 65 years of age or older. The increased risk of liver, kidney, and heart conditions increases the risk of side effects with the use of loxapine.

There may be a higher risk of strokes, heart attacks, and deaths associated with the use of loxapine by seniors with dementia. Seek medical attention immediately if you notice the signs and symptoms of a stroke (e.g., sudden weakness or numbness, speech problems, vision problems, dizziness, confusion, sudden severe headache) or a heart attack (e.g., discomfort or pain in the chest, back, neck, jaw, arms; sweating; shortness of breath; nausea; lightheadedness) or infection (e.g., pneumonia). Loxapine should not be used in seniors with dementia.

What other drugs could interact with this medication?

There may be an interaction between loxapine and any of the following:

  • aclidinium
  • alcohol
  • alfuzosin
  • amantadine
  • amiodarone
  • amphetamines (e.g., dextroamphetamine, lisdexamphetamine)
  • antiemetics (e.g., granisetron, ondansetron)
  • antihistamines (e.g., cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
  • antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
  • apomorphine
  • aripiprazole
  • atropine
  • azelastine
  • barbiturates (e.g., butalbital, pentobarbital, phenobarbital)
  • belladonna
  • benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
  • brimonidine
  • bromocriptine
  • buprenorphine
  • buspirone
  • chloral hydrate
  • chloroquine
  • cisapride
  • desvenlafaxine
  • dextromethorphan
  • disopyramide
  • dofetilide
  • domperidone
  • donepezil
  • dronedarone
  • droperidol
  • efavirenz
  • ergot alkaloids (e.g., ergotamine, dihydroergotamine)
  • fingolimod
  • flavoxate
  • flecainide
  • galantamine
  • general anesthetics (medications used to put people to sleep before surgery)
  • glycopyrrolate
  • ipratropium
  • ketotifen
  • lapatinib
  • levodopa
  • lithium
  • lopinavir
  • macrolide antibiotics (e.g., clarithromycin, erythromycin)
  • magnesium sulfate
  • methotrimeprazine
  • methylphenidate
  • metoclopramide
  • mirabegron
  • mirtazapine
  • monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, rasagiline, selegiline, tranylcypromine)
  • muscle relaxants (e.g., cyclobenzaprine, methocarbamol, orphenadrine)
  • nabilone
  • narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone)
  • neostigmine
  • nilotinib
  • olopatadine
  • oxybutynin
  • peginterferon Alfa-2b
  • perampanel
  • potassium chloride
  • pramipexole
  • procainamide
  • propafenone
  • quinidine
  • quinine
  • quinolone antibiotics (e.g., ciprofloxacin, norfloxacin, ofloxacin)
  • rivastigmine
  • romidepsin
  • ropinirole
  • scopolamine
  • seizure medications (e.g., clobazam, ethosuximide, felbamate, levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide)
  • selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, duloxetine, fluoxetine, paroxetine, sertraline)
  • St. John's wort
  • sotalol
  • tapentadol
  • tetrabenazine
  • thalidomide
  • thiazide diuretics (water pills; e.g., hydrochlorothiazide, indapamide, metolazone)
  • tolterodine
  • tiotropium
  • tramadol
  • tranylcypromine
  • trazodone
  • tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
  • "triptan" migraine medications (e.g., eletriptan, sumatriptan)
  • venlafaxine
  • voriconazole
  • zolpidem
  • zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

  • stop taking one of the medications,
  • change one of the medications to another,
  • change how you are taking one or both of the medications, or
  • leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.