Prochlorperazine is used for the treatment of the symptoms of psychotic disorders such as excessive anxiety, tension, confusion, delusions, and agitation. It works by affecting the chemical balance in the brain. It also can be used to treat or prevent nausea and vomiting caused by the use of certain medications (e.g., cancer treatments) or motion sickness.

Your doctor may have suggested this medication for conditions other than the ones 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.

For treatment of psychiatric illness, the initial recommended adult dose of prochloperazine is 10 mg four times daily. Your doctor will gradually increase this dose until your symptoms are under control. The doses vary according to the condition being treated.

For treatment of nausea and vomiting, the recommended adult dose of prochlorperazine is usually 5 mg to 10 mg, three or four times daily.

Children's doses are usually based on weight.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. Do not change the way that you are taking the medication without consulting your doctor.

It is very important that this medication be taken on a regular schedule as prescribed by the doctor. If you miss a dose of this medication, take it as soon as you remember it. If it is almost time for your next dose, skip the missed dose and carry on with your regular schedule. Do not double-up on doses.

Stemetil^® is available in injectable, liquid, tablet, and suppository forms.

Injectable: Each mL contains prochlorperazine 5 mg. Nonmedicinal ingredients: sodium chloride, sodium citrate, sodium sulfite, and water for injection.

Liquid: Each 5 mL of red liquid contains prochlorperazine 5 mg. Nonmedicinal ingredients: artificial butterscotch flavour, artificial chocolate flavour, artificial cognac flavour, poloxamer, purified water, sodium chloride, sodium citrate, strawberry dye, and sucrose. Sucrose: 4.0 g/5 mL. The liquid does not contain tartrazine.

Tablets:
5 mg: Each varnished, peach-coloured tablet contains prochlorperazine 5 mg.
10 mg: Each varnished, peach-coloured tablet contains prochlorperazine 10 mg.
Nonmedicinal ingredients: acetic anhydride, carnauba wax, cellulose, colloidal silicon dioxide, D&C Yellow No 10, dicalcium phosphate, diethyl phthalate, FD&C Yellow No 6, magnesium stearate, sodium croscarmellose, sodium oleate, titanium dioxide, and zein. This medication does not contain tartrazine.

Suppositories: Each rectal suppository contains prochlorperazine 10 mg. Nonmedicinal ingredients: hydrogenated vegetable glycerides. This medication does not contain tartrazine.

Prochlorperazine should not be used by anyone who:

• is comatose or has a reduced level of consciousness
• is taking large doses of central nervous system depressants (barbiturates, alcohol, analgesics, or antihistamines)
• has brain damage
• has bone marrow depression or other blood disorders
• is severely depressed
• has liver damage
• has severely reduced kidney function
• has a severe heart disorder
• has a medical condition known as pheochromocytoma
• is allergic or hypersensitive to prochloperazine or any of the ingredients of the medication or to any of the phenothiazine type medications
• is a child and is undergoing surgery

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. Your health professional may be able to help you deal with some of the effects.

The following side effects may go away as your body becomes used to the medication; check with your doctor if they continue or become bothersome.

More common:

• constipation (mild)
• decreased sweating
• dizziness
• drowsiness
• dryness of mouth
• nasal congestion

  Less common:

• changes in menstrual period
• decreased sexual ability
• increased sensitivity of eyes to light
• rough or "fuzzy" tongue
• secretion of milk (unusual)
• swelling or pain in breasts
• watering of mouth
• weight gain (unusual)

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

More common:

• blurred vision, changes in colour vision, or difficulty seeing at night
• fainting
• loss of balance control
• "mask"-like face
• restlessness or need to keep moving
• shuffling walk
• stiffness of arms or legs
• trembling and shaking of hands and fingers

  Less common:

• difficulty urinating
• skin rash
• sunburn (severe)

Rare:

Check with your doctor immediately if any of the following side effects occur:

More common:

• inability to move eyes
• increased blinking or spasms of eyelid
• lip smacking or puckering
• muscle spasms of face, neck, body, arms, or legs causing unusual postures or unusual expressions on face
• puffing of cheeks
• rapid or worm-like movements of tongue
• sticking-out of tongue
• tic-like or twitching movements
• trouble breathing, speaking, or swallowing
• uncontrolled chewing movements
• uncontrolled movements of arms or legs
• uncontrolled twisting movements of neck, trunk, arms, or legs

  Rare:

• irregular or slow heart rate
• recurrent fainting

Stop taking this medication and check with your doctor immediately if any of the following side effects occur:

Rare:

• confusion (severe) or coma
• difficult or fast breathing
• drooling
• fast heartbeat
• fever
• high or low (irregular) blood pressure
• increased sweating
• loss of bladder control
• muscle stiffness (severe)
• trembling or shaking
• trouble speaking or swallowing

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.

Alcohol: The effects of alcohol may be increased by the use of this medication.

Cautions: People who take prochlorperazine are cautioned against exposure to extreme heat or certain types of insecticides ("organophosphorous" insecticides).

Constipation: If constipation develops, use caution as it may become severe.

Medical conditions: Prochlorperazine should be used with great caution for people with glaucoma, epilepsy, or enlarged prostate.

Occupational hazards: The use of this medication may impair the mental and physical abilities required for the performance of potentially hazardous tasks, such as driving a car or operating machinery.

Pregnancy: The safe use of this medication during pregnancy has not been established. Therefore, it is recommended that pregnant women only take prochlorperazine when, in the judgment of their doctor, the potential benefit outweighs the possible risk. If you are or may be pregnant, talk to your doctor about the benefits and risks of this medication.

Breast-feeding: Prochloperazine passes into breast milk. Nursing mothers should discuss with their doctor whether to stop taking the medication or stop breast-feeding.

Children: Children with an illness involving fever or dehydration seem to be much more susceptible than adults to reactions involving the muscles. In these cases, prochlorperazine should be used under close supervision and at low doses.

Prochlorperazine should not be used by children under twoyears of age unless it is considered potentially lifesaving.

Seniors: Those over 55 years of age may be more likely to experience adverse effects from this medication.

Prochlorperazine may affect how the following medications work:

• disopyramide
• epinephrine
• guanethidine
• levodopa
• procainamide
• quinidine

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. In many cases, interactions are intended or are managed by close monitoring. 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 that 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.