For all patients:
Thioridazine can cause a serious type of irregular heartbeat that may cause sudden death. There are other medications that can be used to treat your condition that are less likely to cause this life-threatening side effect. Therefore, you should not take thioridazine unless you have already been treated with at least 2 other medications for your condition and these medications did not work well or caused side effects that you could not tolerate.
Tell your doctor if you have or have ever had long QT syndrome (condition that increases the risk of developing an irregular heartbeat that may cause loss of consciousness or sudden death), a slow or irregular heartbeat, high or low blood pressure, heart disease, or a low level of potassium in your blood. Also tell your doctor if you are taking or plan to take any of the following medications: amiodarone (Cordarone), cisapride (Propulsid) (not available in the US), disopyramide (Norpace), dofetilide (Tikosyn), erythromycin (E.E.S., E-Mycin, Erythrocin), fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), moxifloxacin (Avelox), paroxetine (Paxil, Pexeva), pimozide (Orap), pindolol (Visken), procainamide, propranolol (Inderal), quinidine, sotalol (Betapace, Betapace AF), and sparfloxacin (Zagam) (not available in the US). Your doctor will probably tell you not to take thioridazine if you are taking any of these medications or if you have any of these conditions.
In addition to the medications listed above, there are other medications that may increase the risk that thioridazine will cause you to develop a serious irregular heartbeat. Before you begin to take any new medication, tell the doctor who is prescribing the medication that you are taking thioridazine.
If you experience any of the following symptoms, call your doctor immediately: fast, irregular, or pounding heartbeat; dizziness; lightheadedness; or fainting.
Keep all appointments with your doctor and the laboratory. Your doctor may order certain laboratory tests and electrocardiograms (tests to measure the electrical activity of the heart) before and during your treatment with thioridazine, especially when your dose is changed.
Talk to your doctor about the risks of taking thioridazine.
For older adults:
Studies have shown that older adults with dementia (a brain disorder that affects the ability to remember, think clearly, communicate, and perform daily activities and that may cause changes in mood and personality) who take antipsychotics (medications for mental illness) such as thioridazine have an increased chance of death during treatment.
Thioridazine is not approved by the Food and Drug Administration (FDA) for the treatment of behavior problems in older adults with dementia. Talk to the doctor who prescribed this medication if you, a family member, or someone you care for has dementia and is taking thioridazine. For more information, visit the FDA website: Web Site
Thioridazine is used to treat the symptoms of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions) in people who have already been treated with at least 2 other medications and have not been helped or who have experienced severe side effects. Thioridazine is in a group of medications called conventional antipsychotics. It works by decreasing abnormal excitement in the brain.
Thioridazine comes as a tablet to take by mouth. It is usually taken two to four times a day. Take thioridazine at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take thioridazine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor will probably start you on a low dose of thioridazine and gradually increase your dose until your symptoms are controlled. Once your symptoms have been controlled for some time, your doctor may decrease your dose. Be sure to tell your doctor how you are feeling during your treatment with thioridazine.
Thioridazine may help to control your symptoms but will not cure your condition. Continue to take thioridazine even if you feel well. Do not stop taking thioridazine without talking to your doctor.
This medication should not be prescribed for other uses; ask your doctor or pharmacist for more information.
Before taking thioridazine,
- tell your doctor and pharmacist if you are allergic to thioridazine, other phenothiazines such as chlorpromazine, fluphenazine, perphenazine, prochlorperazine (Compro), promethazine (Phenergan), or trifluoperazine; or any other medications.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements and herbal products you are taking or plan to take. Be sure to mention the medications listed in the IMPORTANT WARNING section or any of the following: antidepressants; antihistamines; atropine (in Motofen, in Lomotil, in Lonox); barbiturates such as pentobarbital (Nembutal), phenobarbital (Luminal), and secobarbital (Seconal); epinephrine (Epipen); ipratropium (Atrovent); medications for anxiety or mental illness, irritable bowel disease, motion sickness, Parkinson's disease, seizures, ulcers, or urinary problems; narcotic medications for pain; sedatives; sleeping pills; and tranquilizers. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you are thinking about killing yourself or planning or trying to do so and if you have or have ever had any of the conditions listed in the IMPORTANT WARNING section or either of the following: seizures or breast cancer. Also tell your doctor if you have ever had to stop taking a medication for mental illness due to severe side effects or if you plan to work with organophosphorus insecticides (a type of chemical used to kill insects).
- tell your doctor if you are pregnant, especially if you are in the last few months of your pregnancy, or if you plan to become pregnant or are breast-feeding. If you become pregnant while taking thioridazine, call your doctor. Thioridazine may cause problems in newborns following delivery if it is taken during the last months of pregnancy.
- talk to your doctor about the risks and benefits of taking thioridazine if you are 65 years of age or older. Older adults should not usually take thioridazine because it is not as safe as other medications that can be used to treat the same condition.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking thioridazine.
- you should know that this medication may make you drowsy and may affect your thinking and movements. Tell your doctor if you plan to drive a car or operate machinery. Your doctor will tell you if these activities are safe for you and may increase the dose of your medication very gradually so that your body can adjust to these side effects.
- ask your doctor about the safe use of alcohol while you are taking thioridazine. Alcohol can make the side effects of thioridazine worse.
Unless your doctor tells you otherwise, continue your usual diet.
Take the missed dose as soon as you remember it. However, if it is almost time for your next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Thioridazine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- blurred vision
- dry mouth
- changes in appetite
- weight gain
- stuffed nose
- pale skin
- darkening of the skin or eyes
- swelling of the arms, hands, feet, ankles, or lower legs
- blank facial expression
- shuffling walk
- unusual, slowed, or uncontrollable movements of any part of the body
- unusual dreams
- breast milk production
- breast enlargement
- missed menstrual periods
- decreased sexual ability in men
- difficulty urinating
Some side effects may be serious. If you experience any of the following symptoms or the ones listed in the IMPORTANT WARNING section, call your doctor immediately:
- muscle stiffness
- neck cramps
- tightness in the throat
- difficulty breathing or swallowing
- tongue that sticks out of the mouth
- fine, worm-like tongue movements
- uncontrollable, rhythmic face, mouth, or jaw movements
- vision loss, especially at night
- seeing everything with a brown tint
- yellowing of the skin and eyes
- erection that lasts for hours
Thioridazine may cause other side effects. Call your doctor if you have any unusual problems while you are taking thioridazine.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at Web Site] or by phone [1-800-332-1088].
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include:
- slow, fast, or irregular heartbeat
- slowed or unusual movements
- high or low body temperature
- coma (loss of consciousness for a period of time)
- widened or narrowed pupils (black circles in the middle of the eyes)
- dry mouth
- stuffed nose
- difficulty urinating
- blurred vision
- slowed breathing
Thioridazine may interfere with the results of home pregnancy tests. Talk to your doctor if you think you might be pregnant during your treatment with thioridazine. Do not try to test for pregnancy at home.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
¶This branded product is no longer on the market. Generic alternatives may be available.
AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Selected Revisions: May 16, 2011.