Thioridazine rarely has caused very serious (possibly fatal) irregular heartbeat (QT prolongation in the EKG). Therefore, it should be used only in patients who have not shown improvement with at least 2 other antipsychotic medications or who cannot tolerate other antipsychotic medications. This medication should not be used with other medications that can also cause a slow or irregular heartbeat. (See also Drug Interactions.)
There may be a slightly increased risk of serious, possibly fatal side effects (such as heart failure, fast/irregular heartbeat, pneumonia) when this medication is used by older adults with dementia. This medication is not approved for the treatment of dementia-related behavior problems. Discuss the risks and benefits of this medication, as well as other effective and possibly safer treatments for dementia-related behavior problems, with the doctor.Who should not take thioridazine?
This medication is used to treat certain mental/mood disorders (e.g., schizophrenia). This medication helps you to think more clearly, feel less nervous, and take part in everyday life. It can also help prevent suicide in people likely to harm themselves and reduce aggression and the desire to hurt others. It can help decrease your negative thoughts and hallucinations. Thioridazine belongs to a class of drugs known as phenothiazines.
OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This drug may also be used for short periods of time to treat very severe depression when the patient is also anxious.
Take this medication by mouth with or without food, usually 2-4 times a day or as directed by your doctor.
Dosage is based on your medical condition and response to therapy. Once your condition improves and you are better for a while, your doctor may work with you to reduce your regular dose. This may be done over time. Do not stop your medication or lower your dose without talking with your doctor first. Some conditions may become worse when the drug is stopped abruptly. Your dose may need to be gradually reduced.
Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same time(s) each day.
Inform your doctor if your condition persists or worsens.
Tell your doctor if any of these serious side effects occur: shakiness (tremors), mask-like facial expression, jerking movements while walking.
Thioridazine may rarely cause a condition known as tardive dyskinesia. In some cases this condition may be permanent. Tell your doctor immediately if you develop any unusual/uncontrolled movements (especially of the face, lips, tongue, arms or legs).
In rare cases, thioridazine may increase your level of a certain chemical made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor immediately.
Tell your doctor immediately if any of these rare but very serious side effects occur: signs of infection (e.g., fever, persistent sore throat), vision changes (e.g., vision loss, sudden difficulty seeing at night, brown-tinged vision).
This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms: fever, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, change in the amount of urine.
A very serious allergic reaction to this drug is unlikely. Seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
In the US -
Before taking thioridazine, tell your doctor or pharmacist if you are allergic to it; or to other phenothiazines (e.g., chlorpromazine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: a certain severe nervous system problem (severe CNS depression), severe blood pressure problems.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: certain blood problems (e.g., low white blood cell count), Parkinson's disease, history of seizures, low enzymes needed to remove drugs from the body (slow hydroxylator).
Thioridazine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.
The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using thioridazine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using thioridazine safely.
This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
To decrease dizziness and lightheadedness, get up slowly when rising from a seated or lying position.
Before having surgery, tell your doctor or dentist that you are taking this medication.
This medication may make you more sensitive to the sun. Avoid prolonged sun exposure, tanning booths, and sunlamps. Use a sunscreen and wear protective clothing when outdoors.
Older adults may be more sensitive to the side effects of this drug, especially dizziness (more likely when standing up), drowsiness, confusion, constipation, difficulty urinating, and QT prolongation (see above). Dizziness, drowsiness, and confusion can increase the risk of falling.
During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away.
Since untreated mental/mood problems (such as schizophrenia, depression) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.
It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include: anticholinergic medications (e.g., belladonna alkaloids, atropine, scopolamine), carbamazepine, cabergoline, cisapride, duloxetine, guanethidine, guanadrel, lithium, mirabegron, medications for Parkinson's disease (e.g., levodopa, benztropine), pergolide, pindolol, propranolol, certain SSRI antidepressants (e.g., fluoxetine, fluvoxamine, paroxetine).
Many drugs besides thioridazine may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), among others. Therefore, before using thioridazine, report all medications you are currently using to your doctor or pharmacist.
Also report the use of drugs which might increase seizure risk (decrease seizure threshold) when combined with this drug such as isoniazid, haloperidol, theophylline, tramadol, or tricyclic antidepressants (e.g., amitriptyline, nortriptyline), among others.
Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-seizure drugs (e.g., phenytoin), medicine for sleep or anxiety (e.g., alprazolam, diazepam, zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., chlorpromazine, risperidone, trazodone).
Check the labels on all your medicines (e.g., cough-and-cold products) because they may contain drowsiness-causing ingredients. Ask your pharmacist about the safe use of those products.
If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
Do not share this medication with others.
Laboratory and/or medical tests (e.g., eye exams, potassium levels, EKG) may be performed from time to time to monitor your progress or check for side effects. Consult your doctor for more details.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Information last revised March 2015. Copyright(c) 2015 First Databank, Inc.
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