What is thioridazine?

Thioridazine is in a class of drugs called phenothiazines. It works by changing the actions of chemicals in the brain.

Thioridazine is used to treat psychotic disorders, such as schizophrenia. Thioridazine is generally reserved for people who do not respond to other drugs or who cannot take other drugs due to side effects.

Thioridazine may also be used for purposes other than those listed in this medication guide.

What is the most important information I should know about thioridazine?

Do not take thioridazine if you have any of the following conditions or a history of these conditions: heart disease; an irregular heartbeat or a history of irregular heartbeats; a history of prolonged QT intervals; a family history of congenital long QT syndrome; or other heartbeat disturbances. These conditions may increase the risk of irregular heartbeats, heart attack, and death while taking thioridazine. Do not take thioridazine with any of the following drugs: psychiatric medications such as fluoxetine (Prozac), paroxetine (Paxil, Paxil CR), and fluvoxamine (Luvox); or blood pressure medications such as pindolol (Visken) or propranolol (Inderal, Inderal LA, others). Taken with any of these drugs, thioridazine may cause irregular heartbeats that could lead to death. This is not a complete list of drugs that may interact with thioridazine and cause heart problems. Talk to your doctor or pharmacist before taking any other prescription or over-the-counter medications. Thioridazine may interact with other drugs that cause drowsiness, including alcohol, antidepressants, antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants. Dangerous sedation, dizziness, or drowsiness may occur if thioridazine is taken with alcohol or any of these medications. Talk to your doctor before taking thioridazine in combination with alcohol or any other medicines. Use caution when driving, operating machinery, or performing other hazardous activities. Thioridazine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Dizziness may be more likely to occur when you rise from a sitting or lying position. Rise slowly to prevent dizziness and a possible fall.

Call your doctor immediately if you have uncontrollable movements of the mouth, tongue, cheeks, jaw, arms, or legs; fever; muscle rigidity; sweating; irregular pulse; or fast or irregular heartbeats.

What should I discuss with my healthcare provider before taking thioridazine?

Do not take thioridazine if you have any of the following conditions or a history of these conditions: heart disease; an irregular heartbeat or a history of irregular heartbeats; a history of prolonged QT intervals; a family history of congenital long QT syndrome; or other heartbeat disturbances. These conditions may increase the risk of irregular heartbeats, heart attack, and death while taking thioridazine. Do not take thioridazine with any of the following drugs: psychiatric medications such as fluoxetine (Prozac), paroxetine (Paxil, Paxil CR), and fluvoxamine (Luvox); or blood pressure medications such as pindolol (Visken) or propranolol (Inderal, Inderal LA, others). Taken with any of these drugs, thioridazine may cause irregular heartbeats that could lead to death. This is not a complete list of drugs that may interact with thioridazine and cause heart problems. Talk to your doctor or pharmacist before taking any other prescription or over-the-counter medications.

Before taking thioridazine, tell your doctor if you have

a bone marrow disease,

glaucoma,

seizures,

Parkinson's disease,

an enlarged prostate or difficulty urinating,

liver disease, or

kidney disease.

You may not be able to take thioridazine, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

It is not known whether thioridazine will harm an unborn baby. Do not take thioridazine without first talking to your doctor if you are pregnant or could become pregnant during treatment. It is not known whether thioridazine passes into breast milk. Do not take thioridazine without first talking to your doctor if you are breast-feeding a baby. If you are over 60 years of age, you may be more likely to experience side effects from thioridazine. Your doctor may prescribe a lower dose of this medication or you may require special monitoring during treatment.

How should I take thioridazine?

Take thioridazine exactly as directed by your doctor. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you.

Your doctor may want to monitor your heartbeats and obtain a blood sample before starting and periodically during treatment with thioridazine.

Take each dose with a full glass of water.

Thioridazine can be taken with or without food.

Shake the suspension (Mellaril-S) well before using it.

To ensure that you get a correct dose, measure the liquid forms of thioridazine with a dropper or a special dose-measuring spoon or cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

The liquid concentrate can be mixed with 2 to 4 ounces of water or a suitable juice. Each dose should be mixed just prior to taking.

Do not let the liquid concentrate touch your skin or clothes.

Throw away any discolored liquid.

Do not stop taking thioridazine without first talking to your doctor. It may be several weeks before you begin to feel better, and you may require continuous treatment for quite some time. Store thioridazine at room temperature away from moisture and heat. Store the liquid in a light-resistant container.

What happens if I miss a dose?

Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and take only the next regularly scheduled dose. Do not take a double dose of this medication.

What happens if I overdose?

Seek emergency medical attention.

Symptoms of a thioridazine overdose include uncontrollable movements, agitation, seizures, severe dizziness or fainting, coma, very deep sleep, irregular heartbeats, and high or low body temperature.

What other drugs will affect thioridazine?

Do not take thioridazine with any of the following drugs: psychiatric medications such as fluoxetine (Prozac), paroxetine (Paxil, Paxil CR), and fluvoxamine (Luvox); or blood pressure medications such as pindolol (Visken) or propranolol (Inderal, Inderal LA, others). Taken with any of these drugs, thioridazine may cause irregular heartbeats that could lead to death. This is not a complete list of drugs that may interact with thioridazine and cause heart problems. Talk to your doctor or pharmacist before taking any other prescription or over-the-counter medications.

Thioridazine may interact with other drugs that cause drowsiness, including alcohol, antidepressants, antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants. Dangerous sedation, dizziness, or drowsiness may occur if thioridazine is taken with alcohol or any of these medications. Talk to your doctor before taking thioridazine in combination with alcohol or any other medicines.

Thioridazine also interacts with many medications other than the ones listed here. Before taking thioridazine, tell your doctor about all other medicines you are taking. During treatment, do not start taking any new drug or herbal product without first talking to your doctor.

What should I avoid while taking thioridazine?

Use caution when driving, operating machinery, or performing other hazardous activities. Thioridazine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.

Dizziness may be more likely to occur when you rise from a sitting or lying position. Rise slowly to prevent dizziness and a possible fall.

Thioridazine may interact with other drugs that cause drowsiness, including alcohol, antidepressants, antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants. Dangerous sedation, dizziness, or drowsiness may occur if thioridazine is taken with alcohol or any of these medications. Talk to your doctor before taking thioridazine in combination with alcohol or any other medicines. Avoid prolonged exposure to sunlight. Thioridazine may increase the sensitivity of the skin to sunlight. Use a sunscreen and wear protective clothing when sun exposure is unavoidable.

Thioridazine side effects

If you experience any of the following serious side effects, stop taking thioridazine and seek emergency medical treatment or contact your doctor immediately:

• an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);
• uncontrollable movements of the mouth, tongue, cheeks, jaw, arms, or legs;
• fever;
• muscle rigidity;
• muscle spasms of the face or neck;
• sweating;
• irregular pulse;
• fast or irregular heartbeats.
• severe restlessness or tremor;
• severe drowsiness;
• blurred vision;
• dizziness or fainting; or
• a rash.
Other, less serious side effects may be more likely to occur. Continue to take thioridazine and talk to your doctor if you experience
• dry mouth, stuffy nose;
• constipation;
• mild restlessness, drowsiness, or tremor;
• decreased sex drive;
• increased appetite;
• difficult urination or dark urine; or
• menstrual irregularities or swollen breasts.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.