Thioridazine Full Prescribing Information
Brand Name: Mellaril
Generic Name: Thioridazine
Thioridazine (Mellaril) for treatment of schizophrenia patients who fail to respond to treatment with other antipsychotic drugs. Uses, dosage, side effects of Mellaril.
Mellaril patient information (in plain English)
MELLARIL® (THIORIDAZINE HCl) HAS BEEN SHOWN TO PROLONG THE QTc INTERVAL IN A DOSE RELATED MANNER, AND DRUGS WITH THIS POTENTIAL, INCLUDING MELLARIL, HAVE BEEN ASSOCIATED WITH TORSADE DE POINTES- TYPE ARRHYTHMIAS AND SUDDEN DEATH. DUE TO ITS POTENTIAL FOR SIGNIFICANT, POSSIBLY LIFE-THREATENING, PROARRHYTHMIC EFFECTS, MELLARIL SHOULD BE RESERVED FOR USE IN THE TREATMENT OF SCHIZOPHRENIC PATIENTS WHO FAIL TO SHOW AN ACCEPTABLE RESPONSE TO ADEQUATE COURSES OF TREATMENT WITH OTHER ANTIPSYCHOTIC DRUGS, EITHER BECAUSE OF INSUFFICIENT EFFECTIVENESS OR THE INABILITY TO ACHIEVE AN EFFECTIVE DOSE DUE TO INTOLERABLE ADVERSE EFFECTS FROM THOSE DRUGS. (SEE WARNINGS, CONTRAINDICATIONS, AND INDICATIONS).
Thioridazine is a phenothiazine used to treat emotional disorders such as schizophrenia and other psychotic disturbances, as well as depression and anxiety.
At low and medium doses, Thioridazine relieves tension and anxiety. At higher doses, thioridazine is effective in controlling the symptoms of psychotic disorders like schizophrenia.
Maximum plasma concentrations are reached 2 to 4 hours after ingestion.
Anxiety, tension, mixed states of anxiety and depression, agitation, emotional disturbances accompanied by anxiety and tension, psychosomatic disorders, sleep disturbances.
In geriatric patients, Thioridazine is helpful with senile agitation and confusional states, anxiety and mixed states of anxiety and depression, insomnia.
Children: Not recommended for those under 1 year old. Indicated for anxiety, tension, difficulties with concentration, sleep disturbances, behavioral disorders such as agitation, hyperactivity or aggressiveness.
Thioridazine is particularly useful: in chronic hospitalized psychotic patients; in psychotic outpatients; in geriatric patients suffering from severe agitation, anxiety or mixed states of anxiety and depression, often associated with various degrees of an organic brain syndrome; during alcohol withdrawal for the relief of symptoms such as anxiety, agitation, hostility, or hallucinations; as an adjuvant treatment in agitated depression; in children with severe behavioral disorders such as emotional instability, hyperexcitability, excessive motor activity, and aggressiveness.
Mellaril® (thioridazine HCl) use should be avoided in combination with other drugs that are known to prolong the QTc interval and in patients with congenital long QT syndrome or a history of cardiac arrhythmias.
Reduced cytochrome P450 2D6 isozyme activity drugs that inhibit this isozyme (e.g., fluoxetine and paroxetine) and certain other drugs (e.g., fluvoxamine, propranolol, and pindolol) appear to appreciably inhibit the metabolism of thioridazine. The resulting elevated levels of thioridazine would be expected to augment the prolongation of the QTc interval associated with Mellaril and may increase the risk of serious, potentially fatal, cardiac arrhythmias, such as torsade de pointes-type arrhythmias. Such an increased risk may result also from the additive effect of co-administering Mellaril with other agents that prolong the QTc interval. Therefore, Mellaril is contraindicated with these drugs as well as in patients, comprising about 7% of the normal population, who are known to have a genetic defect leading to reduced levels of activity of P450 2D6 (see WARNINGS and PRECAUTIONS).
Thioridazine (Mellaril) is contraindicated in patients known to be hypersensitive to it.
Contraindicated in patients with severe CNS depression, bone marrow depression, or a history of blood dyscrasia.
Children: Not recommended for those under 1 year old.
The drug is contraindicated during the acute recovery period after a myocardial infarction.
There are reports of sudden and unexplained death, apparently due to arrhythmias or cardiac arrest. Previous brain damage or seizures may also be predisposing factors.
Mellaril® (thioridazine HCl) is indicated for the management of schizophrenic patients who fail to respond adequately to treatment with other antipsychotic drugs. Due to the risk of significant, potentially life-threatening, proarrhythmic effects with Mellaril treatment, Mellaril should be used only in patients who have failed to respond adequately to treatment with appropriate courses of other antipsychotic drugs, either because of insufficient effectiveness or the inability to achieve an effective dose due to intolerable adverse effects from those drugs. Consequently, before initiating treatment with Mellaril, it is strongly recommended that a patient be given at least 2 trials, each with a different antipsychotic drug product, at an adequate dose, and for an adequate duration (see WARNINGS and CONTRAINDICATIONS).
However, the prescriber should be aware that Mellaril has not been systematically evaluated in controlled trials in treatment refractory schizophrenic patients and its efficacy in such patients is unknown.
Seizures: High doses should be avoided in patients with a history of seizures.
Extreme caution should be used when this drug is given to: patients with cardiovascular disease.
Hypotension may occur, especially in females, the elderly, and in alcoholic patients.
Caution is required in patients with narrow-angle glaucoma, prostatic hypertrophy, or cardiovascular disease.
Thioridazine may induce cardiac arrhythmias.
Convulsive seizures have been infrequently reported. However, thioridazine has been shown to be helpful in the treatment of behavioral disorders in epileptic patients. In such cases, anticonvulsant medication should be continued and dosage adjustment considered
Pigmentary retinopathy has been observed after long-term treatment, mostly in patients receiving doses exceeding the recommended maximum of 800 mg/day. Patients receiving higher doses of phenothiazines for prolonged periods should have complete eye examinations at regular intervals.
Patients with liver disease need regular monitoring of liver function.
Usage in Children:: Do not give to children under 1 year old.
Pregnancy and Withdrawl: There have been no well-controlled studies conducted with pregnant women to determine the effect of thioridazine on the fetus. Therefore, thioridazine should be used in women who are or might become pregnant only if the clinical condition clearly justifies potential risk to the fetus.
Limited data suggest that thioridazine is likely to be excreted in human breast milk. As a general rule, a woman taking a drug should not nurse since the possibility exists that the drug may be excreted in breast milk and be harmful to the child.
Interference with Cognitive or Motor Performance: Since thioridazine may impair the mental and/or physical abilities required for the performance of potentially hazardous tasks, such as operating an automobile or machinery, the patient should be cautioned accordingly.
Phenothiazines may enhance the CNS-depressant effects of alcohol, antihistamines and other CNS depressants as well as atropine and phosphorus insecticides; the antimuscarinic effects of anticholinergic agents; and the inhibitory cardiac effects of quinidine.
Phenothiazines may reduce the antiparkinsonian effects of levodopa.
Concomitant use of lithium may aggravate extrapyramidal symptoms and neurotoxicity caused by neuroleptic agents.
Thioridazine may lower the seizure threshold in epileptic patients.
BEFORE USING THIS MEDICINE: INFORM YOUR DOCTOR OR PHARMACIST of all prescription and over-the-counter medicine that you are taking. This includes guanethidine, and medicines for high blood pressure, heart conditions, depression, and bladder or bowel spasms. Inform your doctor of any other medical conditions including seizure disorders, depression, allergies, pregnancy, or breast-feeding.
Do not become overheated in hot weather, during exercise, or other activities since heat stroke may occur while you are using this medicine. This medicine may cause increased sensitivity to the sun. Avoid exposure to the sun or sunlamps until you know how you react to this medicine. Use a sunscreen or protective clothing if you must be outside for a prolonged period.
DO NOT DRINK ALCOHOL while you are taking this medicine.
CHECK WITH YOUR DOCTOR AS SOON AS POSSIBLE if you experience changes in vision; changes in breasts; changes in menstrual period; sore throat; inability to move eyes; muscle spasms of face, neck, or back; difficulty swallowing; mask-like face; tremors of hands; restlessness; tension in legs; shuffling walk or stiff arms or legs; puffing of cheeks; lip smacking or puckering; twitching or twisting movements; or weakness of arms or legs. If you notice other effects not listed above, contact your doctor, nurse, or pharmacist.
Side effects that may go away during treatment, include drowsiness, dizziness, nasal congestion, blurred vision, dry mouth, or constipation. If they continue or are bothersome, check with your doctor.
Although the listing which follows includes a few adverse reactions which have not been reported with this specific drug, the pharmacological similarities among the phenothiazine drugs require that each of the reactions be considered when Thioridazine is administered.
Cardiovascular: Orthostatic hypotension, tachycardia, ECG changes.
Psychiatric: Oversedation, impaired psychomotor function, paradoxical effects (such as agitation, excitement, insomnia, bizarre dreams, aggravation of psychotic symptoms), toxic confusional states.
Neurological: Dry mouth, fainting, nasal stuffiness, photophobia, miosis, blurred vision.
Allergic: Fever, laryngeal edema, angioneurotic edema, asthma.
Hematologic: Bone marrow depression including agranulocytosis; eosinophilia; purpura; thrombocytopenia.
Gastrointestinal: Anorexia, gastric irritation, nausea, vomiting, constipation, diarrhea, obstipation, paralytic ileus, pallor.
Endocrine: Menstrual irregularities, altered libido, gynecomastia, galactorrhea, breast engorgement, weight change, edema, false positive pregnancy tests, disturbances of erection and of ejaculation (failure or priapism).
Urinary: Retention, incontinence.
Signs and Symptoms
Symptoms of overdose may include restlessness, muscle spasms, tremors, twitching, deep sleep or loss of consciousness, and seizures.
If you or someone you know may have used more than the recommended dose of this medicine, contact your local poison control center or emergency room immediately.
Maintain adequate airway, empty stomach contents, and treat symptomatically.
There is no specific antidote for Thioridazine poisoning. Treatment should be supportive and in response to clinical signs and symptoms. Respiration, pulse and blood pressure should be monitored and supported by general measures when necessary. Immediate gastric lavage should be performed. I.V. fluid should be administered and an adequate airway maintained.
Do not exceed the recommended dosage or take this medicine for longer than prescribed.
- Follow the directions for using this medicine provided by your doctor.
- Store this medicine at room temperature, in a tightly-closed container, away from heat and light.
- If you miss a dose of this medicine, take it as soon as possible. If you are taking 1 dose at bedtime and do not remember until the next morning, skip the missed dose and go back to your regular dosing schedule.
Additional Information:: Do not share this medicine with others for whom it was not prescribed. Do not use this medicine for other health conditions. Keep this medicine out of the reach of children.
IF USING THIS MEDICINE FOR AN EXTENDED PERIOD OF TIME, obtain refills before your supply runs out.
For oral dosage form (suspension, solution, or tablets)- For nervous, mental, or emotional disorders:
Outpatients: Initially 75 mg/day increased to 150 mg/day. Dosages over 200 mg/day are not recommended. Maintenance, 50-150 mg/day.
Adults and teenagers: At first, 25 to 100 milligrams (mg) three times a day. Your doctor may increase your dose if needed. However, the dose is usually not more than 800 mg a day.
Elderly: Most geriatric patients will require 25 mg 3 times daily.
Children 2 to 12 years of age: Dose is based on body weight or size and must be determined by your doctor. The usual dose is 10 to 25 mg two or three times a day.
Children up to 2 years of age: Dose must be determined by your doctor.
Solution: Each mL of solution contains: Thioridazine HCl USP 30 mg. Also contains ethanol 24.5 mg and parabens. Bottles of 115 mL with calibrated droppers.
Suspension: Each 5 mL of fruit flavored suspension contains: Thioridazine (base) 10 mg. Also contains ethanol 25.6 mg and parabens. Bottles of 230 mL.
Tablets:: available iin 10 mg, 15 mg, 25 mg, 50 mg, 75 mg, 100 mg, 150 mg, 200 mg.
Mellaril patient information (in plain English)
The information in this monograph is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects. This information is generalized and is not intended as specific medical advice. If you have questions about the medicines you are taking or would like more information, check with your doctor, pharmacist, or nurse.
Copyright © 2007 Healthyplace Inc. All rights reserved.
Last Updated: 09 April 2017
Reviewed by Harry Croft, MD