See Supplemental Patient Information
- Elderly patients with dementia-related psychosis are at an increased risk of death when treated with antipsychotic drugs [US Black Box Warning]
- This drug is not approved for the treatment of patients with dementia-related psychosis [US Black Box Warning]
- Potential for significant possibly life threatening proarrhythmic effects exists; reserve thioridazine for use in the treatment of schizophrenic patients who fail to show an acceptable response to adequate courses of therapy with other antipsychotic drugs, either because of insufficient efficacy or due to the inability to achieve an effective dose due to intolerable adverse effects from those drugs [US Black Box Warning]. Administer patients at least two trials, each with a different antipsychotic drug product, at an adequate dose, and for an adequate duration before initiating treatment. This drug is not evaluated systematically for the treatment of refractory schizophrenic patients and its efficacy in such patients is unknown
- This drug is associated with prolongation of the QTc interval in a dose related manner, Torsades de pointes type arrhythmias and sudden death [US Black Box Warning]. Bradycardia, hypokalemia, concomitant use of other drugs that prolong the QTc interval, presence of congenital prolongation of the QT interval, and use in patients with reduced activity of CYPP450 2D6 or its co-administration with drugs that may inhibit P450 2D6 or by some other mechanism interfering with the clearance of thioridazine are the associated risk factors for increasing risk of Torsades de pointes and/or sudden death
- Perform baseline ECG and measure serum potassium levels before considering therapy with this drug. Serum potassium should be within acceptable limit before initiating treatment and patients with a QTc interval >450 msec should not receive thioridazine therapy. Periodically monitor ECG’s and serum potassium during therapy, especially during a period of dose modifications. Discontinue therapy in patients having QTc interval >500 msec. Consider cardiac evaluation; in particular, Holter monitoring in patients experienced symptoms that may be associated with the occurrence of Torsades de pointes (e.g., dizziness, palpitations, or syncope)
- Risk of developing irreversible tardive dyskinesia increases as the duration of treatment and the total cumulative dose of antipsychotic drugs administered to the patient increases. Elderly women are more prone to syndrome of potentially irreversible, involuntary, dyskinetic movements. Syndrome may remit, partially or completely, if antipsychotic treatment is withdrawn
- Antipsychotic treatment may suppress (or partially suppress) the signs and symptoms of the syndrome and thereby may possibly mask the underlying process
- Prescribe this drug in a manner that is most likely to minimize the risk of tardive dyskinesia. Discontinue therapy on occurrence of signs and symptoms of tardive dyskinesia. Reserve chronic antipsychotic treatment for patients who suffer from a chronic illness that is known to respond to antipsychotic drugs, and for whom alternative, equally effective, but potentially less harmful therapy is not available or appropriate. Prescribe the smallest dose and the shortest course of therapy producing a satisfactory clinical response in patients who do require chronic therapy. Periodically reassessed need for continued treatment
- Consider discontinuation of therapy on development of signs and symptoms of tardive dyskinesia; however, some patients may require therapy despite the presence of the syndrome
- Patients having demonstrated a hypersensitivity reaction (e.g., blood dyscrasias, jaundice) are prone to demonstrate a reaction to others. Phenothiazines are capable of potentiating CNS depressants (e.g., anesthetics, opiates, alcohol, etc.) as well as atropine and phosphorus insecticides. Carefully consider benefit/risk while treating less severe disorders. Severe respiratory depression and respiratory arrest may occur when a patient is given a phenothiazine and a concomitant high dose of a barbiturate
- Administer this drug only when the benefits derived from therapy exceeds the possible risks to mother and fetus. Extrapyramidal and/or withdrawal symptoms may occur in neonates exposed to antipsychotic drugs, during the third trimester of pregnancy. Agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress and feeding disorder may occur in neonates. Some cases may require intensive care unit support and prolonged hospitalization
- Potentially fatal symptom complex sometimes referred to as neuroleptic malignant syndrome (NMS) has occurred in association with administration of antipsychotic drugs. Manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status, and evidence of autonomic instability. Additional signs including elevated creatinine phosphokinase, myoglobinuria (rhabdomyolysis), and acute renal failure have occurred
- Immediately discontinue antipsychotic drugs and other drugs not essential for concomitant therapy, provide intensive symptomatic treatment, carefully monitor patients and provide treatment for concomitant serious medical problems for management of NMS
- Carefully consider potential reintroduction of drug therapy in patients recovered from NMS as recurrences of NMS can occur
- Leukopenia and/or agranulocytosis and convulsive seizures may occur. Maintain anticonvulsant medication during treatment with thioridazine in schizophrenic patients with epilepsy
- Pigmentary retinopathy may occur primarily in patients taking higher than recommended doses
- Exercise caution while administering this drug in patients participating in activities requiring complete mental alertness (e.g., driving) and gradually increase dose in such patients
- Female patients are more prone for development of orthostatic hypotension. Avoid administration of epinephrine in the treatment of drug-induced hypotension
- Hyperprolactinemia may occur in association with therapy with this drug. Galactorrhea, amenorrhea, gynecomastia, and impotence may occur in patients receiving prolactin-elevating compounds. Long term hyperprolactinemia is associated with hypogonadism leading to decreased bone density in both female and male subjects
Cautions: Use cautiously in
- Impaired liver function
- Dementia (increased risk of mortality)
- Cardiovascular disease
- Cerebrovascular disease
- CNS depressant use
- Seizure history or risk of seizures
- Parkinson's disease
- Leukopenia
- History of drug induced leukopenia or neutropenia
- Prostatic hypertrophy
- Elderly patients (dose reduction recommended)
- History of breast cancer
Supplemental Patient Information
- Inform Patients that thioridazine is associated with potentially fatal heart rhythm disturbances
- Advise patients to inform the prescriber whether they are receiving thioridazine treatment before taking any new medication
Pregnancy Category:C
Breastfeeding: Safety unknown; no published experience with thioridazine, hence other agents might be preferred. This information is based upon LactMed database (available at http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT last accessed 7 April 2011).
