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Thioridazine

Last reviewed on RxList: 2/24/2017
Thioridazine Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

Last reviewed on RxList 02/13/2017

Thioridazine (thioridazine hydrochloride) is an antipsychotic drug used to treat schizophrenia. Thioridazine is available in generic form. Common side effects of thioridazine include:

Thioridazine may rarely cause a condition known as tardive dyskinesia. Tell your doctor if you develop unusual/uncontrolled movements (especially of the face, lips, tongue, arms or legs). Tell your doctor if you have rare but very serious side effects of thioridazine including:

  • signs of infection (e.g., fever, persistent sore throat), or
  • vision changes (e.g., vision loss, sudden difficulty seeing at night, brown-tinged vision).

The recommended dosage of Thioridazine is 50 to 100 mg three times a day to start and then 200 to 800 mg divided into two to four doses per day thereafter. Cabergoline, cisapride, duloxetine, fluoxetine, fluvoxamine, paroxetine, pergolide, pindolol, propranolol, and sibutramine may interact with Thioridazine. Tell your doctor all medications you use. Do not drive, use machinery, or do other activity requiring full alertness after using Thioridazine. Avoid sun exposure, tanning booths, and sunlamps when taking Thioridazine. If you are pregnant only use Thioridazine if clearly needed. Talk to your doctor about taking Thioridazine if you are breastfeeding.

Our Thioridazine (thioridazine hydrochloride) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Thioridazine Consumer Information

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using thioridazine and call your doctor at once if you have a serious side effect such as:

  • headache with chest pain and severe dizziness, fainting, fast or pounding heartbeats;
  • slow heart rate, weak pulse, fainting, slow breathing;
  • very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, feeling like you might pass out;
  • twitching or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs;
  • tremor (uncontrolled shaking), drooling, trouble swallowing, problems with balance or walking;
  • feeling restless, jittery, or agitated;
  • seizure (convulsions);
  • decreased night vision, tunnel vision, watery eyes, increased sensitivity to light;
  • pale skin, easy bruising or bleeding, fever, chills, flu symptoms, sores in your mouth and throat;
  • urinating less than usual or not at all; or
  • nausea and upper stomach pain, itching, and jaundice (yellowing of the skin or eyes).

Less serious side effects may include:

  • drowsiness;
  • dry mouth, stuffy nose;
  • vomiting, constipation, diarrhea;
  • breast swelling or discharge;
  • changes in your menstrual periods;
  • weight gain, swelling in your hands or feet;
  • impotence, trouble having an orgasm;
  • increased or decreased interest in sex; or
  • mild itching or skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Thioridazine (Thioridazine)

Thioridazine Professional Information

SIDE EFFECTS

In the recommended dosage ranges with thioridazine hydrochloride most side effects are mild and transient.

Central Nervous System: Drowsiness may be encountered on occasion, especially where large doses are given early in treatment. Generally, this effect tends to subside with continued therapy or a reduction in dosage. Pseudoparkinsonism and other extrapyramidal symptoms may occur but are infrequent. Nocturnal confusion, hyperactivity, lethargy, psychotic reactions, restlessness, and headache have been reported but are extremely rare.

Autonomic Nervous System: Dryness of mouth, blurred vision, constipation, nausea, vomiting, diarrhea, nasal stuffiness, and pallor have been seen.

Endocrine System: Galactorrhea, breast engorgement, amenorrhea, inhibition of ejaculation, and peripheral edema have been described.

Skin:Dermatitis and skin eruptions of the urticarial type have been observed infrequently. Photosensitivity is extremely rare.

Cardiovascular System: Thioridazine produces a dose related prolongation of the QTc interval, which is associated with the ability to cause torsade de pointes-type arrhythmias, a potentially fatal polymorphic ventricular tachycardia, and sudden death (see WARNINGS). Both torsade de pointes-type arrhythmias and sudden death have been reported in association with thioridazine. A causal relationship between these events and thioridazine therapy has not been established but, given the ability of thioridazine to prolong the QTc interval, such a relationship is possible. Other ECG changes have been reported (see Phenothiazine Derivatives: Cardiovascular Effects).

Other: Rare cases described as parotid swelling have been reported following administration of thioridazine.

Post Introduction Reports: These are voluntary reports of adverse events temporally associated with thioridazine that were received since marketing, and there may be no causal relationship between thioridazine use and these events: priapism.

Phenothiazine Derivatives: It should be noted that efficacy, indications, and untoward effects have varied with the different phenothiazines. It has been reported that old age lowers the tolerance for phenothiazines. The most common neurological side effects in these patients are parkinsonism and akathisia. There appears to be an increased risk of agranulocytosis and leukopenia in the geriatric population. The physician should be aware that the following have occurred with one or more phenothiazines and should be considered whenever one of these drugs is used:

Autonomic Reactions:Miosis, obstipation, anorexia, paralytic ileus.

Cutaneous Reactions: Erythema, exfoliative dermatitis, contact dermatitis.

Blood Dyscrasias: Agranulocytosis, leukopenia, eosinophilia, thrombocytopenia, anemia, aplastic anemia, pancytopenia.

Allergic Reactions: Fever, laryngeal edema, angioneurotic edema, asthma.

Hepatotoxicity: Jaundice, biliary stasis.

Cardiovascular Effects: Changes in the terminal portion of the electrocardiogram to include prolongation of the QT interval, depression and inversion of the T wave, and the appearance of a wave tentatively identified as a bifid T wave or a U wave have been observed in patients receiving phenothiazines, including thioridazine. To date, these appear to be due to altered repolarization, not related to myocardial damage, and reversible. Nonetheless, significant prolongation of the QT interval has been associated with serious ventricular arrhythmias and sudden death (see WARNINGS). Hypotension, rarely resulting in cardiac arrest, has been reported.

Extrapyramidal Symptoms: Akathisia, agitation, motor restlessness, dystonic reactions, trismus, torticollis, opisthotonus, oculogyric crises, tremor, muscular rigidity, akinesia.

Tardive Dyskinesia:Chronic use of antipsychotics may be associated with the development of tardive dyskinesia. The salient features of this syndrome are described in the WARNINGS section and subsequently.

The syndrome is characterized by involuntary choreoathetoid movements which variously involve the tongue, face, mouth, lips, or jaw (e.g., protrusion of the tongue, puffing of cheeks, puckering of the mouth, chewing movements), trunk, and extremities. The severity of the syndrome and the degree of impairment produced vary widely.

The syndrome may become clinically recognizable either during treatment, upon dosage reduction, or upon withdrawal of treatment. Movements may decrease in intensity and may disappear altogether if further treatment with antipsychotics is withheld. It is generally believed that reversibility is more likely after short rather than long-term antipsychotic exposure. Consequently, early detection of tardive dyskinesia is important. To increase the likelihood of detecting the syndrome at the earliest possible time, the dosage of antipsychotic drug should be reduced periodically (if clinically possible) and the patient observed for signs of the disorder. This maneuver is critical, for antipsychotic drugs may mask the signs of the syndrome.

Neuroleptic Malignant Syndrome (NMS): Chronic use of antipsychotics may be associated with the development of Neuroleptic Malignant Syndrome. The salient features of this syndrome are described in the WARNINGS section and subsequently. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status, and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis, and cardiac dysrhythmias).

Endocrine Disturbances:Menstrual irregularities, altered libido, gynecomastia, lactation, weight gain, edema. False positive pregnancy tests have been reported.

Urinary Disturbances: Retention, incontinence.

Others: Hyperpyrexia. Behavioral effects suggestive of a paradoxical reaction have been reported. These include excitement, bizarre dreams, aggravation of psychoses, and toxic confusional states. More recently, a peculiar skin-eye syndrome has been recognized as a side effect following long-term treatment with phenothiazines. This reaction is marked by progressive pigmentation of areas of the skin or conjunctiva and/or accompanied by discoloration of the exposed sclera and cornea. Opacities of the anterior lens and cornea described as irregular or stellate in shape have also been reported. Systemic lupus erythematosus-like syndrome.

Read the entire FDA prescribing information for Thioridazine (Thioridazine)

Related Resources for Thioridazine

Read the Thioridazine User Reviews »

© Thioridazine Patient Information is supplied by Cerner Multum, Inc. and Thioridazine Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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