Thioridazine

Brand names

• Apo-Thioridazine
• Mellaril
• Mellaril-S
• Millazine
• Novo-Ridazine
• PMS-Thioridazine
• SK-Thioridazine

Usage

To treat moderate to severe psychiatric conditions including schizophrenia, manic states, anxiety, depression, sleep disturbances, and medicament-induced psychosis. It is also used to treat extreme behavior problems in children, as well as agitation and confusion in the elderly.

How it works

Thioridazine blocks receptors of dopamine (a chemical that aids in the transmission of nerve impulses) in the central nervous system. Presumably, this produces a tranquilizing and antipsychotic effect.

Side effects

Serious

Rapid heartbeat, profuse sweating, seizures, difficulty breathing, neck stiffness, swelling of the tongue, difficulty swallowing. Also a rare condition can develop called neuroleptic malignant syndrome, characterized by stiffness or spasms of the muscles, high fever, and confusion or disorientation.

Common

Dizziness or faintness, drowsiness, constipation, decreased sweating, dry mouth, nasal congestion, shaking or trembling of the hands, stiffness, stooped posture.

Less common

Menstrual irregularities, sexual dysfunction, unusual milk secretion, breast pain or swelling, unexpected weight gain, difficult urination.

Possible interactions

Other medicaments:

Thioridazine may increase the effects of:

• all atropinelike medicaments and cause nervous system toxicity.
• all sedative medicaments, especially meperidine (Demerol), and cause excessive sedation.

Thioridazine may decrease the effects of:

• amphetamines.
• bromocriptine (Parlodel).
• guanethidine (Ismelin, Esimil) and reduce its effectiveness in lowering blood pressure.
• oral hypoglycemic agents.
• quetiapine (Seroquel).

Thioridazine taken concurrently with:

• ascorbic acid (vitamin C) may result in decreased thioridazine therapeutic benefits.
• cisapride (Propulsid) may lead to abnormal heartbeats.
• gatifloxacin (Tequin), grepafloxacin (Raxar), moxifloxacin (Avelox) or sparfloxacin (Zagam) may result in abnormal heartbeats.
• lithium (Lithobid, Lithotabs) may impair the effectiveness of lithium and cause nervous system toxicity.
• monoamine oxidase (MAO) inhibitors may lead to prolonged thioridazine effects.
• phenytoin (Dilantin) or fosphenytoin (Cerebyx) may increase or decrease blood levels.
• ritonavir (Norvir) and perhaps other protease inhibitors may lead to toxicity.
• tramadol (Ultram) may increase seizure risk.
• zotepine (Nipolept) can increase seizure risks.

The following medicaments may decrease the effects of thioridazine:

• antacids containing aluminum and/or magnesium.
• barbiturates.
• benztropine (Cogentin).
• disulfiram (Antabuse).
• trihexyphenidyl (Artane).

Herbal medicines or minerals:

Since thioridazine and St. John's wort may act to worsen sensitivity to the sun, caution is advised. Kava and valerian may worsen drowsiness. Since part of the way that ginseng works is as an MAO inhibitor, combination with this medicine is not advisable.
A riboflavin (vitamin B2) supplement should be taken with long-term use. Vitamin E may help reduce risk of movement disorders. Talk to your doctor.

Alcohol:

Alcohol can increase the sedative action of phenothiazines and accentuate their depressant effects on brain function and blood pressure. Phenothiazines can increase the intoxicating effects of alcohol.

Tobacco smoking:

There may be a reduction of drowsiness from this medicament if you smoke.

Marijuana smoking:

Moderate increase in drowsiness; accentuation of orthostatic hypotension; increased risk of precipitating latent psychoses, confusing the interpretation of mental status and medicament responses.

Exposure to sun:

Use caution-some phenothiazines can cause photosensitivity.

Exposure to heat:

Use caution and avoid excessive heat as much as possible. This medicament may impair the regulation of body temperature and increase the risk of heatstroke.

Exposure to cold:

This medicament can increase the risk of hypothermia in the elderly.

Discontinuation:

After long-term use, do not stop this medicament suddenly. Gradual withdrawal over 2 to 3 weeks under physician supervision is recommended. Do not discontinue this medicament without your physician's knowledge and approval.

Comments