Torecan: Uses, Side Effects, and Dosage Guide

Torecan ( Thiethylperazine) is a phenothiazine derivative medication indicated for the treatment of nausea and vomiting. It acts as an antiemetic by blocking dopamine receptors in the brain. Torecan has been used in clinical practice for many years but the brand name version was discontinued by the manufacturer in the United States. Generic versions of Torecan are still available for prescription use under the guidance of a qualified healthcare provider.

Pharmacology

Torecan ( Thiethylperazine) is a phenothiazine derivative that acts as an antagonist at dopamine receptors, specifically DRD1, DRD2 and DRD4. By blocking these receptors, Torecan suppresses the activity of the chemoreceptor trigger zone in the brain, resulting in its antiemetic effects. The exact mechanism of action of Torecan in reducing nausea and vomiting is not fully understood but is thought to involve central nervous system (CNS) depression.

Medical Uses

Torecan is indicated for the treatment of nausea and vomiting from various causes, including:

• Motion sickness
• Migraine headaches
• Post-operative nausea and vomiting
• Chemotherapy-induced nausea and vomiting
• Radiation therapy-induced nausea and vomiting

Torecan may also be used off-label for other conditions causing nausea and vomiting at the discretion of the prescribing physician.

Dosage and Administration

The typical adult dose of Torecan for nausea and vomiting is 10 mg orally or intramuscularly, up to three times daily as needed. The maximum daily dose should not exceed 30 mg. Lower doses may be used in pediatric patients or those with renal or hepatic impairment. Torecan is available as tablets for oral administration and as a solution for intramuscular injection.

Side Effects

Common side effects of Torecan include:

• Drowsiness
• Dizziness
• Dry mouth
• Blurred vision
• Constipation

More serious side effects may include:

• Extrapyramidal symptoms (e.g. dystonia, akathisia)
• Neuroleptic malignant syndrome
• Tardive dyskinesia
• QT prolongation
• Seizures

Patients experiencing severe or persistent side effects should contact their healthcare provider immediately. Dose adjustments or discontinuation of Torecan may be necessary.

Contraindications

Torecan is contraindicated in patients with known hypersensitivity to thiethylperazine or other phenothiazine derivatives. It should be used with caution in patients with severe CNS depression, bone marrow depression, cardiovascular disease, and liver or kidney impairment. Torecan should not be used in comatose states or in the presence of large amounts of CNS depressants like alcohol.

Interactions

Torecan may interact with other medications, including:

• Other CNS depressants (e.g. alcohol, opioids, sedatives)
• Anticholinergic drugs
• Antipsychotic medications
• Lithium
• Tramadol

Patients should inform their doctor of all medications they are taking before starting treatment with Torecan. Dose adjustments may be necessary to minimize the risk of adverse interactions.

Patient Information

Patients should take Torecan exactly as prescribed by their doctor. The medication may be taken with or without food. If a dose is missed, the patient should take it as soon as they remember unless it is almost time for the next dose. Patients should not take extra medicine to make up for a missed dose.

Patients should be advised not to drive or operate heavy machinery until they know how Torecan affects them as it may cause drowsiness and impair alertness. Alcohol should be avoided while taking Torecan.

Special Populations

Pediatric Use

Safety and efficacy of Torecan in pediatric patients have not been established. Use in children should be avoided unless the potential benefits outweigh the risks.

Geriatric Use

Elderly patients may be more sensitive to the effects of Torecan, especially the anticholinergic effects. Lower initial doses and careful monitoring are recommended in this population.

Pregnancy and Lactation

Torecan is a pregnancy category C drug. It should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. It is not known if Torecan is excreted in breast milk. Nursing mothers should either discontinue the drug or stop breastfeeding.

Clinical Studies

The efficacy of Torecan in reducing nausea and vomiting has been demonstrated in several clinical trials. A double-blind study comparing Torecan with placebo and perphenazine found that both active drugs were significantly more effective than placebo in controlling emesis. Torecan was found to be as effective as perphenazine with a similar side effect profile.

Discontinuation and Availability

The brand name version of Torecan was discontinued by the manufacturer, Sanofi-Aventis, in 2004. Generic versions of thiethylperazine are still available in the United States for prescription use. Patients who have been prescribed the brand name drug will need to switch to a generic version in consultation with their healthcare provider.

Case Studies and Reports

Several case reports have described unusual or severe adverse effects associated with Torecan use. These include reports of dystonic reactions and oculogyric crises in pediatric patients treated with Torecan for vomiting. Prescribers should be aware of the potential for such reactions and monitor patients closely, especially when initiating treatment.

Historical Context

Thiethylperazine was first synthesized in the late 1950s and was introduced to the U.S. market as Torecan in the 1960s. It belongs to the phenothiazine class of antipsychotics which were among the first drugs used to treat psychosis. The use of phenothiazines expanded to include antiemetic indications like nausea and vomiting, leading to the development of thiethylperazine and other related compounds.

Comparative Analysis

Torecan is one of several phenothiazine antiemetics used in clinical practice. It has similar efficacy to other drugs in its class like perphenazine ( Trilafon) and prochlorperazine ( Compazine). Compared to newer antiemetics like ondansetron (Zofran) and aprepitant (Emend), phenothiazines tend to have a higher incidence of side effects, particularly extrapyramidal symptoms. However, they remain important treatment options for some patients.

Legal and Regulatory Status

Torecan (thiethylperazine) is a prescription drug that is FDA-approved for the treatment of nausea and vomiting. Generic versions of the drug are currently available in the United States following the discontinuation of the brand name product by Sanofi-Aventis. Thiethylperazine is a controlled substance in some countries due to its potential for abuse and dependence, although this is uncommon with therapeutic use.

Packaging and Labeling

Generic versions of thiethylperazine are supplied as tablets for oral use in strengths of 5 mg and 10 mg. The drug is also available as a solution for intramuscular injection. Package inserts provide important prescribing information, including indications, contraindications, warnings, precautions, adverse reactions, and dosing instructions. Patients should read the medication guide provided with their prescription and follow the instructions of their healthcare provider.

Bibliography and References

1. National Center for Biotechnology Information. ” Thiethylperazine.” PubChem Compound Database, U.S. National Library of Medicine.
2. Amos, J F, and P P Ellis. “A comparison of thiethylperazine and perphenazine in the management of nausea and vomiting.” Southern Medical Journal vol. 66,7 (1973): 761-3.
3. Marks, M R. ” Double-blind evaluation of thiethylperazine ( Torecan), perphenazine ( Trilafon), and a placebo in the control of emesis.” American Journal of Digestive Diseases vol. 6,7 (1961): 693-6.