Brand name:

Serentil

Generic name: Mesoridazine besylate

Why is Serentil prescribed?

Serentil is prescribed to treat schizophrenia, the crippling psychological disorder that causes its victims to lose touch with reality, often triggering hallucinations, delusions, and disorganized thought. Because of its dangerous side effects, this medication is recommended only after at least two other drugs have failed to provide relief.

Most important fact about Serentil

Serentil may cause dangerous and even fatal cardiac irregularities by prolonging a part of the heartbeat known as the QT interval. The likelihood of such irregularities increases when Serentil is combined with other medications known to prolong the QT interval, including certain heart medications. Never combine these drugs with Serentil, and check with your doctor before taking any other new medications.

Symptoms of a possible heart irregularity include palpitations, dizziness, and fainting. Call your doctor immediately if you experience any of these symptoms.

How should you take Serentil?

Take Serentil exactly as directed by your doctor. If you are taking Serentil in a liquid concentrate form, you can dilute it with distilled water, orange juice, or grape juice just before swallowing it.

If Serentil is given by injection, you should remain lying down for at least one-half hour after the injection.

• If you miss a dose...
  Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Do not take 2 doses at once.

• Storage instructions...
  Store at room temperature in a tightly closed container. Protect from light.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe to continue taking Serentil. Side effects generally occur when high doses are given early in treatment.

• Side effects may include:
  Blurred vision, drowsiness, dry mouth, impotence, incontinence, low blood pressure, nausea, rash, muscle rigidity, slowed heartbeat, tremor, vomiting

Why should Serentil not be prescribed?

You should not take Serentil if you have a history of heartbeat irregularities, or you are taking other medications that may cause an irregular heartbeat (see "Most important fact about this drug"). Serentil should not be combined with other substances that slow the nervous system, such as alcohol, barbiturates (sleep aids), and narcotics (painkillers), nor should it be given to anyone in a comatose state. People who have shown a hypersensitivity to Serentil cannot take this drug.

Special warnings about Serentil

Before using Serentil, tell your doctor if you have a history of heart problems. The doctor will perform tests to check the health of your heart before prescribing this medication.

Serentil can cause tardive dyskinesia, a condition marked by involuntary muscle spasms and twitches in the face and body, including chewing movements, puckering, puffing the cheeks, and sticking out the tongue. This condition may be permanent and appears to be most common among older adults, especially older women. Ask your doctor for more information about this possible risk.

Drugs such as Serentil can cause a potentially fatal condition called neuroleptic malignant syndrome (NMS). Symptoms include high fever, rigid muscles, irregular pulse or blood pressure, rapid heartbeat, excessive perspiration, and changes in heart rhythm. If you have these symptoms, contact your doctor immediately. Serentil therapy should be discontinued.

This type of drug can cause vision problems. Tell your doctor if you have a change in your vision while taking this medication.

Serentil may impair your ability to drive a car or operate machinery. Do not participate in any activities that require full alertness until you are sure of your reaction to this drug.

Serentil should be used with caution if you have ever had breast cancer. The drug stimulates production of a hormone that promotes the growth of certain types of tumors.

Serentil may cause a condition called agranulocytosis, a dangerous drop in the number of certain kinds of white blood cells. Symptoms include fever, lethargy, sore throat, and weakness.

Possible food and drug interactions when taking Serentil

Remember that Serentil must never be combined with alcohol, barbiturates, or narcotics. It's also best to avoid combining it with other drugs prescribed for schizophrenia, depression, or anxiety, or with the spasm-quelling drug atropine. Be careful, too, to avoid exposure to phosphorus insecticides.

Special information if you are pregnant or breastfeeding

The effects of Serentil during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, tell your doctor immediately. Pregnant women should use Serentil only if clearly needed.

It is not known whether Serentil appears in breast milk. Check with your doctor before deciding to breastfeed.

Recommended dosage for Serentil

Your doctor will tailor the dose of Serentil to your needs. Once your symptoms improve, the doctor will gradually reduce the dosage to the lowest effective dose.

ADULTS

Tablets and Oral Solution

The usual starting dose of Serentil tablets or oral solution is 50 milligrams taken 3 times daily. Over the long term, the usual daily dose ranges from 100 to 400 milligrams per day.

CHILDREN

The safety and effectiveness of Serentil in children have not been established.

Overdosage

An overdose of Serentil can be fatal. If you suspect an overdose, seek medical attention immediately.

• Symptoms of Serentil overdose may include:
  Absence of reflexes, agitation, blurred vision, coma, confusion, convulsions, difficulty breathing, disorientation, drowsiness, dry mouth, enlarged pupils, heartbeat irregularities, heart failure or arrest, high temperature, nasal congestion, overactive reflexes, rigid muscles, stupor, swollen throat, throat spasms, vomiting