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CLOZAPINE (Systemic)
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Some commonly used brand names are:
In the U.S.—
Clozaril
In Canada—
Clozaril
Leponex
Generic name product may be available in the U.S.
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Category
Antipsychotic
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Description
Clozapine (KLOE-za-peen) is used to treat schizophrenia in
patients who have not been helped by or are unable to take
other medicines.
Clozapine is available only from pharmacies that agree to
participate with your doctor in a plan to monitor your blood
tests. You will need to have blood tests done every week for
at least 6 months. After that, your doctor will decide if
it is safe for you to have blood tests every other week. You
will receive enough clozapine to last until your next blood
test, but only if the results of your blood tests show that
it is safe for you to take this medicine. If any of your blood
tests are not normal, you may need to have blood tests more
often than every week until they return to normal.
Clozapine is available in the following dosage form:
Oral
Tablets (U.S. and Canada)
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Before Using This Medicine
In deciding to use a medicine, the risks of taking the medicine
must be weighed against the good it will do. This is a decision
you and your doctor will make. For clozapine, the following
should be considered:
Allergies—Tell your doctor if you have ever had any
unusual or allergic reaction to clozapine. Also tell your
health care professional if you are allergic to any other
substances, such as foods, preservatives, or dyes.
Pregnancy—Clozapine has not been studied in pregnant
women. However, clozapine has not been shown to cause birth
defects or other problems in animal studies.
Breast-feeding—Clozapine may pass into breast milk and
cause drowsiness, trouble in nursing, restlessness or irritability,
convulsions (seizures), or heart or blood vessel problems
in nursing babies.
Children—Studies on this medicine have been done only
in adult patients, and there is no specific information comparing
use of clozapine in children with use in other age groups.
Older adults—Many medicines have not been tested in
older people. Therefore, it may not be known whether they
work exactly the same way they do in younger adults. Clozapine
may be more likely to cause side effects in the elderly, including
dizziness and fainting, low blood pressure, and confusion
or excitement.
Other medicines—Although certain medicines should not
be used together at all, in other cases two different medicines
may be used together even if an interaction might occur. In
these cases, your doctor may want to change the dose, or other
precautions may be necessary. When you are taking clozapine,
it is especially important that your health care professional
know if you are taking any of the following:
Alcohol or
Central nervous system (CNS) depressants (medicines that cause
drowsiness) or
Tricyclic antidepressants (amitriptyline [e.g., Elavil], amoxapine
[e.g., Asendin], clomipramine [e.g., Anafranil], desipramine
[e.g., Pertofrane], doxepin [e.g., Sinequan], imipramine [e.g.,
Tofranil], nortriptyline [e.g., Aventyl], protriptyline [e.g.,
Vivactil], trimipramine [e.g., Surmontil])—Using these
medicines or alcohol with clozapine may cause increased drowsiness,
low blood pressure, or trouble in breathing
Amantadine (e.g., Symmetrel) or
Antihypertensives (high blood pressure medicine) or
Antipsychotics (medicine for mental illness) or
Bromocriptine (e.g., Parlodel) or
Certain eye drops used to treat glaucoma (carteolol [e.g.,
Ocupress], levobunolol [e.g., Betagan], metipranolol [e.g.,
OptiPranolol], timolol [e.g., Timoptic]) or
Diuretics (water pills) or
Levodopa (e.g., Dopar) or
Medicine for heart disease or
Nabilone (e.g., Cesamet) (with high doses) or
Narcotic pain medicine or
Pentamidine (e.g., Pentam) or
Pimozide (e.g., Orap) or
Promethazine (e.g., Phenergan) or
Trimeprazine (e.g., Temaril)—Using these medicines with
clozapine may cause low blood pressure, which can cause dizziness
or fainting
Amphotericin B by injection (e.g., Fungizone) or
Antineoplastics (cancer medicine) or
Antithyroid agents (medicine for overactive thyroid) or
Azathioprine (e.g., Imuran) or
Chlorambucil (e.g., Leukeran) or
Chloramphenicol (e.g., Chloromycetin) or
Colchicine or
Cyclophosphamide (e.g., Cytoxan) or
Flucytosine (e.g., Ancobon) or
Ganciclovir (e.g., Cytovene) or
Interferon (e.g., Intron A, Roferon-A) or
Mercaptopurine (e.g., Purinethol) or
Methotrexate (e.g., Mexate) or
Plicamycin (e.g., Mithracin) or
Zidovudine (e.g., AZT, Retrovir)—Taking clozapine with
any of these medicines may increase the chance that very serious
blood problems will occur
Lithium—Using clozapine with lithium may increase the
chance that convulsions (seizures), confusion or problems
with movement will occur
Selective serotonin reuptake inhibitors (fluoxetine [e.g.,
Prozac], fluvoxamine [e.g., Luvox], paroxetine [e.g., Paxil],
sertraline [e.g., Zoloft])—These medicines can increase
the blood levels of clozapine, which increases the chance
that unwanted effects will occur
Other medical problems—The presence of other medical
problems may affect the use of clozapine. Make sure you tell
your doctor if you have any other medical problems, especially:
Blood diseases or
Enlarged prostate or difficult urination or
Gastrointestinal problems or
Glaucoma, narrow angle or
Heart or blood vessel problems—Clozapine may make these
conditions worse
Epilepsy or other seizure disorder—Clozapine may increase
the chance that seizures will occur
Kidney or liver disease—Higher blood levels of clozapine
may occur, increasing the chance that unwanted effects will
occur
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Proper Use of This Medicine
Take this medicine exactly as directed . Do not take more
of this medicine and do not take it more often than your doctor
ordered. Do not miss any doses.
This medicine has been prescribed for your current medical
problem only . It must not be given to other people or used
for other problems unless you are directed to do so by your
doctor.
Dosing—The dose of clozapine will be different for different
patients. Follow your doctor's orders or the directions on
the label . The following information includes only the average
doses of clozapine. If your dose is different, do not change
it unless your doctor tells you to do so.
The number of tablets that you take depends on the strength
of the medicine. Also, the number of doses you take each day,
the time allowed between doses, and the length of time you
take the medicine depend on your special needs .
For oral dosage form (tablets):
For schizophrenia:
Adults—At first, 12.5 milligrams (mg) (one half of a
25-mg tablet) once or twice a day. Your doctor may increase
your dose as needed. However, the dose usually is not more
than 900 mg a day.
Children younger than 16 years of age—Use and dose must
be determined by your doctor.
Missed dose—If you miss a dose of this medicine, take
it as soon as possible. However, if it is almost time for
your next dose, skip the missed dose and go back to your regular
dosing schedule. Do not double doses.
If you miss 2 or more days of clozapine doses, talk to your
doctor before you start taking it again. You may need to restart
this medicine at a lower dose than you were taking before.
Storage—To store this medicine:
Keep out of the reach of children.
Store away from heat and direct light.
Do not store in the bathroom, near the kitchen sink, or in
other damp places. Heat or moisture may cause the medicine
to break down.
Do not keep outdated medicine or medicine no longer needed.
Be sure that any discarded medicine is out of the reach of
children.
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Precautions While Using This Medicine
It is important that you have your blood tests done when they
are scheduled, and that your doctor check your progress at
regular visits . Clozapine can cause some very serious blood
problems that you may not be able to feel or see. The pharmacy
will give you this medicine only if your blood tests show
that it is safe for you to take clozapine. Also, your doctor
will make sure the medicine is working properly and change
the dosage if needed.
If you do not take clozapine for 2 or more days, talk to
your doctor about what to do . You may need to take a lower
dose when you first start taking this medicine again.
If you have been using this medicine regularly, do not stop
taking it without first checking with your doctor. Your doctor
may want you to reduce gradually the amount you are taking
before stopping completely. This is to help prevent the illness
from suddenly returning.
This medicine will add to the effects of alcohol and other
CNS depressants (medicines that slow down the nervous system,
possibly causing drowsiness). Some examples of CNS depressants
are antihistamines or medicine for hay fever, other allergies,
or colds; sedatives, tranquilizers, or sleeping medicine;
prescription pain medicine or narcotics; barbiturates; medicine
for seizures; muscle relaxants; or anesthetics, including
some dental anesthetics. Check with your doctor before taking
any of the above while you are using this medicine .
Contact your doctor as soon as possible if you develop unusual
tiredness or weakness, fever, sore throat, or other symptoms
of infection. These can be symptoms of a very serious blood
problem.
Contact your doctor as soon as possible if you have chest
pain or discomfort, a fast heartbeat, trouble breathing, or
fever and chills. These can be symptoms of a very serious
problem with your heart.
Clozapine may cause drowsiness, blurred vision or convulsions
(seizures). Do not drive, climb, swim, operate machines or
do anything else that could be dangerous while you are taking
this medicine.
Dizziness, lightheadedness, or fainting may occur, especially
when you get up from a lying or sitting position. Getting
up slowly may help. If this problem continues or gets worse,
check with your doctor.
In some patients, clozapine may cause increased watering
of the mouth. Other patients, however, may get dryness of
the mouth. For temporary relief of mouth dryness, use sugarless
gum or candy, melt bits of ice in your mouth, or use a saliva
substitute. However, if your mouth continues to feel dry for
more than 2 weeks, check with your medical doctor or dentist.
Continuing dryness of the mouth may increase the chance of
dental disease, including tooth decay, gum disease, and fungus
infections.
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Side Effects of This Medicine
Along with its needed effects, a medicine may cause some unwanted
effects. Some side effects may not have signs or symptoms
that you can see or feel. Clozapine can cause some very serious
blood problems. Your doctor will watch for these by doing
blood tests every week or two for as long as you are taking
clozapine and for 4 weeks after you stop taking it. Although
not all of these side effects may occur, if they do occur
they may need medical attention.
Check with your doctor immediately if any of the following
side effects occur:
More common
Fast or irregular heartbeat; fever; low blood pressure
Less common
High blood pressure (severe or continuing headache)
Rare
Chest pain or discomfort; chills; convulsions (seizures);
cough; difficult or fast breathing or sudden shortness of
breath; fainting; increased sweating; loss of bladder control;
muscle stiffness (severe); sore throat; sores, ulcers, or
white spots on lips or in mouth; swelling or pain in leg;
trouble breathing; unusual bleeding or bruising; unusual tiredness
or weakness; unusually pale skin
Check with your doctor as soon as possible if any of the
following side effects occur:
More common
Dizziness, especially when getting up from a lying or sitting
position
Less common
Blurred vision; confusion; restlessness or need to keep moving;
unusual anxiety, nervousness, or irritability
Rare
Absence of or decrease in movement; decreased sexual ability;
high blood sugar (increased appetite, increased thirst, increased
urination, weakness); lip smacking or puckering; liver problems
(dark urine, decreased appetite, nausea, vomiting, yellow
eyes or skin); mental depression; puffing of cheeks; rapid
or worm-like movements of tongue; trembling or shaking; trouble
in sleeping; trouble in urinating; uncontrolled chewing movements;
uncontrolled movements of arms and legs
Symptoms of overdose
Convulsions (seizures); dizziness or fainting; drowsiness
(severe) or coma; fast, slow, or irregular heartbeat; hallucinations
(seeing, hearing, or feeling things that are not there); increased
watering of mouth (severe); slow, irregular, or troubled breathing;
unusual excitement, nervousness, or restlessness
Other side effects may occur that usually do not need medical
attention. These side effects may go away during treatment
as your body adjusts to the medicine. However, check with
your doctor if any of the following side effects continue
or are bothersome:
More common
Constipation; dizziness or lightheadedness (mild); drowsiness;
headache (mild); increased watering of mouth; nausea or vomiting;
unusual weight gain
Less common
Abdominal discomfort or heartburn; dryness of mouth
Other side effects not listed above may also occur in some
patients. If you notice any other effects, check with your
doctor.
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