| GENERIC NAME: risperidone
BRAND NAME: Risperdal
DRUG CLASS AND MECHANISM: Risperidone is an antipsychotic
medication that works by interfering with the communication among nerves
in the brain. The nerves communicate with one another by producing and
releasing chemicals called neurotransmitters. The neurotransmitters attach
to receptors on other nearby nerves, and the attachment of the neurotransmitter
causes changes in the cells that have the receptor on them. Risperidone
blocks several of the receptors on nerves including dopamine type 2, serotonin
type 2, and alpha 2 adrenergic receptors and this blocks communication
among nerves. Risperidone is a relatively new antipsychotic medication
that probably has fewer side effects than many of the older medications.
PREPARATIONS: Tablets of 1, 2, 3, and 4 mg.
STORAGE: Tablets should be kept at room temperature,
15-30°C (59-86°F).
PRESCRIBED FOR: Risperidone is used for the treatment
of psychotic disorders, for example, schizophrenia. It also is used in
combination with lithium or valproate for the treatment of acute manic
or mixed episodes associated with bipolar I disorder.
DOSING: Risperidone usually is begun as two small doses
each day. The doses often are increased every few days or each week until
the optimal dose is found. Patients who are elderly or have kidney disease
may need lower doses since the kidneys, which are partially responsible
for removing risperidone from the blood, remove risperidone more slowly,
and this can lead to toxic levels of risperidone in the blood. Similarly,
patients with liver disease may need lower doses since the liver also
is partially responsible for removing risperidone.
DRUG INTERACTIONS: Risperidone may interfere with elimination
by the kidneys of clozapine (Clozaril), a different type of antipsychotic
medication, causing increased levels of clozapine in the blood. This could
increase the risk of side effects with clozapine.
PREGNANCY: There are no adequate studies of risperidone
in pregnant women. Some studies in animals suggest no important effects
on the fetus, whereas others suggest an ill-effect. Risperidone can be
used in pregnancy if the physician feels that the benefits outweigh the
potential but unknown risks.
NURSING MOTHERS: It is not known if risperidone is secreted
in breast milk.
SIDE EFFECTS: The most commonly noted side effects associated
with risperidone are extrapyramidal effects (sudden, often jerky, involuntary
motions of the head, neck, arms, body, or eyes), dizziness, hyperactivity,
tiredness, and nausea. Risperidone may cause a condition called orthostatic
hypotension during the early phase of treatment (the first week or two).
Patients who develop orthostatic hypotension have a drop in their blood
pressure when they rise from a lying position and may become dizzy.
Although there is no clear link between risperidone and diabetes, patients
should be tested during treatment for elevated blood-sugars. Additionally,
persons with risk factors for diabetes, including obesity or a family
history of diabetes, should have their fasting levels of blood sugar tested
before starting treatment and periodically throughout treatment to detect
the onset of diabetes. Any patient developing symptoms that suggest diabetes
during treatment should be tested for diabetes.
Caution! Before starting
to take this medicine, it is vital that you should consult your doctor!
Do not use it on your own initiative, without medical advice.
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