How Does Zyprexa Work
The exact
workings of Zyprexa are not fully known. Researchers
however do know that this antipsychotic drug works
by affecting several neurotransmitters in the
brain that are altered in people with schizophrenia
or bipolar disorder.
Zyprexa reduces the symptoms of schizophrenia
and bipolar disorder by blocking the various neurotransmitters
of serotonin and dopamine. Zyprexa blocks the
serotonin (5HT2A) receptor more potently than
the dopamine (D2) receptor.
Older antipsychotic drugs are difficult to use
as they produce side effects like weight gain,
fatigue, stiff body movement, and blurred vision.
Newer antipsychotics like Zyprexa do not cause
as much blurred vision, dryness of the mouth,
or stiff body movements.
They treat symptoms of psychosis, such as hallucinations
and delusions and help to increase concentration
and provide clearer thought. Zyprexa adjusts the
imbalance of chemicals in the brain, and helps
people to handle stress more effectively.
However, while Zyprexa is more effective than
other antipsychotic drugs, it also carries a greater
risk of causing extrapyramidal side effects.
Extrapyramidal side effects include slowing
of voluntary movement, expressionless face, rigidity
and tremor of arms and head, abnormal tension
of muscle tissues, and restlessness.
An oral tablet dose of 10 mg daily has been found
to be effective for treating most people with
schizophrenia. Often a single dose 10 mg Zyprexa
at bedtime has been an effective initial prescribing
dose in most patients. However, some patients
do require a higher dosage.
Warnings
Neuroleptic Maligant
Syndrome (NMS)
Neuroleptic Malignant Syndrome (NMS)
has been reported with the administration of antipsychotic
drugs like Zyprexa.
Symptoms Of NMS Include
Hyperpyrexia;
muscle rigidity; altered mental status and evidence
of autonomic instability i.e. irregular pulse
or blood pressure, tachycardia, diaphoresis and
cardiac dysrhythmia; creatinine phosphokinase;
myoglobinuria (rhabdomyolysis); and acute renal
failure. If any of these symptoms do occur, immediately
discontinue Zyprexa and contact your doctor.
Tardive Dyskinesia
Tardive Dyskinesia is a syndrome that is potentially
irreversible. Symptoms include; involuntary and
dyskinetic movements. Zyprexa should be prescribed
in such a way that it minimizes the risk of tardive
dyskinesia. If signs of tardive dyskinesia appear,
discontinuation of Zyprexa should be considered
and the need for continued treatment with this
drug should be reassessed periodically.
Precautions
Orthostatic Hypotension
Zyprexa can cause orthostatic hypotension
associated with dizziness, tachycardia in some
patients during initial treatment. Caution is
advised in patients with known cardiovascular
disease history, heart failure, cerebrovascular
disease, and conditions which would predispose
patients to hypotension.
Seizures
Zyprexa should be used cautiously in patients
with a history of seizures or convulsions, or
patients who have Alzheimer’s disease.
Liver Problems
Caution should be exercised in patients with signs
or symptoms of liver impairments. People with
pre-existing liver problems need to be careful
when taking Zyprexa.
Body Temperature
Regulation
Zyprexa
can make you sweat less and keep the body from
cooling off. Be careful not to get overheated
while you are exercising, or using a sauna or
in extremely hot weather.
Dysphagia
Esophageal dysmotility and aspiration
has also been associated with Zyprexa. Caution
is advised in patients at risk for aspiration
pneumonia.
Cognitive or Motor
Performance
Zyprexa has the potential to impair judgment;
thinking; and/or motor skills; caution is advised
if you operate hazardous machinery or drive.
Call your local doctor
right away if you have any of these side effects:
- Fast or irregular heartbeat
- Feeling as if you need to be moving constantly
- High fever, muscle stiffness
- Increased sweating, thirst, or trouble urinating
- Muscle spasms, twitching, or uncontrolled
tongue or jaw movement
- Severe muscle weakness, trouble standing
- Trouble swallowing
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