ZYPREXA
DESCRIPTION / DEFINITIONS: Zyprexa® (olanzapine) is a atypical antipsychotic. Zyprexa is a drug prescribed for the treatment of schizophrenia and the treatment of bipolar depression and mania.
ADDICTION / DEPENDENCE: Half life and metabolism, Black Box Warning.
SIDE EFFECTS: Death, hostility, diabetes, panic attacks, paralysis (see list below).
WITHDRAWAL SYMPTOMS: Insomnia, symptoms of schizophrenia (such as hallucinations or delusions), bipolar disorder symptoms (such as mania or depression).
TREATMENT: Medical detoxification.
DESCRIPTION / DEFINITIONS
Zyprexa (olanzapine) is prescribed for the treatment of schizophrenia, bipolar depression and mania. According to its label, “The mechanism of action of olanzapine, as with other drugs having efficacy in schizophrenia, is unknown. However, it has been proposed that this drug’s efficacy in schizophrenia is mediated through a combination of dopamine and serotonin type 2 (5HT2) antagonism. The mechanism of action of olanzapine in the treatment of acute manic episodes associated with Bipolar I Disorder is unknown.”
ADDICTION / DEPENDENCE
HALF LIFE AND METABOLISM
The biological half life of a substance is the time it takes for a drug to lose half of its pharmacologic activity. This is significant because it affects how soon withdrawal symptoms may appear.
The half life of Zyprexa is between 21 and 54 hours.
Zyprexa is mainly metabolized through the P450 pathway in the liver and the enzymes primarily handling the metabolism is CYP1A2 and CYP2D6.
The CYP enzymes are the major enzymes involved in drug metabolism, and since many drugs may increase or decrease the activity of various CYP isozymes, this is a major source of adverse drug interactions, since changes in CYP enzyme activity may affect the metabolism and clearance of various drugs. For example, if one drug inhibits the CYP-mediated metabolism of another drug, the second drug may accumulate within the body to toxic levels, possibly causing an overdose.
BLACK BOX WARNING
The Food and Drug Administration (FDA) has decided that some drugs pose very serious risks and have required these drugs have what is called a black box warning. Zyprexa has a black box warning. Here is the warning.
WARNING
Increased Mortality in Elderly Patients with Dementia–Related Psychosis — Elderly patients with dementia–related psychosis treated with atypical antipsychotic drugs are at an increased risk of death compared to placebo. Analyses of seventeen placebo–controlled trials (modal duration of 10 weeks) in these patients revealed a risk of death in the drug–treated patients of between 1.6 to 1.7 times that seen in placebo–treated patients. Over the course of a typical 10–week controlled trial, the rate of death in drug–treated patients was about 4.5%, compared to a rate of about 2.6% in the placebo group. Although the causes of death were varied, most of the deaths appeared to be either cardiovascular (e.g., heart failure, sudden death) or infectious (e.g., pneumonia) in nature. ZYPREXA (olanzapine) is not approved for the treatment of patients with dementia–related psychosis (see
WARNINGS).
SIDE EFFECTS
The following information is taken from the Seroquel label:
WITHDRAWAL SYMPTOMS
Zyprexa can be a very difficult drug to stop taking.
- agitation
- anorexia
- anxiety
- bipolar disorder symptoms
- diarrhea
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- emesis (vomiting)
- insomnia
- itching
- muscle pain
- nausea
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- restlessness
- rhinorrhoea (runny nose)
- sweating
- symptoms of schizophrenia
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TREATMENT
Withdrawal from Zyprexa should only be done under the care of a health practitioner. The safest way is to withdraw at an inpatient medical detox facility. At an inpatient medical detox facility with a protocol that includes hydration, vitamins and supplements, most patients can safely stop taking Zyprexa in about seven days. Patients can withdraw from Zyprexa on an outpatient basis but it will normally take at least four weeks.
