DESCRIPTION / DEFINITIONS: Risperdal® (risperidone) is a atypical antipsychotic. Risperdal is a drug prescribed for the acute and maintenance treatment of Schizophrenia and the short-term treatment of bipolar disease.
ADDICTION / DEPENDENCE: Half life and metabolism, Black Box Warning.
SIDE EFFECTS: Stroke, transient ischemic attack, fatalities, worsening of their depression, suicidal ideation and behavior (see list below).
WITHDRAWAL SYMPTOMS: Dizziness, hyperkinesias, somnolence, nausea (see list below).
TREATMENT: Medical detoxification.
DESCRIPTION / DEFINITIONS
Risperdal (risperidone) is prescribed for the treatment of schizophrenia. According to its label, “The mechanism of action of RISPERDAL® (risperidone), as with other drugs used to treat schizophrenia, is unknown. However, it has been proposed that the drug's therapeutic activity in schizophrenia is mediated through a combination of dopamine Type 2 (D2) and serotonin Type 2 (5HT2) receptor antagonism.”
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 Risperdal is 3 hours.
Risperdal is mainly metabolized through the P450 pathway in the liver and the enzyme primarily handling the metabolism is 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
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. Risperdal has a black box warning. Here is the warning.
WARNING: Increased Mortality in Elderly Patients with DementiaRelated 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. RISPERDAL® (risperidone) is not approved for the treatment of patients with Dementia-Related Psychosis.
The following information is taken from the Risperdal label:
Risperdal can be a very difficult drug to stop taking.
- emesis (vomiting)
- extrapyramidal symptoms
- muscle pain
- rhinorrhoea (runny nose)
Withdrawal from Risperdal 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 Risperdal in about seven days. Patients can withdraw from Risperdal on an outpatient basis but it will normally take at least four weeks.