This article will investigate its uses, modes of action, side effects and precautions.
- What is aripiprazole?
- When is aripiprazole used?
- How does aripiprazole work?
- Side effects of aripiprazole
- Important warnings for aripiprazole
- Current research into aripiprazole
Here are some key points about aripiprazole. More detail and supporting information is in the main article.
- Aripiprazole is classed as an atypical antipsychotic.
- The drug is used for a number of conditions, most commonly schizophrenia.
- The exact mode of action for aripiprazole is still unclear.
- Aripiprazole can be useful in the treatment of certain autistic symptoms.
- Side effects can include aching limbs, dizziness and seizures.
- Aripiprazole was first approved for use in schizophrenia in 2002.
- In rare cases, it can cause neuroleptic malignant syndrome.
- Aripiprazole is being investigated for a potential role in the treatment of cocaine addiction.
What is aripiprazole?
Aripiprazole is an antipsychotic that works at a number of receptors and transporters.
Aripiprazole is classed as an atypical (second-generation) antipsychotic. It works at a large number of sites, including receptors and transporters.
Its chemical name is C23H27Cl2N3O2
The drug mediates its action by either blocking receptors (antagonist) or by binding to them and inducing an opposite response to receptor's normal role (inverse agonist).
Aripiprazole exerts its impact via various receptors including multiple subtypes of serotonin, dopamine, adrenergic, muscarinic acetylcholine and histamine receptors. It also works on serotonin, norepinephrine and dopamine transporter proteins.
The drug was first approved by the US Food and Drug Administration (FDA) for use in schizophrenia in 2002.
When is aripiprazole used?
Aripiprazole is used predominantly for the treatment of schizophrenia and bipolar disorder but can also be used as an add-on treatment for major depressive disorder, tic disorders, obsessive-compulsive disorders and irritability associated with autism.2
Schizophrenia was the first illness to be targeted by aripiprazole. The decision by the FDA to approve its use was based on clinical trials that showed aripiprazole's ability to lessen psychotic episodes and reduce relapses when compared to a placebo.
The current consensus of scientific opinion is that aripiprazole's effect is comparable to a number of other typical and atypical antipsychotics. It has fewer side effects than some, but more than others.3 Aripiprazole is considered a middle-range antipsychotic regarding its effectiveness.4
Aripiprazole can be effective in treating the acute manic episodes of bipolar disorder in adults, adolescents and children.
However, its effect is only useful for the manic phases with little or no effect on the depressive phases. For this reason, aripiprazole is often used in conjunction with mood stabilizers. This dual approach is effective, but increases the risk of movement disorders (extrapyramidal symptoms).5
Some patients are prescribed aripiprazole in conjunction with antidepressants, however, as above, this increases the risk of movement disorders; there is also an additional risk of weight gain.
Aripiprazole can be useful in reducing some aspects of autistic behavior. Studies show that it can reduce irritability, hyperactivity and repetitive movements (stereotypy) in autistic children and youths.
The side effects include weight gain, drooling, tremors and sleepiness.
There is some evidence that low doses of aripiprazole can yield positive results in obsessive-compulsive disorders (OCD) that are resistant to selective serotonin reuptake inhibitors (SSRI) alone.6
How does aripiprazole work?
As with other atypical antipsychotics, the exact method of action for aripiprazole is not known. The design of the drug was based on the dopamine hypothesis.
The dopamine hypothesis predicts that dopamine hyperactivity in the mesolimbic pathways of the brain (also known as reward pathways) causes delusions, hallucinations and disorganized thoughts.
Dopamine inactivity in the mesocortical pathways (involved in cognitive control, motivation and emotional response) and the prefrontal cortex (an area implicated in planning complex cognitive behavior and moderating social behavior) leads to an impairment in linguistic ability, an inability to experience pleasure and autism.7
Aripiprazole's effects at dopamine receptors are thought to decrease dopamine production and stabilize the dopamine system.8
Side effects of aripiprazole
As with any pharmacological intervention, there will be side effects. Aripiprazole has a range, from subtle to major:
Minor side effects
- Pain in the limbs or joints
- Increased production of saliva
- Weight gain and increased appetite
- Abdominal pain
- Dizzy spells
Aripiprazole could be dangerous if taken by elderly patients with dementia-related psychosis.
Major side effects
- Irregular heart beat
- Breathing difficulties
- Tightening of neck muscles and throat
- Swelling of the eyes, face, mouth, throat, hands, ankles, feet, lower legs
- Hives, rashes and general itching
- Chest pain
- Changes in vision
- Unusual movements
- Stiff muscles.
Important warnings for aripiprazole
These are some of the most recent important warnings to take into account before starting a course of aripiprazole:
Elderly people with dementia-related psychosis
Recent research has found an increased risk of death with use of aripiprazole in patients aged 77-88 with dementia-related psychosis.
The deaths were due to adverse events within the circulatory system in the brain (cerebrovascular).9
Neuroleptic malignant syndrome
There is a possibility that aripiprazole might induce neuroleptic malignant syndrome (NMS). NMS is a potentially life-threatening neurological disorder consisting of muscle rigidity, fever, delirium or coma and autonomic instability.10
People with depression
During clinical trials, a small number of depressed children, teenagers and young adults taking aripiprazole reported an increase in suicidal thoughts.
At this stage, the prevalence of this side effect in younger people is not known.
Current research into aripiprazole
As with any drug that acts at a variety of different sites, research into its full capabilities is ongoing. Below are two areas of current research.
Potential role in cocaine addiction
Aripiprazole is known to stabilize mesocorticolimbic dopamine activity. This pathway is implicated in addictive behavior. A study in rats showed that aripiprazole reduced cocaine-seeking behavior. As such, it has implications for use in the treatment of cocaine addicts in the future.11
Negative implications for methamphetamine addicts
On the other side of the coin, aripiprazole may be counter-productive as a treatment for methamphetamine addiction. It was found to increase methamphetamine's stimulant and euphoric effects. Aripiprazole also appeared to increase the desire for the drug.12
Immune cells are more active in the brains of people at risk of schizophrenia, as well as those already diagnosed with the disease, according to a study published in the American Journal of Psychiatry.
Antipsychotic medications are the most common treatment for individuals with schizophrenia, helping to relieve some of the debilitating symptoms caused by the disorder. But according to a new study, long-term use of these drugs may also negatively impact brain structure.