Brexiprazole is a second generation antipsychotic . It was developed in the United States and began to be marketed there in 2015. It is used as an adjuvant treatment for patients with schizophrenia or major depressive disorder.
It is indicated for patients who have not responded well to treatments based solely on antidepressants. In this article we will know its characteristics, precautions to be taken, mechanism of action, uses and side effects.
Brexiprazole: an atypical antipsychotic
Brexiprazole is a second generation antipsychotic drug (atypical antipsychotic). Its hitherto unknown mechanism of action causes the amount of certain substances in the brain to be changed. It is known, however, that the mechanism is related to dopamine, serotonin and noradrenaline , the main neurotransmitters in the brain.
Typical and atypical antipsychotics
Compared to typical or first-generation antipsychotics, atypicals are more advanced and produce fewer side effects, as they interact with fewer neurotransmitters or substances.
Moreover, in the case of schizophrenia, they have the advantage of not only treating the positive symptoms of schizophrenia (hallucinations, disorganized language, delusions,…) (as the typical ones do), but also treating the negative symptoms of schizophrenia (abulia, emotional flattening, depression,…), although to a lesser extent. The typical antipsychotics, on the other hand, do not act on the negative symptoms.
Brexiprazole was discovered by the pharmaceutical company Otsuka Pharmaceutical Co. (Otsuka) and co-developed by Otsuka and Lundbeck. The Food and Drug Administration (FDA) approved it as an adjuvant treatment for adults with major depressive disorder and as a treatment for adult schizophrenia. It began to be marketed in 2015 in the USA.
This was because many of the adults with major depressive disorder (MDD) (specifically, 15 million in the United States) had a poor response to antidepressant monotherapy (that is, using only these drugs as treatment). Brexiprazole was developed to address this type of patient.
Mechanism of action
The mechanism of action of brexpiprazole in the treatment of major depressive disorder or schizophrenia is unknown. However, its mechanism of action is known to be related to a combination of partial agonist activity at the serotonin 5-HT1A and dopamine D2 receptors .
It also acts antagonistically on the 5-HT2A serotonin receptors. Brexiprazole also has a high affinity for these receptors, in addition to others, the alpha 1B/2C noradrenaline receptors. The fact that it has a high affinity means that it fits very well with them, i.e. its efficacy is high.
Brexiprazole is indicated to treat the symptoms of schizophrenia. It is also used as an antidepressant to treat depression , in cases where symptoms cannot be relieved by antidepressants alone.
How do you take it?
Brexpiprazole is taken orally in tablet or pill form . It is usually taken only once a day. It is recommended that it be taken at the same time every day.
If you miss a dose, take another one as soon as possible, but skip the missed dose if it is almost time for the next one. It is important never to take two doses at once.
The side effects associated with brexiprazole are headache, constipation, heartburn, tiredness, uncontrollable shaking of a body part, dizziness , feeling of instability and difficulty in maintaining balance.
There are other, less frequent but more serious side effects, which, if they occur, should be reported to the doctor immediately. Some of these effects are: hives, itching, swelling of different parts of the face or body (e.g. eyes, face, mouth, lips, tongue, throat, hands, feet, ankles or lower legs), difficulty breathing or swallowing, convulsions, difficulty breathing, sore throat, coughing, chills and other signs of infection, etc.
Brexiprazole is not indicated or approved to treat psychotic symptoms associated with dementia . It is also not suitable for people under 18 years of age.
On the other hand, it’s important to note that once brexiprazole treatment is started, some people have even expressed thoughts of suicide (and more so if they were using the drug for the first time).
That is why we must be alert to possible changes in the person’s mood, as well as to signs that lead us to think about self-policing or suicide.
As for pregnancy , it is known that taking antipsychotics in the last 3 months of pregnancy can cause breathing problems, feeding problems, or withdrawal symptoms in the newborn.
The efficacy of brexpiprazole was demonstrated in two 6-week placebo-controlled clinical trials , conducted in adult patients who met the DSM-IV-TR criteria for major depressive disorder (MDD).
Some of these patients also had symptoms of anxiety, and none of them had previously achieved an adequate response during 1 to 3 treatment attempts with antidepressant drugs. In addition, they also had not achieved an adequate response in a phase of simple antidepressant therapy that was blinded for 8 weeks.
- Maeda, K. et al. (2014)- Pharmacological Profile of Brexpiprazole (OPC-2471234712): a Novel Serotonin-Dopamine Activity Modulator. Poster presentation at the American Psychiatric Association annual meeting.
- Rush, J. et al. Acute and Longer-Term Outcomes in Depressed Outpatients Requiring One or Several Treatment Steps: A STAR-D Report.
- Stahl, S.M. (2002). Essential Psychopharmacology. Neuroscientific bases and clinical applications. Barcelona: Ariel.