Risperidone is one of the drugs of choice for the treatment of schizophrenia and psychoses. Let’s take a look at how it works, as well as its effects.
Risperidone is an atypical antipsychotic or neuroleptic. It was introduced to the market in 1993. It treats both the positive and negative symptoms of schizophrenia.
Compared with other drugs in its group, risperidone causes few adverse reactions. More particularly, it causes few extrapyramidal side effects. In fact, in the long term, risperidone improves symptoms caused by other typical neuroleptics.
The uses of risperidone
According to the patient information sheet, risperidone is suitable for the following disorders:
- Manic episodes associated with bipolar disorder.
- Persistent aggression in patients with Alzheimer’s that doesn’t respond to other treatments. However, risperidone should only be used as a short-term treatment (less than six weeks).
- Persistent aggression in children from the age of five. Also, teens with behavioral disorders and intellectual disabilities. Treatment with risperidone should be accompanied by other measures. Nevertheless, it shouldn’t be used for longer than six weeks.
Mechanism of action
The mechanism of action of risperidone is complex. It acts as a selective monoaminergic antagonist on different types of receptors:
- Serotonin 5-HT2.
- Dopamine D2.
It also has an affinity for alpha-1 adrenergic receptors. Furthermore, it binds to the H1 receptors of histamine and alpha-2-adrenergic.
Therefore, its mechanism of action is a combination of the antagonistic effects on these receptors. In fact, in general terms, the hyperactivity of the dopaminergic pathway is considered to particularly contribute to the symptoms of schizophrenia. For this reason, the blocking of D2 receptors by risperidone deals with them.
Serotonergic pathways also influence schizophrenia. Risperidone, with its balanced serotonin-dopamine antagonism, controls the symptoms of schizophrenia. In addition, its antagonistic effect on serotonin counteracts the effects of dopamine. This reduces extrapyramidal symptoms.
The side effects of risperidone
As we mentioned above, the side effects associated with risperidone are lower than those linked to the classic antipsychotic drugs. For example, haloperidol. Especially noteworthy is the decrease in extrapyramidal symptoms. These symptoms are more prevalent with the use of traditional drugs.
One of the main side effects of risperidone is hypotension. It’s more marked at the beginning of treatment. It’s also more common in elderly and weaker patients. In addition, some patients treated with it experience neuroleptic malignant syndrome.
The most common side effects of this drug are:
- Drowsiness and decreased attention.
- Parkinsonism. This includes symptoms like slow movements, muscle stiffness, tremor at rest, or loss of facial expression.
However, other side effects may also occur. These include:
- Weight gain.
- Abdominal discomfort.
- Blurred vision.
- Urinary incontinence.
- Muscle spasms.
Risperidone is an extremely useful drug for the treatment of schizophrenia. This is because it selectively blocks the receptors involved in psychotic processes. Furthermore, the reduction of adverse extrapyramidal effects makes it one of the first drugs of choice for the treatment of this disorder.
However, as with any pharmacological treatment, patients should always follow their doctor’s instructions. Furthermore, they shouldn’t modify their dose without consulting them. Finally, they should discuss any adverse side effects with their doctor.
Schizophrenia’s Positive and Negative Symptoms