Antipsychotic Drugs: Understanding How They Work and Their Side Effects

Types of Antipsychotic Medications

There are two primary categories of antipsychotic drugs - first-generation and second-generation. First-generation, or typical antipsychotics, were the first of these medications to be developed. They effectively control psychotic symptoms but frequently cause severe extrapyramidal side effects. Second-generation, or atypical antipsychotics, were created later on and provide comparable effectiveness with fewer extrapyramidal symptoms. Some common examples of first and second-generation antipsychotics include:

- First-generation: Haloperidol, chlorpromazine, thioridazine

- Second-generation: Risperidone, quetiapine, olanzapine, aripiprazole, ziprasidone

How Antipsychotics Work in the Brain

Antipsychotic Drugs are thought to work by blocking dopamine receptors in the brain, especially D2 receptors. Dopamine is a neurotransmitter strongly linked to psychosis. By blocking its receptors, these medications can reduce psychotic symptoms by modulating dopamine activity. However, their precise method of action is still not fully understood. They may also block serotonin, norepinephrine, acetylcholine, and histamine receptors to varying degrees. This multireceptor activity is likely key to controlling a wide range of psychotic symptoms.

Efficiency of Antipsychotics

According to clinical studies, antipsychotic drugs have been shown to significantly reduce symptoms of schizophrenia in 60-80% of patients. Response is often seen within 2-4 weeks of starting medication. Antipsychotics have also proven effective for treating acute manic or mixed episodes associated with bipolar disorder. They are first-line treatment options in psychosis and mania according to guidelines from the American Psychiatric Association. Maintenance antipsychotic treatment has also been found to lower the risk of relapse after an initial psychotic episode by about 70%.

Side Effects of Antipsychotic Medications

While antipsychotics provide substantial benefits, all medications carry a risk of adverse side effects that patients and their physicians must carefully consider. Side effects of these drugs can be divided into extrapyramidal (movement) symptoms and others. Some common side effects include:

Extrapyramidal side effects:
- Akathisia (inner restlessness)
- Parkinsonism (rigidity, tremors, slow movement)
- Tardive dyskinesia (involuntary muscle movements)