Résumé de section

  • Neuroleptics (Antipsychotics)

    Introduction

    Neuroleptics, also known as antipsychotics, are a group of medications used to treat mental and psychiatric disorders, particularly those involving symptoms such as hallucinations, delusions, and cognitive disturbances. These drugs are essential tools in psychiatry, as they help control both acute and chronic symptoms of psychiatric disorders such as schizophrenia, bipolar disorder, and psychosis caused by other factors.

    In this lecture, we will discuss the definition of neuroleptics, their mechanism of action, classifications, indications, side effects, and how to prescribe them correctly. We will also review some common examples of these medications available in the Algerian market.

    Definition of Neuroleptics

    Neuroleptics are medications that work to suppress or reduce the negative symptoms associated with psychosis, such as hallucinations and delusions. These drugs are primarily used to treat psychiatric disorders that affect thinking and perception, such as schizophrenia and bipolar disorder.

    Neuroleptics work by affecting neurotransmitters in the brain, particularly dopamine, by reducing its activity in certain brain regions that are overactive in psychotic states.

    Mechanism of Action of Neuroleptics

    Neuroleptics primarily work by blocking dopamine receptors in the brain, especially D2 receptors. Dopamine is a neurotransmitter that plays a key role in regulating mood, behavior, and cognition. In psychotic states, there is an overactivity of dopamine in certain brain regions, leading to symptoms such as hallucinations and delusions.

    In addition to blocking dopamine receptors, some neuroleptics also affect other neurotransmitters, such as serotonin, which helps improve the negative symptoms of psychosis, such as social withdrawal and inability to express emotions.

    Classification of Neuroleptics

    Neuroleptics are classified into two main types:

    1. Typical Antipsychotics

    These drugs primarily block dopamine D2 receptors. They are effective in treating the positive symptoms of psychosis, such as hallucinations and delusions, but they may cause motor side effects such as tremors and stiffness.

    Examples of Typical Antipsychotics:

    • Haloperidol: Used to treat schizophrenia and other psychotic disorders.

    • Chlorpromazine: Used to treat schizophrenia and psychomotor agitation.

    2. Atypical Antipsychotics

    These drugs block both dopamine and serotonin receptors. They are more effective in treating the negative symptoms of psychosis and have fewer motor side effects compared to typical antipsychotics.

    Examples of Atypical Antipsychotics:

    • Risperidone: Used to treat schizophrenia and bipolar disorder.

    • Olanzapine: Used to treat schizophrenia and other psychotic disorders.

    Indications for Neuroleptics

    Neuroleptics are used to treat a wide range of psychiatric and mental disorders, including:

    1. Schizophrenia: Neuroleptics are the primary treatment for schizophrenia, as they help control both positive symptoms (such as hallucinations and delusions) and negative symptoms (such as social withdrawal).

    2. Bipolar Disorder: Neuroleptics are used to treat manic and depressive episodes associated with bipolar disorder.

    3. Psychosis Due to Other Causes: Such as psychosis caused by substance abuse or organic diseases.

    4. Severe Anxiety and Psychomotor Agitation: Some neuroleptics are used to calm patients experiencing severe agitation.

    Side Effects of Neuroleptics

    Despite their effectiveness in treating psychiatric disorders, neuroleptics can cause a range of side effects, which vary depending on the type of medication and the dosage used. Some of the most common side effects include:

    1. Motor Side Effects: Such as tremors, stiffness, and an inability to sit still (akathisia). These side effects are more common with typical antipsychotics.

    2. Weight Gain: Especially with atypical antipsychotics such as olanzapine and risperidone.

    3. Dry Mouth and Constipation: Due to the drugs' effects on the autonomic nervous system.

    4. Sleep Disturbances: Such as insomnia or excessive drowsiness.

    5. Menstrual Irregularities: Especially in women taking neuroleptics.

    6. Increased Risk of Diabetes: Due to weight gain and the drugs' effects on metabolism.

    Prescribing Neuroleptics

    When prescribing neuroleptics, doctors must consider several factors, including:

    1. Accurate Diagnosis: A precise diagnosis must be made before prescribing the medication, as some disorders may have similar symptoms but require different treatments.

    2. Appropriate Dosage: Treatment should start with low doses and gradually increase to minimize side effects.

    3. Duration of Treatment: Patients may need to take the medication for long periods, especially in cases of chronic schizophrenia.

    4. Monitoring Side Effects: Patients should be regularly monitored for any side effects that may arise from taking the medication.

    Examples of Neuroleptics in the Algerian Market

    In Algeria, several neuroleptics are available, including:

    1. Haloperidol: Sold under the brand name Haldol, it is used to treat schizophrenia and other psychotic disorders.

    2. Risperidone: Sold under the brand name Risperdal, it is used to treat schizophrenia and bipolar disorder.

    3. Olanzapine: Sold under the brand name Zyprexa, it is used to treat schizophrenia and other psychotic disorders.

    4. Chlorpromazine: Sold under the brand name Largactil, it is used to treat schizophrenia and psychomotor agitation.

    Conclusion

    Neuroleptics are essential medications for treating psychiatric disorders, particularly those involving psychotic symptoms. Despite their effectiveness, they can cause side effects that require careful monitoring by the prescribing physician. Doctors and mental health professionals must have a thorough understanding of how these drugs work, their classifications, and how to prescribe them correctly to ensure the best therapeutic outcomes for patients.

    Some References

    1. Rawal Muhammad Jameel Qasim, et al. (2006). Pharmaceutical Sciences. Amman: Dar Al-Thaqafa for Publishing and Distribution.

    2. Ali Ismail Abdel Rahman. (2006). Introduction to Psychopharmacology. Cairo: Dar Al-Yaqeen for Publishing and Distribution.

    3. Jerrold S. Meyer, Linda F. Quenzer. (2005). Psychopharmacology: Drugs, The Brain, and Behavior. Sinauer Associates, Inc. Publishers.

    4. Muse, M., & Moore, B. A. (Eds.). (2012). Handbook of Clinical Psychopharmacology for Psychologists. John Wiley & Sons