Drugs which are used for schizophrenic patient, which is a psychotic disorder and showed classical symptoms of delusion and hallucinations.
These drugs are also known as
Anti-schizophrenic drugs
Anti-delusional drugs
Anti-hallucination drugs
Major tranquillizer drugs
Dopamine antagonist (these drugs suppress the Level of dopamine)
Dopamine blocker drugs
D2 receptor blocker drugs
These drugs improves the thought process and behaviour of client with psychotic symptoms.
Indication
Psychotic disorders like schizophrenia
Delirium
Dementia
Mania
Depression
Paranoid disorders
Mechanism of action
The exact mechanism of these drugs is unknown
- It thought to block post-synaptic dopamine receptor in the basal ganglia, hypothalamus, brain stem or medulla oblongata, so level of dopamine decrease in post-synaptic neurons.
- Typical anti-psychotic drugs also block the Chemoreceptors Trigger Zone (CTZ, a zone in the medulla that is sensitive to certain chemical stimuli, so may produce nausea) and vomiting center in brain so also producing antiemetic effect.
Classification
Anti-psychotic drugs mainly divided into two following categories :
1. 1st generation anti-psychotic drugs
- Also called typical anti-psychotic drugs or traditional anti-psychotic drugs.
- These are more effective in positive symptoms of schizophrenia like delusion, hallucinations and aggression.
- some examples of typical anti-psychotic drugs are as follows :
C – Chlorpromazine (1st anti-psychotic drug discovered in 1950s, causes side effect – pigmentation on cornea)
H – Haloperidol (post potent drug, cause heights EPS)
T – Thioridazine
F – Fluopherazine
2. 2nd generation anti-psychotic drugs
- Also known as Atypical or novel anti-psychotic drugs.
- These are more effective in negative symptoms of schizophrenia like apathy, anhedonia etc.
- some examples of atypical anti-psychotic drugs are as follows :
C – Clozapine (it cause minimum EPS and highest / maximum sedation effect, may cause agranulocytosis, also it is the 1st atypical anti-psychotic drug).
O – Olanzapine
R – Risperidone
Z – Ziprasidone
A – Aripiprazole
Q – Quetiapine
Side effects of anti-psychotic drugs
Some common side effects of anti-psychotic drugs are given below :
Dry mouth, Orthostatic hypotension, palpitation, tachycardia, blurred vision, urinary retention, constipation, photosensitivity, pruritus, gynaecomastia, lactation.
Extrapyramidal symptoms :-
Extrapyramidal symptoms (EPS) are a group of movement disorders that can occur as side effects of antipsychotic drugs. These symptoms are caused by the drugs’ effects on the dopamine system in the brain.
- Pseudo-parkinson – 40%
It is the most earliest EPS
It occurs due to decreased level dopamine in body.
It can be reversible.
A group of symptoms that resemble Parkinson’s disease, including tremors, rigidity, slow movement, mask like face, shuffling gait and drooling of saliva are seen.
Drug of choice is Levodopa - Akasthesia – 50%
This is the most common EPS (found in 50% cases)
It can be reversible.
Also referred as ‘walkie-talkie’
Feeling of restlessness and inability to sit still is seen in Akasthesia.
Drug of choice are beta-blockers. - Dystonia – 6%
It is the earliest EPS, Occurs due to increased acetylcholine (maintains muscle tone in the body) level in body. It can be reversible.
Involuntary contraction of the muscles of face, neck, or eyes are seen. Like neck and eyes turn one side look upward (Muscle tone increases in dystonia).
Drug of choice are anticholinergics, example – Benzotropine. - Tardive dyskinesia – 3%
It is a very rare and late EPS, can occur as a side effect of long-term use of anti-psychotics and is characterised by Involuntary movements of the face and body, such as lip smacking or tongue protrusion, that can become permanent if not recognized and treated early.
Drug of choice is Valbenazine (works by blocking the reuptake of dopamine, a neurotransmitter that is involved in movement control, in the brain).
NOTE :- EPS are minimal into atypical antipsychotic drugs. EPS can be distressing and affect a person’s quality of life. If the patient experience any of these symptoms while taking medication, it is important to speak with the doctor or healthcare provider right away. They may adjust the medication doses or recommend additional treatment options to manage these symptoms.
Complication of taking anti-psychotic drugs is
Neuroleptic malignant syndrome (NMS) is a rare but potentially life-threatening medical emergency that can occur as a side effect of certain medications, particularly antipsychotic medications. It occurs at the initiation of therapy, after changed from one medicine to another. NMS is characterized by a combination of symptoms that affect the nervous system, muscles, and vital organs.
Symptoms of NMS
High fever
Muscle rigidity
Confusion
Altered sensorium (classical symptom of EPS)
Rapid heartbeat
High or low blood pressure
Sweating, and
Respiratory distress.
In severe cases, NMS can cause organ failure, seizures, and coma.
Cause of NMS
The exact cause of NMS is not fully understood, but it is thought to be related to the drugs’ effects on the dopamine system in the brain. Certain factors, such as high doses of medication, rapid dose increases, and dehydration, can increase the risk of developing NMS.
Management of NMS
- Notify the HCP
- Monitor vital signs
- Initiate safety and seizure precautions
- Monitor level of consciousness
- Administer anti-pyretic.
- Monitor LFT and KFT
- Discontinuing the medication that is causing the symptoms and providing supportive care, such as intravenous fluids, electrolyte replacement, and medications to control muscle rigidity. In severe cases, hospitalization and intensive care may be necessary.
Intervention of EPS
- Inform that a full therapeutic effect of the medicine may not be evident for 3 to 6 weeks after initiation of the therapy. However, on observation therapeutic response may be apparent after 7 to 10 days.
- Inform that some medicines may cause a harmless changes in urine colour to pinkish or radish brown.
- Instruct the patient to avoid contact with sunlight.
- Avoid alcohol use.
- Instruct the patient to change positions slowly to avoid Orthostatic hypotension.
- Monitor urine output and blood glucose level.
- Monitor hepatotoxicity.
Clozapine
Atypical anti-psychotic drug also known as reserve drug (is used when the patient become intolerant from all antipsychotic medicines).
Clozapine cause minimum EPS.
Drug of choice in – Treatment resistant schizophrenia.
Side affects of clozapine
Agranulocytosis (most significant), a potentially life-threatening condition in which the body produces an abnormally low number of granulocytes, a type of white blood cell that helps fight off infections. For this reason, patients taking clozapine must have their WBC counts monitored (before and 1 week after starting of clozapine) & regularly to detect any changes.
Other side effects of clozapine can include weight gain, excessive salivation, maximum sedation.
Contraindication
Contraindication in patient who are on bone marrow suppressant treatment. Example – Carbamazepine (mood stabiliser drug causes bone marrow depression).
NOTE :- Despite its potential risks, clozapine can be an effective treatment for individuals with treatment-resistant schizophrenia and other psychotic disorders. It is important to work closely with a healthcare provider to monitor for any potential side effects and to manage symptoms effectively.
Miscellaneous :
Antipsychotic drugs which causes :
- EPS –
Minimum – 1st clozapine, 2nd thioridazine
Maximum – Haloperidol - Endocrine gland side effects –
Minimum – Aripiprazole
Maximum – Haloperidol - Sedation –
Minimum – Aripiprazole
Maximum – Clozapine (1st Atypical antipsychotic drug) - Pigment deposition in eyes
(a) Chlorpromazine – deposition in cornea (reversible)
(b) Thioridazine – deposition at ratine (irreversible). Also is the the cause for blindness. This drug also causes lack of libido. - Longest acting antipsychotic drug – (a)Penfluoride and (b)Fluphenazine