typical antipsychotic

2. Psychosis
Psychosis is a mental health problem involyes disorders in
thoughts, behavior, and emotions and characterized by
positive signs such as hallucinations (usually auditory),
delusions (fixed false believes commonly paranoid), and reality
distortion and negative signs as emotional dullness, low mood,
dementia, and social withdrawal.
Biochemical etiology of Psychosis:
Increased activity of D2- dopamine receptors and /or 5HT2-
serotonin receptors in the limbic system

3. Typical anti-psychotic drugs:
1. Phenothiazines: e.g. chlorpromazine.
2. Butyrophenones: e.g. haloperidol.
Mechanism of action:
They block D2-receptors in the mesolimbic pathway.
Pharmacokinetics:
_absorbed after oral administration
-They are highly bound to plasma proteins
-They are highly lipophilic.
-They are metabolized in the liver CYP450 -conjugation.
- half-lives are typically 20-40 hours allowing once daily
administration and tendency to accumulate in the body.

4. PHARMACOLOGICAL ACTIONS:
1
- CNS:
1) ANTIPSYCHOTIC ACTIONS:
TYPICAL →POSITIVE SYMPTOMS
2
) EXTRAPYRAMIDAL EFFECTS
• PARKINSONISM
• ACUTE DYSTONIA:MANAGED BY (PROCYCLIDINE).
• DYSKINESIA
3
) ANTIEMETIC EFFECTS:
CHLORPROMAZINE AS ONE OF THE TYPICAL ANTIPSYCHOTICS
INHIBIT D2 RECEPTORS IN CTZ.

5. 2- AUTONOMIC NERVOUS SYSTEM:
A) ANTICHOLINERGIC EFFECTS
B) Α-ADRENERGIC BLOCKING ACTIVITY: (ORTHOSTATIC
HYPOTENSION).
3- CVS:
PROLONGED QT INTERVAL (PARTICULARLY HALOPERIDOL).
4- ENDOCRINAL EFFECTS:
THE TYPICAL (OLDER) ANTIPSYCHOTICS AND ONLY
RISPERIDONE FROM THE ATYPICAL ANTIPSYCHOTICS INCREASE
PROLACTIN SECRETION..
5- ANTIHISTAMINIC EFFECT:
ANTAGONISTIC ACTIONS ON HISTAMINE RECEPTORS(H1)
WHICH MAY CONTRIBUTE TO THEIR SEDATIVE EFFECTS.

6. 6
. NEUROLEPTIC MALIGNANT SYNDROME:
IT IS A LIFE-THREATENING IDIOSYNCRATIC REACTION
TO ANTIPSYCHOTIC DRUGS CHARACTERIZED BY FEVER,
ALTERED MENTAL STATUS, MUSCLE RIGIDITY, AND
AUTONOMIC DYSFUNCTION. IT IS TREATED BY
COOLING AND DANTROLENE.
THERAPEUTIC USES:
• SCHIZOPHRENIA.
• BEHAVIORAL DISORDERS.
• ANTIEMETIC.