Neuroleptics and anti-psychotics

Question 1

Classification of the neuroleptic drugs?, what is their purpose ?

Answer 1

The neuroleptic drugs aka “anti-psychotic” drugs are used to treat and manage “psychiatric disorders”. Theres first generation (typical/classic) neuroleptics and theres second generation (atypical/newer) neuroleptics.

1. Atypical/classic neuroleptics :
   - Phenothiazine derivatives (Chlorazin 25mg and Thioridazin 5,10 and 50mg).

• Butyrophenone derivatives (Droperidol 0.25% 10ml Haloperidol tab-1.5mg/amp 0.5%)
• Thioxanthene derivatives (e.g: Fluanxol tab - 0.5/1.0 mg and Fluanxol depot amp. 2% 1ml).
  2. Typical/Newer neuroleptics ( Leponex 25,50 and 100mg)

Question 2

MOA of typical neuroleptics?

Answer 2

1. Blockage of dopamine receptors, blocking the action of dopamine.
2. Blockage of muscarnic receptors, having an atropine effect : reduced HR, urinary retention and blurred vision.
3. Blocking of adrenoreceptor type a1 : Vasodilation and orthostatic hypotension.
4. Blockage of histamine type 1 receptor : sedation/drowsiness.
5. Blockage of serotonin 5-HT2 receptor, desirable effect on anti-psychosis.

Question 3

MOA of Atypical neuroleptics?

Answer 3

1. Blockage of 5-HT2 receptors

2. Blockage of Dopamine receptors.

Question 4

Pharmacokinetics of the neuroleptic drugs? (its simple)

Answer 4

Good oral absorption, BBB/BPB penetration, liver metabolism and excretion in urine.

Question 5

Therapeutic uses of the neuroleptic drugs?

Answer 5

1. Treatment of schizophrenia (caused by excessive dopamine), which causes hallucinations, aggression and social exclusion.
2. Treatment of disturbed behaviour patients with Alzheimers disease.
3. Neuroleptics induce “psychotic depression” which reduces irrational behaviour, agitation and aggressiveness.

Question 6

What are the contraindications of the neuroleptic drugs?

Answer 6

1. Previous neuroleptic malignant syndrome. (life-threatening reaction associated with neuroleptic drug use).
2. Parkinsonism in the patient.
3. Possible severe reaction in dementia patients, which may cause death.

Question 7

ADR’s of neuroleptic drugs

Answer 7

1. Behavioural effects (drug induced alkensia/loss of control of voluntary movements).
2. Weight gain and hyperglycemia.
3. Neurological side effects (extrapyramidal reactions “akathisia” which is restlessness and also “typical parkinson syndrome”
4. Neuroleptic malignant syndrome

Question 8

What are the alternative drug interaction of these neuroleptic aka anti-psychotic drugs?

Answer 8

1. Risk of arrhythmia when a antipsychotic drug is combined with other drugs that affect rhythm or drugs that increase the concentration of the antipsychotic (eg azole antifungal drugs)
2. Rarely, antipsychotics can reduce white cell and red cell count; concomitant use with other drugs that interfere with bone-marrow function (myelo-suppressants) might increase the risk.
3. Co- administration of neuroleptics with drugs that are sedatives (eg. alcohol) or
   which reduces blood pressure (eg ACE inhibitor) can increase the
   potential for sedation or increase hypotensive effects.