Choice of antipsychotic drugs

Question 1

There is no first-line antipsychotic drug which is suitable for all patients. discuss how a decision is made regarding which drug is suitable for each individual

Answer 1

Influenced by the patient’s medication history, the degree of sedation required and consideration of individual patient factors such as risk of extrapyramidal side-effects, weight gain, impaired glucose tolerance, QT-interval prolongation etc.

Question 2

which generation of drugs might be better at treating negative symptoms of schizophrenia?

( Apathy absent, blunted or incongruous emotional responses reductions in speech social withdrawal)

Answer 2

Second generation antipsychotic drugs e.g. (Aripiprazole, clozapine, olanzapine, quetiapine and risperidone)

Question 3

Antipsychotic drugs that cause extrapyramidal symptoms block which pathway?

Answer 3

Blockade of the striatal dopamine pathway

Question 4

which generation antipsychotics would be prescribed if extrapyramidal side-effects were a particular concern?

Answer 4

1) Second generation: aripiprazole, clozapine, olanzapine, and quetiapine are least likely to cause extrapyramidal side-effects
2) Amisulpride (selectively blocks mesolimbic dopamine receptors only not striatal)

Question 5

Which antipsychotic drug is least likely to have an effect on QT interval?

Answer 5

1) Aripiprazole has negligible effect on the QT interval

2) Reduced tendency to prolong QT: clozapine, olanzapine, prochlorperazine, risperidone etc.

Question 6

Schizophrenia is associated with insulin resistance and diabetes. Is the following true or false :
The risk of diabetes is increased in patients with schizophrenia who take antipsychotic drugs?

Answer 6

TRUE

Question 7

1) Which generation of antipsychotic drugs are less likely to cause diabetes?
2) which drugs in this class have the lowest risk

Answer 7

1) First-generation less likely to cause diabetes

2) fluphenazine decanoate and haloperidol are lowest risk.

Question 8

Which second-generation antipsychotic drugs have the lowest risk of diabetes?

Answer 8

Amisulpride and aripiprazole have the lowest risk of diabetes of the second-generation

Question 9

Which antipsychotic drugs are least likely to cause weight gain?

Answer 9

Amisulpride, aripiprazole, haloperidol, etc.

Question 10

1) List the 2 antipsychotic drugs with the lowest risk of sexual dysfunction
2) Hyperprolactinaemia can cause sexual dysfunction, which drug can be considered if sexual dysfunction is judged to be as a result to this?

Answer 10

1) Aripiprazole and quetiapine

2) Olanzapine may be considered if sexual dysfunction is judged to be secondary to hyperprolactinaemia

Question 11

Aripiprazole, clozapine, olanzapine, and quetiapine are least likely to cause hyperprolactinaemia. When changing from other antipsychotic drugs, a reduction in prolactin concentration may increase what?

Answer 11

Fertility

Question 12

Patients should receive an antipsychotic drug for how many weeks before it is deemed ineffective?

Answer 12

4–6 weeks. Do not prescribe more than one at a time

Question 13

when would clozapine be used in the management of schizophrenia?

Answer 13

Introduced if schizophrenia is not controlled despite the use of two or more antipsychotics (one of which should be a 2nd gen), each for at least 6–8 weeks

Question 14

If symptoms do not respond adequately to an optimised dose of clozapine, how should a patient be managed?

Answer 14

1) checl plasma-clozapine concentration

2) Add a second antipsychotic drug allow 8–10 weeks treatment to assess response

Question 15

who should patients be registered with if they are receiving treatment with clozapine?

Answer 15

clozapine patient monitoring service

Question 16

outline the monitoring required for those on antipsychotics (5)

Answer 16

1) FBC, U&E’s, and LFT is required at the start of therapy and then annually thereafter
2) Blood lipids and weight should be measured at baseline, at 3 months, and then yearly.
3) Fasting blood glucose should be measured at baseline, at 4–6 months, and then yearly
4) before initiating ECG may be required, particularly with cardiovascular risk factors
5) BP monitoring is advised before starting therapy and frequently during dose titration

Question 17

which antipsychotic is used in deviant antisocial sexual behaviour ?

Answer 17

Benperidol

Question 18

Explain when antipsychotic depot injections might be used in patients, and outline the problems associated with using these dosage forms

Answer 18

1) Long-acting depot injections are used for maintenance therapy especially when compliance with oral treatment is unreliable
2) Higher incidence of extrapyramidal reactions than oral preparations; (extrapyramidal less likely with 2nd gen depot e.g. risperidone and olanzapine embonate)

Question 19

Which one of the following depot preperations would be more suitable for the treatment of agitated or aggressive patients:

1) Zuclopenthixol
2) Flupentixol decanoate

Answer 19

1) Zuclopenthixol may be suitable for the treatment of agitated or aggressive patients. (Also more effective in preventing relapses compared to other depot preps)
2) Flupentixol decanoate can cause over-excitement in such patients