A female patient, who has been prescribed a new antipsychotic whilst admitted to hospital, attends the outpatient clinic. They cannot recall the exact name of the medication but complain that they have started to notice excessive amounts of facial hair and that sex has become painful due to them being dry. On further questioning you discover that her periods have also stopped. Which of the following would be least likely to have caused these problems?
Exam Question Jul 2014
Note that the questions asks for the LEAST likely cause.
Exam Question Jul 2014
Note that the questions asks for the LEAST likely cause.
Antipsychotics (hyperprolactinaemia)
Hyperprolactinemia is associated with the use of antipsychotics (and very occasionally antidepressants). Dopamine inhibits prolactin and so dopamine antagonists increase prolactin levels.
All antipsychotics cause measurable changes in prolactin but some do not increase levels beyond the normal range. The degree of prolactin elevation is dose related.
It is often asymptomatic but is associated with the following:-
- Galactorrhoea and breast growth
- Amenorrhoea
- Gynaecomastia
- Hypogondism
- Sexual dysfunction
Psychiatric patients with long standing hyperprolactinaemia have an increased risk of:-
- Osteoporosis
- Breast cancer (females only)
Antipsychotics known to cause significant hyperprolactinaemia include:-
- All the typical antipsychotics
- Risperidone
- Amisulpride
- Zotepine
Drugs not usually associated with hyperprolactinaemia include:-
- Clozapine
- Aripiprazole
- Quetiapine
- Olanzapine
- Ziprasidone
Monitoring
All patients should have a their prolactin measured before antipsychotic therapy and then should be asked about symptoms at three months (and if symptoms present it should be measured again). In cases where there are no symptoms, annual testing is recommended.
Antipsychotics that increase prolactin should be avoided in the following (where possible):
- Patients under 25 (before peak bone mass)
- Patients with osteoporosis
- Patients with a history of hormone dependent cancer
Testing
Samples should be taken at least 1 hour after eating or waking. Care must be taken to avoid stress during the proceedure as this can elevate prolactin.
| Gender | Normal range |
|---|---|
| Male | 0-25 ng/ml (0-530 mlU/L) |
| Women | 0-20ng/ml (0-424 mlU/L) |
Treatment
In symptomatic cases or where there is concern about long-term risk (the actual prolactin level is not really a big deal) the options are:
- Switch to an alternative antipsychotic less prone to hyperprolactineamia
- Alternatively, aripiprazole (at 3-6 mg/day) can be added in as this can lower prolactin levels (note that this is a small dose as the minimally effective daily dose is 10 mg).
- The last option is to add a dopamine agonist such as amantadine or bromocriptine (but these have the potential to worsen psychosis).
Maudsley Guidelines 11th Edition.
