In relation to use as a diagnostic aid: anticonvulsants (eg phenytoin, barbiturates), anti-depressants and neuroleptics (eg amitriptyline, chlorpromazine), hormones that affect the hypothalamo-pituitary axis and anti-thyroid agents may influence the results of the Metopirone test. If these drugs cannot be withdrawn, the necessity of carrying out the Metopirone test should be reviewed.
If adrenocortical or anterior pituitary function is more severely compromised than indicated by the results of the test, Metopirone may trigger transient adrenocortical insufficiency. This can be rapidly corrected by giving appropriate doses of corticosteroids.
Long-term treatment with Metopirone can cause hypertension as the result of excessive secretion of desoxycorticosterone.
The ability of the adrenal cortex to respond to exogenous ACTH should be demonstrated before Metopirone is employed as a test, as Metopirone may induce acute adrenal insufficiency in patients with reduced adrenal secretory capacity, as well as in patients with gross hypopituitarism.
Patients with liver cirrhosis often show a delayed response to Metopirone, due to liver damage delaying the metabolism of cortisol.
In cases of thyroid hypofunction, urinary steroid levels may rise very slowly, or not at all, in response to Metopirone.
Patients with ectopic Cushing's syndrome are at risk from opportunistic infections such as Pneumocystis Jirovecii pneumonia (previously termed Pneumocystis carinii pneumonia) during Metopirone treatment. Appropriate prophylactic treatment may be considered in this population.
When Metopirone is used as ACTH suppression test a diminished response was observed during pregnancy.
Excipients
Sodium ethylparaben (E215) and sodium propylparaben (E217) may cause allergic reactions (possibly delayed).
This medicine contains less than 1 mmol sodium (23 mg) per capsule, that is to say essentially 'sodium free'.