The main drugs which induce hyperprolactinaemia are:
- major tranquilisers - block dopamine binding sites
- metoclopramide - block dopamine binding sites
- tricyclic antidepressants - block catecholamine re-uptake
- reserpine - depletes catecholamines
- methyl-dopa - blocks conversion of tyrosine to dihydroxyphenylalanine and dopamine
- oral contraceptives - promote the synthesis and storage of prolactin
- bendrofluazide, omeprazole, ranitidine, cimetidine and famotidine have occasionally been reported to cause hyperprolactinaemia
Drug-induced increases in serum prolactin do not generally lead to levels above 2500 mU/L; however occasionally levels up to 6000 mU/L have been observed (1).
In cases of suspected drug-induced hyperoprolactinaemia where very high levels of prolactin are seen (over 2500 mU/L) then detailed physical examination (including visual fields), pituitary imaging and measurement of pituitary hormone levels are indicated.
- (1) Prescribers' Journal (2000), 40 (2), 157-168.