Four studies (all RCTs) were identified (743 patients, range 34 to 459). Three studies were B quality and one was A quality.
Normalisation of serum prolactin level was significantly improved for cabergoline versus bromocriptine (WMD 0.67, 95% CI 0.57 to 0.80; Ι²=54%, four RCTs). Cabergoline also significantly reduced persistent amenorrhoea compared to bromocriptine (RR 2.18, 95% CI 1.43 to 3.32; Ι²=0%, three studies) but there was no significant benefit for persistent galactorrhoea (Ι²=45%; three studies). There was a higher frequency of menses normalisation and return of normal ovulatory cycles for cabergoline versus bromocriptine (RR 0.74, 95% CI 0.67 to 0.83; Ι²=0%, three studies).
The number of adverse events was significantly higher for bromocriptine versus cabergoline (RR 1.43, 95% CI 1.03 to 1.98; Ι²=70%, four studies). Two studies provided suitable data for subgroup analyses for different adverse events and found both nausea (RR 1.66, 95% CI 1.33 to 2.06) and vomiting (RR 2.02, 95% CI 1.13 to 3.59) were significantly lower for cabergoline versus bromocriptine. There were no significant differences for any of the other specific adverse events evaluated.
Some additional individual study results were reported.