Based on the information its seems that you are having prolactinoma, but MRI shows its normal, hence you are treated with sicriptin which is the drug of choice for the milk discharge.
following are the side effect of that drug.
2) spinning sensation,
3) mild drowsiness
4) feeling tired;
5) mild headache,
6) depressed mood,
7) sleep problems (insomnia
8) dry mouth
9) stuffy nose;
10) upset stomach, nausea, vomiting
, stomach pain, loss of appetite, diarrhea
, constipation; or
11) cold feeling or numbness in your fingers.
If you think the side effects are not tolerable contact you gynec and let her know about it and she can change the prescription.
Hope it helps.