That's great info that bonzodog has shared. Has this gone away? Hope so.
I found this answer to your question - apparently, Pradaxa CAN cause this side effect:
Good day and thank you for being with healthcare magic!!!
Yes pradaxa would make you at risk for bleeding in the seminal vesicle especially after sexual activity or rigorous ejaculation. It is also better to have your prostate checked to rule out prostate pathology that may cause the blood in the semen.
Prostate should be checked by serum PSA, ultrasound and a digital rectal examination by a urologist.
Majority of blood in the semen are self limiting and goes away on its own. You might need to abstain for 1-2 weeks from ejaculation and everything will become normal.