hi, from my knowledge i havent seen cases of filarial worms passing through the semen but yes it can cause hydrocele formation that is swelling in the scrotum which can enlarge if left untreated. what i would suggest if you can get a specimen of semen containing the something to be investigated for. any medication has side effects, you should be carefull if you develop, itching and swelling of face, especially eyes fever enlarged lymph nodes skin rash visual disturbances - loss of vision; night blindness; tunnel vision Arthralgia (joint pain) headache malaise (unusual tiredness or weakness) Dizziness nausea or vomiting would suggest visit your physician for further review hope have been able to answer your query get well soon.