Can doxycycline be shared in harmful levels via saliva/semen?

I've just started taking 100mg of Doxycyline per day (to continue for a week, after which I am to take one per week for 23 weeks).  This is to keep me from developing further chalazia, following the excision of a few two days ago, and was prescribed by the ophthalmologist I visited.

My dilemma is:  I am visiting my fiancée in a few days and she is mildly allergic to penicillin (which I know doxcycline is unrelated to) as well as has been warned by her doctors not to take practically any antibiotics/antihistamines/most medication, due to her heart condition (noncompactive cardiomyopathy of the left ventricle) as well as her allergies to various other common things.

Essentially, I'm worried about passing any dosage of doxycycline on to her via saliva/semen.  Do you think the fairly small dosage of doxycycline I'm taking could potentially dilute into my bodily fluids enough to cause her any harm?

[Bhupinder Kaur, MD]

Hello,
Doxycycline has a half life of 18-22 hrs and is excreted primarily in the urine and bile.Nothing has been reported so far about its excretion in saliva or semen.

I hope that helps. Take care and pls do keep me posted on how you are doing or if you have any additional queries. Kind regards