Dear Dr. Srivastava. Many thanks for your reply. Does the information you provided in your reply (hereunder)still remains
valid for the Klacid XL antibiotics which the box says they are 500mg (Modified release tablets)? Many thanks.Dr. Srivastava
wrote Hello,Thank you again for showing faith on this forum. I appreciate your query now that thoroughly explaining your
doubt. The answer I wrote earlier was also in same context that "if your wife becomes pregnant and even then you are on
medication. It will not at all harm upcoming baby pregnancy since clarithromycin does not appear in semen or affect semens
quality by any mean". Firstly, because clarithromycin has a rapid first pass hepatic (liver) metabolism and it is mainly
excreted through bile (ultimately in stool) and partly in urine. Secondly, if there is any amount of metabolites present in
your urine and body secretion would be insignificant to cause any harmful effect to forthcoming fetus. Thirdly, any major
male mediated teratogenic effects (harmful effect to baby from father's medication) is only possible when there is any
change in genes of the sperm of father since only the nuclei (gene portion) of sperm contributes to the fetus therefore for
any harmful effect of some drug, the genes mutation is required which may not be drastically possible in short term or single
course of any antibiotics including clarithromycin. Though there are some suspected drugs (excluding clarithromycin and other
commonly used antibiotics) which may have some effect on sperm's motility and viability in rare cases but genetic
make-up remains unchanged and that also are under researches to finally prove their effect. Therefore you may continue your
medicine course as prescribed until your doctor makes a comment in this regard. Hope this helps. Do keep us posted in case of
any further doubts or feedbacks. Take care.
