In situations where a clear dose-response relationship exists for the drug in question, monitoring drug serum levels where there is a narrow therapeutic margin helps maintain the dose in a range...
If the medications is for your period or due to a hormonal problem or Birth Control then this can delay your period. Any other medication shouldn't effect your period.
you dont touch it!
you tip from bottle to cup and so on - the only actual hand contact -if any- will be the person taking the medication. the process is not likely to be antiseptic so is differetn...