Transdermal patches can be a very precise time released method of delivering a drug. Cutting a patch in half might affect the dose delivered. The release of the active component from a transdermal delivery system (patch) may be controlled by diffusion through the adhesive which covers the whole patch, by diffusion through a membrane which may only have adhesive on the patch rim or drug release may be controlled by release from a polymer matrix. Cutting a patch might cause rapid dehydration of the base of the medicine and affect the rate of diffusion.
In using antibiotics to treat rosacea, the physician or dermatologist generally starts with a milder version of an oral antibiotic such as Oracea or Tetracycline and should be tapered off in three to five months but have been found to be prescribed for much longer periods of time. Because bacteria mutate very quickly the initial antibiotic may lose its effectiveness in just a few months. If the symptoms have shown improvement over this time, the decision may be made to switch to a topical antibiotic rather than a stronger oral antibiotic.