See the DrugPatentWatch profile for doxycycline

There is no direct scientific evidence to suggest that doxycycline, an antibiotic commonly used to treat various types of bacterial infections, affects Lipitor's (atorvastatin) cholesterol-lowering potency [1].

Doxycycline and Lipitor are metabolized differently in the body. Doxycycline is primarily metabolized by the liver, while Lipitor is metabolized by the liver through several pathways, including by the cytochrome P450 3A4 isoenzyme [2][3].

Although both medications are processed in the liver, they do not have a known interaction that would suggest one drug affects the other's therapeutic effect [1]. However, it is always important to inform healthcare providers of all medications being taken, as individual patient factors and other drug interactions can potentially impact drug effectiveness or increase the risk of adverse effects [4].

In summary, there is no evidence to suggest that doxycycline affects Lipitor's cholesterol-lowering potency based on the available information [1][2][3][4].

Sources:
[1] DrugPatentWatch.com, "Doxycycline and Atorvastatin (trade name Lipitor) Interaction," <https://www.drugpatentwatch.com/interactions/doxycycline-and-atorvastatin-trade-name-lipitor>.
[2] RxList, "Doxycycline," <https://www.rxlist.com/doxycycline-drug.htm>.
[3] RxList, "Atorvastatin (Lipitor)," <https://www.rxlist.com/lipitor-drug.htm>.
[4] Mayo Clinic, "Drug interactions: What is a drug-drug interaction?" <https://www.mayoclinic.org/diseases-conditions/drug-interactions/symptoms-causes/syc-20376700>.