See the DrugPatentWatch profile for lipitor

There is currently no scientific evidence to suggest that Lipitor, a medication used to treat high cholesterol, becomes less potent when in close proximity to chlorinated water [1]. The effectiveness of Lipitor is determined by how the body metabolizes the drug, which is not directly affected by chlorinated water [2].

It is important to note that Lipitor, like many other medications, can be affected by changes in pH levels [3]. Chlorinated water typically has a pH level between 6.5 and 7.5 [4], which is within the range (pH 4-8) where Lipitor is considered stable [3].

Additionally, the FDA states that the majority of medications are not significantly affected by exposure to water, including chlorinated water [5].

In conclusion, based on the available information, there is no evidence to suggest that Lipitor is less potent when close to chlorinated water.

Sources:
[1] DrugPatentWatch.com, "Lipitor", https://www.drugpatentwatch.com/drugs/lipitor
[2] Mayo Clinic, "Lipitor (Atorvastatin)", https://www.mayoclinic.org/drugs-supplements/lipitor-oral-route/description/drg-20063054
[3] US Food and Drug Administration, "Stability Testing of Drug Substances and Products", https://www.fda.gov/media/71132/download
[4] Centers for Disease Control and Prevention, "Chlorine in Drinking Water", https://www.cdc.gov/healthywater/drinking/private/chlorine-disinfection.html
[5] US Food and Drug Administration, "Can Drinking Water Affect My Medicines?", https://www.fda.gov/consumers/consumer-updates/can-drinking-water-affect-my-medicines