Lipitor is a medication used to lower cholesterol levels in the blood. According to Drug Patent Watch [1], the patent for Lipitor expired in 2011, meaning that generic versions of the drug are now available.

Statins, including Lipitor, have been known to cause side effects, such as muscle pain and weakness. However, a study published in the Annals of Internal Medicine found that the benefits of statins outweigh the risks of side effects [2].

As for whether symptoms persist after stopping Lipitor, the National Center for Biotechnology Information [3] explains that muscle symptoms associated with statins typically resolve within a few weeks of discontinuing the medication. However, in rare cases, muscle symptoms may persist for months or even years after stopping the medication.

In summary, while Lipitor and other statins may cause side effects such as muscle pain and weakness, the benefits of these medications outweigh the risks. Muscle symptoms associated with statins typically resolve within a few weeks of discontinuing the medication, but in rare cases, symptoms may persist for months or even years.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.cnn.com/2017/07/24/health/statins-side-effects-outcomes-study/index.html
[3] https://www.ncbi.nlm.nih.gov/books/NBK548236/