Based on the available information, there are several reasons why someone might choose to stop taking Lipitor (atorvastatin) as directed. However, it's important to note that any decision to stop taking a medication should be made in consultation with a healthcare provider.

One possible reason for stopping Lipitor is the experience of side effects. According to the Cleveland Clinic, some people may experience side effects when they stop taking statins like Lipitor, which can include [2]:

* Muscle aches or weakness
* Nausea or vomiting
* Dizziness
* Insomnia
* Flu-like symptoms

In some cases, these symptoms may be severe enough to prompt a person to stop taking the medication. However, it's important to note that these symptoms are usually temporary and will go away on their own within a few weeks [2].

Another possible reason for stopping Lipitor is concern about long-term side effects or the belief that the medication is no longer necessary. For example, some people may choose to stop taking statins if they have been able to lower their cholesterol levels through diet and exercise [1]. However, this should only be done under the guidance of a healthcare provider, as stopping statins can increase the risk of heart attack or stroke [3].

It's also worth noting that Lipitor and other statins have been the subject of some controversy in recent years, with some studies suggesting that the benefits of the drugs may not outweigh the risks for certain groups of people [1]. However, the overwhelming consensus among medical experts is that statins are safe and effective for most people when used as directed [3].

In summary, there are several possible reasons why someone might choose to stop taking Lipitor as directed, including side effects, concern about long-term risks, or the belief that the medication is no longer necessary. However, it's important to consult with a healthcare provider before making any changes to medication regimens.

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
[2] <https://health.clevelandclinic.org/what-are-the-side-effects-of-stopping-statins>
[3] <https://www.healthline.com/health/high-cholesterol/how-to-safely-come-off-statins>