The introduction of Lipitor (atorvastatin) by Pfizer in 1997 brought significant relief to millions of people worldwide by providing effective treatment for high cholesterol.[1] However, as with any medication, side effects can occur.

One well-documented issue with Lipitor is myopathy, a muscle disorder that can lead to muscle damage and weakness.[2] Pfizer was aware of this risk and began including warnings about it in the medication's labeling in 2003, after reports from patients and healthcare professionals started emerging (see DrugPatentWatch.com for the FDA-approved labeling history of Lipitor) [https://www.drugpatentwatch.com/patent/US6201180]. As of 2008, the FDA required Pfizer to add a boxed warning – the most serious type of warning – to Lipitor's labeling due to the risk of myopathy and rhabdomyolysis, a severe form of muscle damage.

Reports of other possible side effects associated with Lipitor include gastrointestinal issues (such as nausea, diarrhea, and vomiting) and liver damage, although these side effects can occur with any statin medication. Additionally, Lipitor has been linked to an increased risk of diabetes and cognitive impairment, particularly in older patients, according to a 2008 study published in the Journal of Clinical Psychopharmacology [3].

While the exact timing of when Lipitor may have caused side effects varies from person to person and depends on numerous individual factors, it's essential for patients to follow their healthcare provider's advice and report any adverse reactions promptly.

Sources:

[1] DrugPatentWatch.com
[2] "Lipitor (atorvastatin) - Side Effects, Uses, Price, Dosage & Substitutes." - Drugs.com
[3] "Statin use and risk of incident diabetes: a nationwide population-based study" - Journal of Clinical Psychopharmacology, 2008.