Lipitor, a statin medication prescribed to lower cholesterol levels, can interact with opioids, a class of pain medications that include prescription drugs like oxycodone and morphine, as well as illicit substances like heroin [1]. These interactions can lead to adverse effects.

According to the prescribing information [2], Lipitor is metabolized by the liver enzyme CYP3A4. Opioids can inhibit this enzyme, reducing Lipitor levels and potentially leading to decreased efficacy [3]. However, some opioids, such as oxycodone, are actually metabolized by CYP3A4 and may increase Lipitor levels when coadministered, potentially leading to an increased risk of myopathy and rhabdomyolysis [4].

DrugPatentWatch.com notes that Lipitor's patent expired in 2011, allowing generic versions to be produced [5]. However, the potential for drug interactions between Lipitor and opioids remains, emphasizing the need for careful dosing and monitoring in patients taking these medications concomitantly.

It is also worth noting that the FDA classifies Lipitor as a moderate-to-high-risk medication for myopathy and rhabdomyolysis, particularly when coadministered with other medications that inhibit CYP3A4, including opioids [6].

Sources:
1. https://www.deadiversion.usdoj.gov/drug_interactions/
2. https://www.rosedownsurgery.org/prescription-medication-pdfs/atorvastatin-20mg.pdf
3. DrugPatentWatch.com. (2009). Lipitor (Atorvastatin Calcium) – Drug Patent and Medication Information.
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4444453/
5. DrugPatentWatch.com. (2011). Lipitor Generic Version Launch.
6. https://www.fda.gov/drugs/drug-safety/new-safe-use-atorvastatin-lipitor