According to the information provided, Lipitor (atorvastatin) is an effective medication for managing high cholesterol levels. Lipitor belongs to a class of drugs called statins, which work by reducing the amount of cholesterol produced by the body [1].

Clinical studies have shown that Lipitor is effective in lowering low-density lipoprotein (LDL) cholesterol, also known as "bad" cholesterol, and increasing high-density lipoprotein (HDL) cholesterol, or "good" cholesterol [2]. Additionally, Lipitor has been found to reduce the risk of stroke, heart attack, and other cardiovascular events in patients with high cholesterol and related conditions [3].

It is important to note that Lipitor is a prescription medication and should be used under the guidance of a healthcare professional. The dosage and duration of treatment may vary depending on the individual patient's medical history, current health status, and response to treatment [4].

In terms of availability, Lipitor is a widely prescribed medication and is available in various forms, including tablets and oral suspension [5]. The drug is manufactured by Pfizer and its patent expired in 2011, leading to the introduction of generic versions of atorvastatin [6].

In summary, Lipitor is an effective medication for managing high cholesterol levels and reducing the risk of cardiovascular events. It is a widely available prescription medication and should be used under the guidance of a healthcare professional.

Sources:

1. Mayo Clinic. (2021). Lipitor (Atorvastatin). <https://www.mayoclinic.org/drugs-supplements/lipitor-oral-route/description/drg-20063081>.
2. National Library of Medicine. (2021). Atorvastatin. <https://medlineplus.gov/druginfo/meds/a601263.html>.
3. Baigent, C., Blackwell, L., Emberson, J., Holland, L. E., Reith, C., & Bhala, N. (2010). Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 11 randomised controlled trials. The Lancet, 376(9753), 1670-1681. <https://doi.org/10.1016/S0140-6736(10)61350-5>.
4. Drugs.com. (2021). Lipitor. <https://www.drugs.com/lipitor.html>.
5. National Library of Medicine. (2021). Atorvastatin calcium. <https://dailymed.nlm.nih.gov/druginfo/drugshis/2-50765-4815-5.html>.
6. DrugPatentWatch. (2021). Lipitor (Atorvastatin) Patent Expiration & Generics. <https://www.drugpatentwatch.com/patent/lipitor-atorvastatin/>.