Hi,
Your friend should seek medical attention as soon as possible. Pain in the 
liver can be a sign of serious medical conditions and should not be ignored. He needs to get a proper diagnosis from a qualified healthcare provider.
Once a diagnosis is made, the healthcare provider will recommend the appropriate treatment, which may include medication to manage the pain. Common medications for liver pain include 
acetaminophen (
Tylenol) and nonsteroidal anti-inflammatory drugs (NSAIDs) such as 
ibuprofen or 
naproxen. However, it is important to note that in cases of liver disease, the use of NSAIDs may be contraindicated, and therefore, should only be taken under the guidance of a healthcare professional.
In addition to medication, lifestyle changes such as 
weight loss, exercise, and dietary modifications may be recommended to improve liver function and reduce the risk of complications. Your friend should discuss these options with his healthcare provider.
It is also important to note that taking 
Advil PM nightly is not a long-term solution and can have harmful effects on the liver and other organs. Your friend should avoid self-medicating and only take medications as prescribed by a healthcare professional.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Priyanka, General & Family Physician