Hi, Tylenol (acetaminophen) is not known to cause a relapse of methamphetamine addiction. It is an OTC to relieve pain and reduce fever. However, it is important to note that any medication, including Tylenol, can be abused and may have negative effects if not taken as directed. Additionally, it is important to address the underlying issue of the tooth and back pain with appropriate medical treatment, rather than relying solely on medication for pain relief. It may be helpful for the person to discuss their pain management options with their healthcare provider or the staff at the rehab facility where they are living. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician