Tylenol PM is an over the counter medication used to treat pain, fever, watery eyes and sleeplessness. Tylenol PM contains two active ingredients, acetaminophen and diphenhydramine , that work together to reduce pain and allergic reactions due to histamine in the body. Prolonged or extensive use of Tylenol PM can result in dangerous effects such as liver toxicity, diphenhydramine overdose and psychological dependence.
Liver Damage
Acetaminophen is an active ingredient in Tylenol PM, effective at relieving pain and fever. According to the Food and Drug Administration, excessive consumption acetaminophen can result in liver damage ranging from abnormalities in liver function to liver failure and even death. Most cases of liver damage occurs in patients who take more than the recommended dosage of acetaminophen, about 10 to 15g per day. The liver is the principal organ in which acetaminophen and other medicinal products are broken down and safely eliminated from the body. Consumption of excess amount of acetaminophen results in the formation of the compounds that are toxic to the liver cells, resulting in liver damage. Alcohol consumption while taking acetaminophen increases the risk of liver damage. Nausea, vomiting and loss of appetite are early symptoms of liver damage.
Diphenhydramine Overdose
Diphenhydramine is the second active ingredient in Tylenol PM. Diphenhydramine is an antihistamine drug that blocks the release of histamine thereby preventing the sneezing, itching, watery eyes and other symptoms associated with an allergic reaction. Diphenhydramine also has sedative properties, inhibiting the action of histamine in the brain thereby relieving sleeplessness. Excess consumption of diphenhydramine can result in diphenhydramine overdose manifested as dizziness, muscle weakness, fatigue, chest congestion and hallucinations and seizures in severe cases, notes Medline Plus.
Psychological Dependence
Since Tylenol PM has sedative properties used to relieve sleeplessness, people may become psychologically dependent or reliant on Tylenol PM to sleep. According to Tylenol.com, Tylenol PM has no physical addictive properties. However, extensive use of Tylenol PM causes the individual to become accustomed to the effects of Tylenol PM and may develop excessive sleeping problems without the aid of Tylenol PM.
