Hi, Benadryl contains Diphenhydramine which is an antihistaminic which is prescribed for allergic reactions, hay fever, runny nose, water eyes and several other acute histaminic reactions. It is metabolized by the liver up to 50 to 60%. Hence, there is more chance for liver injury. The injury effect is more when there is any other associated toxic drug intake. Liver status can be assessed by evaluating the enzyme status. Liver specific enzymes are increased following liver injury. Jaundice may be seen in some individuals. Depends on the level of damage, the enzyme levels are raised. The response to antidote and other management can be diagnosed with level of enzymes. 50 mg is within the normal therapeutic range. But, repeated Liver assessment is necessary to rule out acute liver injury. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pradeepraj, General & Family Physician