✔ 最佳答案
Ibuprofen is an NSAIDs (Non-steriodal inflammatory drugs), and NSAIDs is just a weak analgesic, comparing with Opoid anaglesic, e.g. morphine.
Normally all drugs are reckoned 'toxic' to the liver - It is the liver who metabolizes the drugs. The more/ longer term you take the drugs, the more toxicity is brought to the liver. Until now, there is no medical research showing ibuprofen leads to liver cancer, so don't worry about that.
For NSAIDs, the normal dose for adults should not exceed 3200mg/day. Particularly for the dysmenorrhea, in some medical journals they suggest the dose should be 400mg in every 4 hours if needed, but all these vary with different health condtion of the people.
The common side effects of ibuprofen are headache, dizziness, rash, constipation, nausea and dyspepsia, but whether presence or absence of side effects varies among people. If you are taking the right dose, normally no side effect is shown.
For your medication habit, if you take with doctor prescription, personally I don't see problem, unless you did not tell doctor for the side-effects/ any discomfort. Yet, if you are just taking over-the-counter medication (i.e. simply buy from shops), I suggest you better not to keep such habit, as you don't know the right dosage - Doctor will not just follow the 'normal dosage standard' - they will refer a lot of your body condtion - e.g. your body size, your medical history, allergic history... etc.
In here I can just tell you such information. In case of any doubt, seek professional advice.
參考: Karch (2005). Nursing Drug guide. New York: Lippincott Williams & Wilkins