Melfen 400 mg is the name for Ibuprofen 400 mg a non-steroidal anti-inflammatory drugs (NSAIDs). These medicines reduce pain and inflammation thus they should be used according to the level of pain reported by each patient. Depending on pain, Ibuprofen prescription may go form 400 to 800 mg every six to eight hours. As most of the NSAIDs, even Ibuprofen alters blood pressure and may cause damage of the stomach. So I would suggest you to take Ibuprofen 400 mg for 20 days and to add an Esemoprasol 20 mg every morning before eating and taking Ibuprofen. If the pain gets stronger it should be appropriate to change to some other NSAID that is more stronger as a painkiller.