Hi Welcome to Health Care Magic......
is mefenemic acid which belongs to a group of NSAID Non steroidal antiinflammatory drugs.They are good when taken for acute problems and for a short course . Long time ingestion has many problems - It causes - Gastritis
, Renal problems - if taken for long can cause Renovascular hypertension
, renal failure
, It also has antiplatelet effect and so increases chances of blood loss leading to low heamoglobin-Anaemia
.My advice get your headache evaluated - know the cause and get an appropriate medication.Try avoiding it to extent possible for it has many sideeffects on long term use.