Ringing in the ears fast pounding heartbeat, mental mood changes, stomach pain, difficult painful swallowing, swelling of the ankles feet hands, sudden unexplained weight gain, vision changes. Always consult your health care professional before using this, or any other, drug. If you think you may have medical emergency, call your doctor or 911 immediately. Do not take mefenamic acid with antacids unless directed by your ordni jew jixtru ponstel online doctor. The apparent volume of distribution Vzss estimated following 500-mg oral dose of mefenamic acid was. NSAID medicines should not be used by pregnant women late in their pregnancy. If you suspect an overdose, seek medical attention immediately.