Mefenamic acid is white to greyish-white, odorless, microcrystalline powder with melting point of 230 -231 and water solubility of. Usually, you will only need to take it for the first to days of your period. If you are an older have kidney pirkt ponstel lets problems, liver disease, or heart take drugs such as diuretics or ACE or suffer from dehydration, Ponstel could damage your kidneys and should be used with caution. Pharmacokinetics Absorption: Mefenamic acid is rapidly absorbed after oral administration. Symptoms of Ponstel overdose may include: Drowsiness, lack of energy, nausea, stomach or abdominal pain, vomiting In severe cases, breathing problems and coma can develop. Patients should be informed about the signs and symptoms of serious skin manifestations and use of the drug should be discontinued at the first appearance of skin rash or any other sign of hypersensitivity.