Mefenamic Acid

4.2

4.5

4.2

PKA 4.2

152.3 Ų [M]+ [CCS Type: DT; Buffer gas: N2; Ionization: APCI+; Dataset: TOXCAST; Source Identifier: DTXSID5023243]

150.5 Ų [M+H]+ [CCS Type: TW]

153.3 Ų [M+H]+ [CCS Type: TW; Method: calibrated with polyalanine and drug standards]

153.25 Ų [M+H]+

...DIARRHEA IS COMMON & OFTEN SEVERE, & GI ULCERATION & BLEEDING HAVE BEEN REPORTED. EXACERBATION OF ASTHMA, AUTOIMMUNE HEMOLYTIC ANEMIA, ALBUMINURIA, & SLIGHT ELEVATION OF BLOOD UREA NITROGEN MAY OCCUR. AGRANULOCYTOSIS, THROMBOCYTOPENIC PURPURA, MEGALOBLASTIC ANEMIA, & PANCYTOPENIA HAVE BEEN REPORTED.

...UNDESIRED EFFECTS INCL DROWSINESS, NAUSEA, DIZZINESS, NERVOUSNESS, & HEADACHE.

MINOR REACTIONS INCL...VOMITING, URTICARIA, RASH, EOSINOPHILIA, BLURRED VISION, INSOMNIA, & PERSPIRATION. RARELY, PALPITATIONS, FACIAL EDEMA, DYSPNEA, EYE PAIN, EAR PAIN, DYSURIA, HEMATURIA, REVERSIBLE LOSS OF COLOR VISION, & INCR INSULIN NEED IN DIABETIC PT. MILD RENAL & HEPATIC TOXICITY HAVE ALSO BEEN REPORTED.

MEFENAMIC ACID IS A PROSTAGLANDIN SYNTHETASE INHIBITOR.

For more Human Toxicity Excerpts (Complete) data for MEFENAMIC ACID (7 total), please visit the HSDB record page.

Drug Induced Liver Injury Rank (DILIrank 2.0)

Mefenamic acid

vMost-DILI-concern

8

Warnings & precautions

DOI:10.1016/j.drudis.2016.02.015

1.25-10 MUG/KG CATS & 5-40 MG RATS GAVE PROGRESSIVE DOSE-RELATED INCR OF VOLTAGE OF BASELINE EEG PATTERNS. HIGH DOSES: SLOW WAVES & FUSIFORM COMPLEXES; IRRITATIVE ACTIVITY WITH SPIKES & COMPLEXES OF POLYSPIKES.

EEG MEFENAMIC ACID IN CATS & RATS GIVES CENTRAL SHORT-LASTING DEPRESSANT EFFECTS @ LOW DOSES & FACILILTATING OR STIMULANT EFFECTS @ HIGH DOSES.

Mefenamic acid

23.3

98.6

For the relief of acute pain in adults and adolescents ≥ 14 years of age, the recommended dose is 500 mg as an initial dose followed by 250 mg every 6 hours as needed, usually not to exceed one week.

Data used to generate the benchmarks include the following: Lowest Daily Dose (LDD): 1000 mg/day, Lowest Therapeutic Dose (LTD): 12.5 mg/kg-day, and Screening Dose: 0.004 mg/kg-day.

29-Nov-21

Anti-inflammatory agents that are non-steroidal in nature. In addition to anti-inflammatory actions, they have analgesic, antipyretic, and platelet-inhibitory actions. They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins. Inhibition of prostaglandin synthesis accounts for their analgesic, antipyretic, and platelet-inhibitory actions; other mechanisms may contribute to their anti-inflammatory effects.

Compounds or agents that combine with cyclooxygenase (PROSTAGLANDIN-ENDOPEROXIDE SYNTHASES) and thereby prevent its substrate-enzyme combination with arachidonic acid and the formation of eicosanoids, prostaglandins, and thromboxanes.

Mefenamic acid is rapidly absorbed after oral administration.

The fecal route of elimination accounts for up to 20% of the dose, mainly in the form of unconjugated 3-carboxymefenamic acid.3 The elimination half-life of mefenamic acid is approximately two hours. Mefenamic acid, its metabolites and conjugates are primarily excreted by the kidneys. Both renal and hepatic excretion are significant pathways of elimination.

1.06 L/kg [Normal Healthy Adults (18-45 yr)]

Oral cl=21.23 L/hr [Healthy adults (18-45 yrs)]

CROSSES PLACENTAL BARRIER IN MONKEYS...EXCRETED IN URINE, BILE &/OR FECES...

ABSORBED SLOWLY FROM GI TRACT...HIGH PERCENTAGE...BOUND TO PLASMA PROTEINS. PEAK PLASMA LEVELS APPEAR IN 2 TO 4 HR...ANALGESIA MAY PERSIST FOR UP TO 6 HR...ABOUT 50%...IS EXCRETED IN URINE WITHIN 24 HR /HUMAN, ORAL/