Tolfenamic acid is approved in Canada and Europe in an oral and parenteral formulation for dogs and cats. In vitro data support COX-1–sparing (COX-2–selective) activity. By studying its NSAID properties more closely, it was noted a dose-related inhibition of serum thromboxane which indicated the inhibition of COX-1. In the same line, there was noted a inhibition of prostaglandin E2 synthesis which marks a related COX-2 inhibition. The maximal inhibition of thromboxane was greater than 80% as well as is proven to be a potent prostaglandin E inhibitor.
Mechanism of Action of Tolfenamic Acid
Tolfenamic acid inhibits the biosynthesis of prostaglandins, and it also presents inhibitory actions on the prostaglandin receptors. As commonly thought, the mechanism of action of tolfenamic acid is based on the major mechanism of NSAIDs which consists of the inhibition of COX-1 and COX-2 pathways to inhibit prostaglandin secretion and action and thus, to exert its anti-inflammatory and pain-blocking action. Nonetheless, some report currently indicates that tolfenamic acid inhibits leukotriene B4 chemotaxis of human polymorphonuclear leukocytes leading to an inhibition of even 25% of the chemotactic response. This activity is a not ligand specific additional anti-inflammatory mechanism of tolfenamic acid.
Indications of Tolfenamic Acid
- headaches and migraines
- a toothache
- period pains
- general aches and pains
- In the information for tolfenamic acid, it is stated that this drug, being an NSAID, is effective in treating the pain associated with the acute attack of migraines in adults
-
In the information for tolfenamic acid, it is stated that this drug, being an NSAID, is effective in treating the pain associated with the acute attack of migraines in adults.
-
Treatment of progressive supranuclear palsy
-
Treatment of behavioral variant frontotemporal dementia
Contra-Indications of Tolfenamic Acid
- Active peptic ulcer, aspirin/anti-inflammatory induced allergy, hepatic or renal impairment. Pregnancy (3rd trimester).
- Hypersensitivity to aspirin or other NSAID. Active or history of GI bleeding or ulceration, severe heart failure, history of GI bleeding or perforation related to previous NSAID therapy. Severe renal and hepatic impairment. Pregnancy (3rd trimester).
The Dosage of Tolfenamic Acid
- Strengths: 100mg ;200 mg
- 200 mg when 1st symptoms appear, may be repeated after 1-2 hr, if necessary.
Mild to moderate pain
- 100-200 mg tid.
Side Effects of Tolfenamic Acid
The most common
- Constipation
- dizziness
- drowsiness
- dry mouth
- chest pain
- a headache
- joint painPain
- dizziness
- nausea and vomiting
- Severe stomach ache
- epigastric pain,
- diarrhea,
- anorexia,
- flatulence,
- a headache,
- fainting, fast or pounding heartbeats.
More common
- Seizures
- Syndrome of inappropriate secretion of antidiuretic hormone
- Fast or irregular heartbeat
- fever
- Back pain
- dizziness
- headache
- increased cough
- Acid or sour stomach
- decreased appetite
- Agitation
- chest congestion
- chest pain
- cold sweats
- confusion
- decreased sexual ability or desire
- diarrhea or loose stools
- heartburn
- sleepiness or unusual drowsiness
- stomach or abdominal cramps, gas, or pain
- trouble sleeping
Less common
- Abnormal dreams
- change in sense of taste
- congestion
- discouragement, feeling sad, or empty
- Suicide attempts
- Acting on dangerous impulses
- Aggressive or violent behavior
- Thoughts about suicide or dying
- New or worse depression
- New or worse anxiety or panic attacks
- Agitation, restlessness, anger, or irritability
- Trouble sleeping
- An increase in activity or talking more than normal
Drug Interactions of Tolfenamic Acid
The tolfenamic acid may interact with following drugs, supplements & may decrease the efficacy of the drug
- angiotensin converting enzyme (ACE) inhibitors (e.g., ramipril)
- beta-adrenergic blockers (e.g., metoprolol, atenolol)
- corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone)
- cyclosporine
- diuretics (water pills; e.g., spironolactone, triamterene)
- heparin
- methotrexate
- “gliptin” diabetes medications (e.g.,metformin linagliptin, saxagliptin, sitagliptin)
- other NSAIDs (e.g., celecoxib, ibuprofen, ketorolac, naproxen)
- phenytoin
- potassium supplements
- selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, duloxetine, fluoxetine,paroxetine, sertraline)
- warfarin
Pregnancy & lactation of Tolfenamic Acid
FDA Pregnancy Category C
Pregnancy
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. The use of mefenamic acid during the last 3 months of pregnancy may result in harm to the baby or longer labour for the mother. Mefenamic acid should not be used during this time.
Lactation
This medication passes into breast milk. If you are a breast-feeding mother and are taking mefenamic acid, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
References
Explore this medical topic
Continue through verified related conditions, investigations, medicines, and patient guides. These links are educational and do not replace professional medical advice.
