Tolfenamic acid (N-(2-methyl-3-chlorophenyl) anthranilic acid) belongs to the fenamate group and is a potent inhibitor of cyclo-oxygenase enzyme, thus inhibiting the synthesis of important inflammatory mediators such as thromboxane (Tx)B2 and prostaglandin (PG)E2. It acts not only by inhibiting prostaglandin synthesis, but it also has a direct antagonistic action on its receptors.
After oral administration, efficient blood levels are rapidly reached (CMAX is reached within 1 to 2 hours in fasted animals, or 2 to 4 hours when administered with the meal) and maintained sufficiently high to exert a satisfactory anti-inflammatory action for at least 24 to 36 hours.
Tolfedine should be discontinued with cats that show signs of anorexia, diarrhoea or vomiting. Regular blood testing of renal function is highly recommended.
Recommended dose in dogs is 4 mg/kg given IM, SQ or orally every 24 hours up to 5 days, 3 out of 7 days for long term therapy.
- Hugonnard M et al (2004) Attitudes and concerns of French veterinarians towards pain and analgesia in dogs and cats. Vet Anaesth Analg 31(3):154-163