Calefenac

Uses

Aceclofenac is used for the relief of pain and inflammation in both acute and chronic pain like osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, dental pain, post-traumatic pain, low back pain, gynaecological pain etc.

Methyl salicylate is a topical counter-irritant used for the symptomatic relief of acute musculoskeletal pain in the muscles, joints, and tendons.

Ointments or liniments containing methyl salicylate are applied topically as counter irritant for relief of acute pain associated with lumbago,sciatica and rheumatic conditions. Local analgesics for human and veterinary medicine.

Calefenac is also used to associated treatment for these conditions: Ankylosing Spondylitis (AS), Osteoarthritis (OA), Rheumatoid ArthritisAcute Muscle Pain, Arthritis, Back Pain Lower Back, Backache, Contusions, Joint Pain, Ligament pain, Muscle Inflammation, Muscle Injuries, Muscle Strain, Muscle swelling, Pain, Pain of the Bone and Bones, Pain, Nerve, Partial-Onset Seizures, Postherpetic Neuralgia, Soreness, Muscle, Sprains, Tendon pain, Minor aches, Muscle, joint pains

How Calefenac works

Through COX-2 inhibition, aceclofenac downregulates the production of various inflammatory mediators including prostaglandin E2 (PGE2), IL-1β, and TNF from the arachidonic acid (AA) pathway. Inhibition of IL-6 is thought to be mediated by diclofenac converted from aceclofenac . Suppressed action of inflammatory cytokines decreases the production of reactive oxygen species. Aceclofenac is shown to decreased production of nitrous oxide in human articular chondrocytes . In addition, aceclofenac interferes with neutrophil adhesion to endothelium by decreasing the expression of L-selectin (CD62L), which is a cell adhesion molecule expressed on lymphocytes . Aceclofenac is proposed to stimulate the synthesis of glycosaminoglycan in human osteoarthritic cartilage which may be mediated through its inhibitory action on IL-1 production and activity . The chrondroprotective effects are generated by 4'-hydroxyaceclofenac which suppresses IL-1 mediated production of promatrix metalloproteinase-1 and metalloproteinase-3 and interferes with the release of proteoglycan from chrondrocytes .

Counter-irritation is thought to be effective at alleviating musculoskeletal pain as the irritation of the sensory nerve endings is thought to alter or offset pain in the underlying muscle or joints that are served by the same nerves . This is thought to mask the underlying musculoskeletal pain and discomfort. When applied topically, methyl salicylate is thought to penetrate the skin and underlying tissues where it reversibly inhibits cyclooxygenase enzyme and locally and peripherally prevents the production of inflammatory mediators such as prostaglandin and thromboxane A2.

Dosage

Calefenac dosage

Adults: The maximum recommended dose is 200 mg daily, taken as two separate 100 mg doses, one tablet in the morning and one in the evening.

Children: There is no clinical data on the use of aceclofenac in children.

Elderly: The pharmacokinetics of aceclofenac are not altered in elderly patients, therefore it is not considered necessary to modify the dose and dose frequency.

Renal insufficiency: There is no evidence that the dosage of aceclofenac needs to be modified in patients with mild renal impairment.

Hepatic insufficiency: The dose of aceclofenac should be reduced in patients with hepatic impairment. An initial daily dose of 100 mg should be administered.

Aceclofenac SR tablet:

The recommended dose is 200 mg once daily.

Side Effects

Generally aceclofenac is well tolerated. The majority of side effects observed have been reversible and of a minor nature and include gastrointestinal disorders (dyspepsia, abdominal pain, nausea and diarrhoea) and occasional occurance of dizziness. Dermatological side effects including pruritus and rash. Abnormal hepatic enzyme levels and raised serum creatinine have occasionally been reported.

Toxicity

Some common adverse effects include gastro-intestinal disorders (dyspepsia, abdominal pain, nausea), rash, ruber, urticaria, symptoms of enuresis, headache, dizziness, and drowsiness . Oral LD50 value in rats is 130 mg/kg .

Oral LD50 values (mg/kg) for mouse, rat and rabbit are 1110, 887 and 1300, respectively. Oral LD50 values for child and adult human (mg/kg) are 228 and 506, respectively. Although systemic toxicity from topical administration is rare, methyl salicylate can be absorbed in intract skin to cause stimulation of the central nervous system respiratory center, disturbance of lipid and carbohydrate metabolism, and disturbance of intracellular respiration. Severe toxicity can result in acute lung injury, lethargy, coma, seizures, cerebral edema, and death. In case of salicylate poisoning, the treatment consists of general supportive care, gastrointestinal decontamination with activated charcoal in cases of salicylate ingestion, and monitoring of serum salicylate concentrations. Bicarbonate infusions or hemodialysis can be used to achieve enhanced salicylate elimination .

Precaution

Aceclofenac should be administered with caution to patients with symptoms indicative of gastrointestinal disorders, with a history of peptic ulceration, ulcerative colitis, Crohn\'s disease, hepatic porphyria, and coagulation disorders. Patients suffering from severe hepatic impairment must be monitored.

Interaction

Lithium and Digoxin: Aceclofenac, like many NSAIDs may increase plasma concentrations of lithium and Digoxin.

Diuretics: Aceclofenac, like other NSAIDs, may interact the activity of diuretics.

Anticoagulants: Like other NSAIDs, Aceclofenac may enhance the activity of anticoagulant. Close monitoring of patients on combined anticoagulants and Aceclofenac therapy should be undertaken.

Methotrexate: Caution should be exercised if NSAIDs and Methotrexate are administered within 24 hours of each other, since NSAIDs may increase Methotrexate plasma levels, resulting in increased toxicity.

Volume of Distribution

The volume of distribution is approximately 25 L .

After absorption, methyl salicylate is distributed throughout most body tissues and most transcellular fluids, primarily by pH dependent passive processes. Salicylate is actively transported by a low-capacity, saturable system out of the CSF across the choroid plexus. The drug readily crosses the placental barrier.

Elimination Route

Aceclofenac is rapidly and completely absorbed from the gastrointestinal tract and circulates mainly as unchanged drug following oral administration. Peak plasma concentrations are reached around 1.25 to 3 hours post-ingestion, and the drug penetrates into the synovial fluid where the concentration may reach up to 60% of that in the plasma . There is no accumulation in regular dosing, with similar maximum plasma concentration (Cmax) and time to reach peak plasma concentration (Tmax) after single and multiple doses .

Approximately 12-20% of topically applied methyl salicylate may be systemically absorbed through intact skin within 10 hours of application, and absorption varies with different conditions such as surface area and pH. Dermal bioavailability is in the range of 11.8 – 30.7%. For the assessment of potential oral exposure to salicylates, bioavailability is assumed to be 100% .

Half Life

The mean plasma elimination half-life is approximately 4 hours .

The plasma half-life for salicylate is 2 to 3 hr in low doses and about 12 hr at usual anti-inflammatory doses. The half-life of salicylate may be as long as 15 to 30 hr at high therapeutic doses or when there is intoxication.

Clearance

The mean clearance rate is approximately 5 L/h .

Elimination Route

The main route of elimination is via the urine where the elimination accounts for 70-80% of clearance of the drug . Approximately two thirds of the administered dose is excreted via the urine, mainly as glucuronidated and hydroxylated forms of aceclofenac . About 20% of the dose is excreted into feces .

Excreted by kidneys as free salicylic acid (10%), salicyluric acid (75%), salicylic phenolic (10%) and acyl glucuronide (5%), and gentisic acid (less than 1%).

Pregnancy & Breastfeeding use

Pregnancy: There is no information on the use of aceclofenac during pregnancy. Aceclofenac should not be administered during pregnancy, unless there are compelling reasons for doing so. The lowest effective dose should be administered.

Lactation: There is no information on the secretion of aceclofenac in breast milk. The use of aceclofenac should therefore be avoided during lactation unless the potential benefits to the mother outweigh the possible risks to the children.

Contraindication

Aceclofenac should not be administered to patients with active or suspected peptic ulcer or gastro-intestinal bleeding. It should not be given to patients with moderate to severe renal impairment. Close medical surveillance is also imperative in patients suffering from severe impairment of hepatic function. It should not be prescribed during pregnancy, unless there are compelling reasons for doing so. The lowest effective dosage should be used. Aceclofenac should not be administered to patients previously sensitive to Aceclofenac or in whom aspirin or NSAIDs precipitate attacks of asthma, acute rhinitis or urticaria or who are hypersensitive to these drugs.

Acute Overdose

There is no human data available on the consequences of aceclofenac overdosage. After overdosage, following therapeutic measures to be taken: absorption should be prevented as soon as possible by means of gastric lavage and treatment with activated charcoal. Supportive and symptomatic treatment should be given for complications.

Storage Condition

Keep at a cool and dry place, protected from light and moisture.

Innovators Monograph

You find simplified version here Calefenac