Flexabenz Plus

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.

Flexor is used for an adjunct to rest and physical therapy for relief of muscle spasm associated with acute, painful musculoskeletal conditions. Improvement is manifested by relief of muscle spasm and its associated signs and symptoms, namely, pain, tenderness, limitation of motion, and restriction in activities of daily living.

Flexabenz Plus is also used to associated treatment for these conditions: Ankylosing Spondylitis (AS), Osteoarthritis (OA), Rheumatoid ArthritisMuscle Spasms

How Flexabenz Plus 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 .

The exact mechanism of action of cyclobenzaprine has not been fully elucidated in humans, and much of the information available regarding its mechanism has been ascertained from early animal studies. There is some evidence that cyclobenzaprine exerts its effects at the supraspinal level, specifically within the locus coeruleus of the brainstem, with little-to-no action at neuromuscular junctions or directly on skeletal musculature. Action on the brainstem is thought to result in diminished activity of efferent alpha and gamma motor neurons, likely mediated by inhibition of coeruleus-spinal or reticulospinal pathways, and ultimately depressed spinal cord interneuron activity.

More recently it has been suggested that inhibition of descending serotonergic pathways in the spinal cord via action on 5-HT2 receptors may contribute to cyclobenzaprine’s observed effects.

Dosage

Flexabenz Plus 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.

The usual dose is 5-10 mg three times daily given by mouth. The daily dose should not exceed 60 mg. Treatment for more than 2 or 3 weeks is not recommended.

Dose in elderly: Therapy with Flexor in the elderly should be initiated with a 5 mg dose and titrated slowly upward.

Dose in hepatic impairment: Flexor should be used with caution in subjects with mild hepatic impairment starting with the 5 mg dose and titrating slowly upward. The use of Flexor in subjects with moderate to severe impairment is not recommended.

Pediatric Use: Safety and effectiveness of Cyclobenzaprine Hydrochloride in pediatric patients below 15 years of age have not been established.

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.

The adverse reactions reported most frequently with Cyclobenzaprine Hydrochloride are drowsiness, dry mouth and dizziness. The incidence of these common adverse reactions is lower in the surveillance program than in the controlled clinical studies.

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 .

The oral LD₅₀ of cyclobenzaprine in mice and rats is 338 mg/kg and 425 mg/kg, respectively. Signs of overdose may develop rapidly after ingestion and commonly include significant drowsiness and tachycardia, with less common manifestations including tremor, agitation, ataxia, GI upset, and other CNS effects such as confusion and hallucinations. Potentially critical manifestations, though rare, include cardiac arrest or dysrhythmias, severe hypotension, seizures, and neuroleptic malignant syndrome.

As the management of cyclobenzaprine overdose is complex and ever-changing, it is recommended that a poison control center be consulted prior to treatment. Typical management involves gastrointestinal decontamination, close cardiac monitoring, and monitoring for signs of CNS or respiratory depression. As cyclobenzaprine exists in relatively low concentrations in plasma, monitoring of drug plasma levels should not guide management and dialysis is likely of no value.

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.

Because of its atropine-like action, Cyclobenzaprine Hydrochloride should be used with caution in patients with a history of urinary retention, angle-closure glaucoma, increased intraocular pressure, and in patients taking anticholinergic medication.

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.

Plasma concentration may be increased with the use of cimetidine, diltiazem, disulfiram, methylphenidate, ritonavir, and verapamil. Side-effects are increased by adrenaline, amiodarone, general anesthetics, SSRIs, antihistamines, antimuscarinics, antipsychotics, anxiolytics and hypnotics, clozapine, disopyramide, diuretics, flecainide, MAOIs, moclobemide, moxifloxacin, nefopam, nicorandil, noradrenaline, phenothiazine, pimozide, procainamide, propafenone, quinidine, selegiline, sibutramine, sotalol, terfenadine, thioridazine, and tramadol. Effects of adrenergic neurone blockers, clonidine, barbiturates, nitrates, and primidone are reduced while effects of baclofen, opioid analgesics, and thyroid hormones are enhanced with concomitant use of cyclobenzaprine. Carbamazepine and rifampicin may increase metabolism of cyclobenzaprine. Effects may be antagonized by oestrogens. Avoid use with brimonidine, entacapone, artemether with lumefantrine, or sibutramine. CNS effects may be enhanced by other CNS depressants.

Volume of Distribution

The volume of distribution is approximately 25 L .

The volume of distribution of cyclobenzaprine is approximately 146 L. The combination of high plasma clearance despite a relatively long half-life observed with cyclobenzaprine is suggestive of extensive tissue distribution.

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 .

The oral bioavailability of cyclobenzaprine has been estimated to be between 0.33 and 0.55. C_max is between 5-35 ng/mL and is achieved after 4 hours (T_max). AUC over an 8 hour dosing interval was reported to be approximately 177 ng.hr/mL.

Half Life

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

The effective half-life of cyclobenzaprine in young healthy subjects is approximately 18 hours. These values are extended in the elderly and those with hepatic insufficiency, with a mean effective half-life of 33.4 hours and 46.2 hours in these groups, respectively.

Clearance

The mean clearance rate is approximately 5 L/h .

The approximate plasma clearance of cyclobenzaprine is 0.7 L/min.

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 .

After administration of a radio-labeled dose of cyclobenzaprine, 38-51% of radioactivity was excreted in the urine while 14-15% was excreted in the feces. Cyclobenzaprine is highly metabolized, with only approximately 1% of this same radio-labeled dose recovered in the urine as unchanged drug. Metabolites excreted in the urine are likely water-soluble glucuronide conjugates.

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.

Pregnancy: Pregnancy category B. This drug should be used during pregnancy only if clearly needed.

Lactation: Caution should be exercised when Cyclobenzaprine Hydrochloride is administered to a nursing mother.

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.

Recent MI, arrhythmias, severe liver disease.

Special Warning

Dose in hepatic impairment: Cyclobenzaprine should be used with caution in subjects with mild hepatic impairment starting with the 5 mg dose and titrating slowly upward. The use of Cyclobenzaprine in subjects with moderate to severe impairment is not recommended.

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.

Although rare, deaths may occur from over dosage with Cyclobenzaprine Hydrochloride. Signs and symptoms of toxicity may develop rapidly after Cyclobenzaprine overdose; therefore, hospital monitoring is required as soon as possible.

Storage Condition

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

Innovators Monograph

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