Relaxid Mr

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.

Thiocolchicoside is a semi-synthetic colchicine derivative used as an analgesic and anti-inflammatory.

Thiocolchicoside is a skeletal muscle-relaxant drug used in the treatment of orthopedic, traumatic and rheumatologic disorders . It is indicated as an adjuvant drug in the treatment of painful muscle contractures and is indicated in acute spinal pathology, for adults and adolescents 16 years of age and older . Recent studies have examined its effect on muscle tone, stiffness, contractures, and soreness experienced by athletes during sporting competitions .

Relaxid Mr is also used to associated treatment for these conditions: Ankylosing Spondylitis (AS), Osteoarthritis (OA), Rheumatoid ArthritisBack Pain, Acute, Chronic Back Pain, Extra-Articular Rheumatism, Muscle Inflammation, Muscle Spasms, Musculoskeletal Pain, Nonspecific Pain Post Traumatic Injury, Osteoarthritis (OA), Pain, Post Surgical Pain, Post-traumatic pain, Postoperative pain, Rheumatoid Arthritis, Soreness, Muscle, Spasms, Spinal pain, Vertebral column pain, Inflammation localized, Localized pain, Mild to moderate pain, Musculoskeletal spasms

How Relaxid Mr 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 .

Thiocolchicoside, is a synthetic sulfur derivative of colchicoside, a naturally occurring glucoside contained in the Colchicum autumnale plant. Thiocolchicoside has a selective and potent affinity for g-aminobutyric acid A (GABA-A) receptors and acts on muscular contractures by activating the GABA inhibitory pathways thereby behaving as a potent muscle relaxant . Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the human cortex . GABAergic neurons are involved in myorelaxation, anxiolytic treatment, sedation, and anesthetics. GABA can also modulate heart rate and blood pressure.

It also has an affinity for the inhibitory glycine receptors (i.e., have glycomimetic and GABA mimetic activity), therefore acts as a muscle relaxant. Glycine is an inhibitory neurotransmitter and acts as an allosteric regulator of NMDA (N-methyl-D-aspartate) receptors. It is involved in the processing of motor and sensory data, thereby regulating movement, vision, and audition. Inhibitory neurotransmitter in spinal cord, allosteric regulator of NMDA receptors .

In one study, thiocolchicoside inhibited the function of recombinant human strychnine-sensitive glycine receptors composed of the alpha1 subunit with a potency (median inhibitory concentration of 47 microM) lower than that apparent with recombinant GABA(A) receptors. The drug also inhibited the function of human nicotinic acetylcholine receptors made of the alpha4 and beta2 subunits, however, this effect was partial and moreover only apparent at high concentrations. Thiocolchicoside demonstrated no effect on the function of 5-HT(3A) serotonin receptors .

Dosage

Relaxid Mr 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 .

Has been shown to cause chromosomal aneuploidy and male infertility. Should be avoided during all stages of pregnancy, lactation and puberty. Is a potential risk factor for cancer.

In 2013, The European Medical Association (EMA) mandated that the use of thiocolchicoside-containing medicines by mouth or injection should be restricted across the European Union (EU). These drugs are now recommended only as an add-on treatment for painful muscle contractures resulting from spinal conditions in adults and adolescents 16 years old and older. Additionally, the dose of thiocolchicoside by mouth or injection should be limited. This is due to experimental evidence suggesting that thiocolchicoside was metabolized into M2 or SL59.0955, that has the propensity to damage dividing cells, resulting in aneuploidy (an abnormal number or arrangement of chromosomes). As a result, the CHMP (committee for medicinal products for human use) examined the safety profile of this medicine and consider what regulatory action might be appropriate .

The CHMP reviewed the evidence, with consideration of opinions from experts in medicines safety, and concluded that aneuploidy may occur with M2 at levels not significantly greater than those measured after recommended doses of thiocolchicoside ingested orally. Aneuploidy is a strong risk factor for fetal harm, decreased fertility in men, and could theoretically increase the risk of developing cancer .

The maximum recommended oral dose is 8 mg every 12 hours; treatment length should not exceed 7 consecutive days. When given intramuscularly (IM), the maximum dose is 4 mg every 12 hours, for a maximum of 5 days .

In addition to the above toxicity, a study was done on the hepatotoxic potential of thiocolchicoside. It was observed that serum AST and ALT levels increased following of the administration oral thiocolchicoside at 8 mg/day. Two weeks after discontinuing thiocolchicoside therapy, liver enzymes had decreased to levels within the normal range. Although infrequent, thiocolchicoside should be considered a rare hepatotoxic agent in clinical practice .

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 .

The apparent volume of distribution of thiocolchicoside is estimated to be approximately 42.7 L after an intramuscular injection of 8 mg .

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 .

Oral bioavailability is ~25% After intramuscular administration, thiocolchicoside Cmax occur in 30 min and .reach values of 113 ng/mL after a 4 mg dose and 175 ng/mL after a 8 mg dose. The corresponding values of AUC are respectively 283 and 417 ng.h/mL. The pharmacologically active metabolite SL18.0740 is found at lower concentrations with a Cmax of 11.7 ng/mL occurring 5 h post administration and an AUC of 83 ng.h/mL .

After oral administration, no thiocolchicoside is detected in plasma. Only two metabolites are observed: The pharmacologically active metabolite SL18.0740 and an inactive metabolite SL59.0955. For both metabolites, maximum plasma concentrations occur 1hour after thiocolchicoside administration. After a single oral dose of 8 mg of thiocolchicoside the Cmax and AUC of SL18.0740 are about 60 ng/mL and 130 ng.h/mL respectively. For SL59.0955 these values are much lower: Cmax around 13 ng/mL and AUC ranging from 15.5 ng.h/mL (until 3h) to 39.7 ng.h/mL (until 24h) .

Half Life

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

Approximately 7.7h .

Clearance

The mean clearance rate is approximately 5 L/h .

Primarily extrarenal elimination (75% of the total body clearance) .

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 .

Thiocolchicoside is not eliminated unchanged, rather as one of three metabolites found in either feces (~79 %) or in urine 20%. 3- demethylcolchicine (M2) and 3-O-glucurono-demethylcolchicine (M1) are found in both urine and feces, where as di-demethylcolchicine is found only in feces .

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.

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