Description
It is a pain reliever prescribed to treat a wide variety of conditions. The combination of medications makes it useful for relieving inflammation, relaxing muscle, and reducing both fevers and pains. It is commonly used to patients suffering from severe headaches, arthritis, swelling or skeletal muscle injuries. Given the multiple pathways involved in body’s perception of pain, a combination therapy is well suited for pain management. Diclofenac acts by attenuation of peripheral prostaglandin synthesis(primarily) and has marked anti-inflammatory properties. Paracetamol acts centrally and inhibits brain prostaglandin synthesis which may partly account for its well documented activity to reduce fever and to induce analgesia. Chlorzoxazone being a centrally acting muscle relaxant, relieves muscular spasms. The combination exerts a better pain control due to action on different pathways of pain.
Pharmacology
- Pharmacokinetics
- Diclofenac Sodium
- Absorption: – Diclofenac is NSAIDs with anti-inflammatory, analgesic and antipyretic properties. It is rapidly and almost completely absorbed when administered as an oral dose. Food does not have a significant effect on the extent of oral absorption.
- Protein Binding: -At therapeutic concentrations it is more than 99% bound to plasma proteins.
- Metabolism: -Diclofenac and/or its metabolites are rapidly and preferentially taken up and retained in inflamed tissues. It penetrates synovial fluid where concentrations may persist even when plasma concentrations fall.
- Half-Life: – The terminal half-life is about 1 to 2 hours. Diclofenac acts by inhibiting cyclooxygenase, thus prevents the formation of prostaglandins, the mediators of inflammation. It also inhibits lipoxygenase thus preventing the synthesis of leukotrienes. Thus it acts on both the pathways and is a very potent anti-inflammatory drug/ medicine.
- Paracetamol:
- Absorption: Paracetamol is rapidly and completely absorbed after oral administration.
- Distribution: It is distributed mostly in the body in unbound form.
- Metabolism: It is extensively metabolised in the liver.
- Excretion: Excreted in the urine.
- Chlorzoxazone:
- Absorption- Rapidly and completely absorbed after oral administration.
- Distribution- Widely distributed in the body.
- Metabolism- It is metabolized in the liver to its metabolites by glucoronide conjugation.
- Excretion- It is excreted through urine.
- Pharmacodynamics
- Diclofenac Sodium: – Diclofenac possess analgesic, anti-inflammatory and antipyretic action. It inhibits the enzyme cyclo-oxygenase and there by inhibits the synthesis of Prostaglandins (PGs). It is more potent against cyclo-oxygenase-2 enzyme as compared to other NSAIDs like Indomethacin, Naproxen etc. It reduces intracellular concentrations of free arachidonic acid in leukocyte by altering its release or uptake.
- Paracetamol: – Paracetamol has analgesic and antipyretic action.
It is more active on cyclo-oxygenase enzyme in brain. Peripherally it is a poor inhibitor of prostaglandin synthesis.
Analgesic action: Paracetamol raises the pain threshold and produces analgesic effect.
Antipyretic action: Paracetamol lowers fever by direct action on the thermoregulatory centre in the Hypothalamus and block the effects of endogenous pyrogen.
- Chlorzoxazone: –This muscle relaxant works by blocking nerve impulses (or pain sensations) that are sent to your brain. It inhibits degranulation of mast cells, subsequently preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), mediators of type I allergic reactions. It may also reduce the release of inflammatory leukotrienes. Chlorzoxazone may act by inhibiting calcium influx.
Indications: –
- Soft tissue injuries with spasm and inflammation,
- Neck / shoulder / back pain,
- Tendonitis / tenosynovitis / bursitis
- Musculoskeletal disorders
