Voltaren is a medicine used in the treatment of inflammatory conditions such as arthritis and ankylosing spondylitis. The active ingredient of the medicine - diclofenac sodium - works by inhibiting the synthesis of prostaglandins, substances which are directly implicated in the inflammatory response. Common side effects include diarrhoea, constipation and headache.Voltaren is a benzene acetic acid derivative. Voltaren is available as delayed-release tablets of 75 mg for oral administration. The inactive ingredients in Voltaren include hydroxypropyl methylcellulose, methacrylic acid copolymer, iron oxide, lactose, microcrystalline cellulose, magnesium stearate, polyethylene glycol, povidone, propylene glycol, sodium hydroxide, sodium starch glycolate, talc, titanium dioxide. Voltaren is used in relieving pain, swelling, and joint stiffness caused by arthritis. Decreasing these symptoms helps you do more of your normal daily activities. Voltaren is used in the treatment of mild to moderate pain or signs and symptoms of rheumatoid arthritis or osteoarthritis. Voltaren is a nonsteroidal anti-inflammatory drug that works by reducing substances in the body that cause pain and inflammation.