The lower back is the part of the back between the bottom of the ribs and the top of the legs. Low back pain is the most common of back pain. In most cases, it is not due to a serious disease or serious back problem, and the exact cause of the pain is not clear. This is called nonspecific lower back pain. When the pain lasts up to one month, this is known as acute low back pain. Sometimes the pain may develop immediately after lifting something heavy, or after an awkward twisting movement, or it can develop for no apparent reason. The severity of the pain can range from mild to severe. General symptoms of low back pain include: dull aching pain that travels to the buttocks, legs and feet, pain that is worse after prolonged sitting, pain that feels better when changing positions and pain that is worse after waking up and better after moving.
Tizanidine as an intranasal spray is being developed as a new treatment option for patients with acute low back pain. It works by blocking pain sensations that are sent to the brain, temporarily relaxing muscle tone. Tizanidine is already available in the tablet form as a short-acting muscle relaxer used to relieve the stiffness and restriction of muscles due to injuries or diseases of the spinal cord. If licensed, tizanidine prepared for intranasal administration will offer an alternative to the oral administration for patients with acute low back pain when short term dosing and a fast effect is desired.
Mexiletine is under registration in Europe for the symptomatic treatment of myotonic disorders. It is administered as an oral capsule and it exerts its action by reducing the rate of contraction in the heart and other muscles. Currently it is used unlicensed in the UK, meaning that it is not currently approved but some healthcare providers consider it to be potentially beneficial based on research or professional experience. There are currently no licensed treatment options available to treat symptoms of myotonia, therefore, if licensed, mexiletine will offer access to an approved treatment option.