Researchers develop treatment for nerve pain affecting teeth and face
Center of Dental Medicine, UZH
ZURICH, Switzerland: Trigeminal neuralgia is characterised by sharp, lancinating pain in the tooth or facial area. The standard treatment for this chronic nerve pain can cause severe side-effects. Swiss researchers have now developed a novel substance that inhibits the pain effectively and is well tolerated by patients.
The sharp pain shoots into the face or teeth and is agonising for sufferers. Known as trigeminal neuralgia, it is one of the worst chronic nerve pains. The bouts are triggered by touch, such as shaving, putting on make-up, showering, talking and toothbrushing, or even a gust of wind. The cause is usually irritation of the trigeminal nerve, the cranial nerve responsible for the sensory innervation of the facial area, parts of the scalp, and the oral cavity.
New research could offer sufferers a glimmer of hope. Owing to a newly tested substance, the pain can be reduced to a tolerable level, as indicated by the promising results of an international study, now in the second phase, involving the Center of Dental Medicine at the University of Zurich (UZH).
Pain signals reach the brain via the activation of sodium channels in the membranes of nerve cells. The Nav1.7 sodium channel is frequently expressed in pain-conducting nerves, and higher pain intensity is linked to greater channel activity. Blocking this sodium channel, for example by a local anaesthetic, inhibits the pain. In trigeminal neuralgia, the nerve damage is presumed to be at the base of the skull. However, this region is difficult to reach by local injections and therefore requires drug treatment.
The novel substance, BIIB074, which was tested in the study, inhibits Nav1.7 state-dependently. This means that the more active this sodium channel is, the stronger the block by BIIB074. In contrast, currently available medications block Nav1.7 irrespective of the nerve activity, which commonly results in severe side-effects. “Unlike conventional drugs, which often cause tiredness and concentration problems, BIIB074 was not only effective but also very well tolerated,” explained Dr Dominik Ettlin, a dental specialist from UZH. “We will now test the new substance in a lot more subjects during the next study phase, which will reveal whether the new hope for more effective pain relief is justified,” he concluded.
The study, titled “Safety and efficacy of a Nav1.7 selective sodium channel blocker in patients with trigeminal neuralgia: A double-blind, placebo-controlled, randomised withdrawal phase 2a trial”, was published ahead of print on 16 February in theLancet Neurology journal.