Promising Drug Treatment for Trigeminal Neuralgia Could Bring New Life Quality to Patients
Trigeminal neuralgia is one of the most feared medical conditions known to men. This chronic pain disorder is characterized by recurrent episodes of lancinating pain on one side of the face. In its most violent form (typical TN), individual episodes can last seconds, minutes or even hours, occurring several times per day. In these cases, patients generally describe the pain as an electric shock and stabbing or burning sensation on the face. It is one of the most painful conditions documented in medical literature. The disorder is colloquially known as the 'suicide disease'.
Current drug-based treatments (anticonvulsants, muscle relaxants or antipsychotics) bring some relief to most patients, but at the price of potentially dangerous side effects. However, a new drug developed by researchers at the University of Zurich promises a better compromise.
Selective inhibition of sodium channels
The experimental drug called BIIB074 underwent a phase 2 trial across multiple health centers in Europe. Sixty seven trigeminal neuralgia patients were enrolled in open-label and double-blind tests over a 2-year period. Each patient took the experimental medicine orally three times a day over 21 (open-label) and 28 (double-blind) days. The new drug successfully reduced the pain to tolerable levels without bringing incapacitating or dangerous side effects to the patients.
Unlike drugs such as carbamazepine, Iamotrigine or baclofen, which can cause bizarre side effects, the new BIIB074 sodium channel 1.7 inhibitor was well-tolerated by most patients, creating relatively minor secondary symptoms in comparison. The most frequently reported side effects were headaches, dizziness, and fever.
These results were possible thanks to the way in which BIIB074 acts on the sodium channels, which are responsible for the transmission of pain signals to the brain. BIIB074 blocks the sodium channel 1.7 according to the channel's level of activity - the more active the channel is, the stronger will be the drugs hampering effect. Current drugs, in comparison, block the sodium channels without accounting for the activity level, which creates unnecessary side effects.
Sodium channels are located in nerve cell membranes. Their activation triggers the sensation of pain, the severity of which is proportional to the channels' activity level. According to the Zurich researchers, trigeminal neuralgia is believed to stem from a nerve deficiency or damage at the base of the skull. Given that local injections cannot reach this region, drugs are the first line of defense against the disorder.
New hope for TN patients
As one of the most physically painful and easily triggered chronic conditions, TN is highly-incapacitating. Victims often live in fear of the next episode, facing difficulties to perform simple tasks such as eating or performing oral hygiene. Depression rates are high among TN patients, which consist predominantly of women over the age of 50 (although TN can affect anyone). This rare disease claims approximately 1 new victim in 8000 people every year. The new drug could be the basis for the first easily manageable treatment for TN victims.