New pain relief for dental work goes up your nose

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A Phase 3 clinical trial has deemed a nasal spray called Kovanaze safe and effective for avoiding pain at the dentist—including the sting of a numbing injection.

“There is really nothing else like this out there.”

“There is really nothing else like this out there,” says Elliot V. Hersh, the study’s lead author and a professor in the department of oral and maxillofacial surgery/pharmacology at the University of Pennsylvania School of Dental Medicine. “This is obviously a great thing for needle-phobic individuals, and it can reduce inadvertent needle-stick injuries in the clinic as well.”

The double-blind, randomized trial found that the compound, a combination of the local anesthetic tetracaine and the nasal decongestant oxymetazoline, was effective at preventing pain during a single restorative procedure in an upper bicuspid, canine, or incisor in 88 percent of patients, a rate comparable to the success of commonly used injectable numbing agents. The most common side effects were runny nose and nasal congestion; no serious side effects were reported.

St. Renatus developed Kovanaze, which received FDA approval on June 29.

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The idea for Kovanaze, or K305, emerged when St. Renatus co-founder Mark Kollar was hit in the chin playing basketball, requiring 21 stitches. A fellow player happened to be an ear nose and throat specialist, who placed the sutures and also diagnosed Kollar with a deviated nasal septum. The ENT performed the septum repair and, when Kollar returned to his office for a follow-up visit, gave him a nasal spray containing tetracaine to remove a nasal stent.

Once the stent was removed, Kollar noticed his teeth were numb. The ENT said a few other patients had reported the same sensation. Kollar, who happened to be a practicing dentist, went to his office to test his teeth with a dental electronic pulp stimulator and found that they were indeed numb.

The trial recruited 150 adults who passed a health screening and were set to undergo a single dental filling in an upper bicuspid, canine, or incisor. One hundred patients were assigned Kovanaze and 50 were assigned a placebo.

Patients received one spray, waited four minutes, received a second spray, waited 10 minutes, and then a test drilling was performed. If the patients experienced pain at that point, they received a third spray. Patients who still experienced pain at that point received a rescue injection of local anesthetic to complete the procedure. Patients’ heart rate and blood pressure were recorded at various times throughout the visit.

Eighty-eight percent of the people who received Kovanaze were able to have the dental restorative procedure completed without a rescue injection, compared to 28 percent for the placebo vehicle spray.

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Before receiving the spray, all patients were given what’s known as an alcohol sniff test to measure baseline sense of smell. Repeating the test just after the procedure and again a day later, the researchers found that the drug caused minimal changes in olfaction.

The K305 treatment had a small effect on blood pressure, causing it to rise slightly. Some patients reported nasal congestion, nasal discomfort, throat pain and irritation, headache, and eye watering, but no serious adverse events were reported.

To follow up on the study, Hersh says the company will likely pursue additional investigations to see if more intensive dental procedures can be performed using this anesthetic, such as root canals or oral tissue biopsies. It’s likely that further studies will also evaluate whether the drug can be safely administered to children. Currently the FDA has approved the drug for use only in individuals weighing at least 40 kilograms, roughly 88 pounds.

“It would certainly make for a more stress-free dental office visit for children as well as adults if we could replace some of these anesthetic injections with a simple spray,” Hersh says. “It may also keep some children out of the operating room, which would be a major cost savings to the child’s family and reduce potential morbidity associated with general anesthetic procedures.”

A grant from St. Renatus supported the research. The results appear in the Journal of the American Dental Association.

Source: University of Pennsylvania