Intranasal lidocaine blocks orofacial pain with few behavioral side effects [presentation] Presentation uri icon
  • Objectives: Intranasal lidocaine has been demonstrated to deliver drug to the trigeminal nerve and decrease trigeminal neuralgia pain in humans. This study measured the extent of the trigeminal nerve block caused by intranasal lidocaine, and the potential side effects of intranasal lidocaine in a rat model. Methods: C-fos gene expression was used as a biomarker for neural activity in the trigeminal brainstem to identify the sites of action for intranasal lidocaine. Doses of 0, 4, and 10% lidocaine were delivered intranasally to block the inflammatory pain caused by 4% carrageenan injection into the whisker pad. Three behavior tests were used to assess the affect of intranasal lidocaine on functional neural activity at the cortex, cerebellum, and cervical spinal cord levels. Cortical function was estimated by timing the rat's fine motor skills to remove a sticker placed on its paw. Cerebellar function was analyzed using a balance beam test and cervical spinal cord function was estimated by forearm grip strength. Results: Intranasal lidocaine decreased the pain-associated biomarker c-fos in the part of the brainstem innervating the whisker pad and maxillary teeth at 4% and 10% intranasal lidocaine (p<0.01). No behavioral effect on tests for cortical, cerebellar or cervical spinal cord function after 4% intranasal lidocaine doses. By contrast, cerebellar function was significantly reduced (p<0.05) after 10% intranasal lidocaine. Treatment with 10% intranasal lidocaine did not affect the cortical or cervical spinal behavioral test responses. Conclusions: These results indicate that intranasal delivery is an effective trigeminal nerve block to the maxillary teeth and facial structures. This novel trigeminal nerve block could be effective for patients with needle phobia and dental fear/anxiety.

  • participant
  • Bereiter, D. A.   Presenter  
  • Frey II, William H., PhD   Presenter  
  • Hermes, B.   Presenter  
  • Jarnot, N.   Presenter  
  • Johnson, N. J.   Presenter  
  • Thompson, R.   Presenter  
  • Research
  • Animal Studies
  • Dental Care
  • Drugs and Drug Therapy
  • Intranasal Administration
  • Pain