Rhinology 2013; 51: 236-242

Agius AM¹, Muscat R², Jones NS³

1. The Medical School, University of Malta, Msida, Malta
2. Department of Physiology and Biochemistry, University of Malta
3. Department of Otolaryngology, University of Nottingham, United Kingdom

Summary

Patients often present with chronic facial pain despite normal nasal endoscopy and sinus computerized tomography. Such pain has increasingly been recognized as being of neurological origin with one of the commonest underlying causes being mid-facial segmental tension-type pain (MFP) which is a version of tension headache in the face. Descending serotonergic neuronal projections are known to modulate pain and intra-platelet serotonin levels are an accepted model reflecting central intra-neuronal serotonin.

Objectives

Primary Outcome Measures:  1.To determine whether low-dose amitriptyline significantly changes whole blood serotonin compared to a surrogate placebo in patients with chronic MFP  2. To determine whether the addition of pindolol, a beta blocker with serotonin receptor blocking properties further alters blood serotonin.

Setting:  An Otolaryngological practice on a Mediterranean island.

Study Design  Randomised single-blind study with parallel design

Method: Sixty-two patients were randomized to three treatment groups (a) amitriptyline 10mg daily (b) amitriptyline 10mg daily with pindolol 5mg twice daily and (c) loratadine 10mg daily as surrogate placebo. Whole blood serotonin was taken before and after 8 weeks of treatment.

Results: There was a significant reduction in blood serotonin levels in the amitriptyline with pindolol group. A non-significant reduction was seen in the amitriptyline group, with no change in serotonin levels in the surrogate placebo group. A comparison of change in serotonin with change in pain frequency and intensity scores is presented.

Conclusion: When linked to the clinical response this study provides evidence that the serotonergic system is involved in the modulation of chronic MFP.