A study published in “Cephalalgia” portrayed propranolol to be more effective in minimizing temporomandibular disorder pain among migraineurs compared to non-migraineurs, with more of the effect mediated by minimized heart rate compared to by minimized headache impact. Inna E Tchivileva et al. undertook this placebo-controlled, multi-site, parallel-group, double-blind trial study (SOPPRANO) to explore the pain-relieving efficacy of propranolol in individuals suffering from the  painful chronic myofascial temporomandibular disorder. 

In this randomized controlled phase 2b analysis, the recruited participants were given propranolol or placebo for nine weeks. Alteration in the facial pain index derived from daily symptom diaries was the major outcome. Linear and logistic regression models were assessed for a migraine × treatment-arm interaction in alleviating facial pain index. The counterfactual models investigated alterations in headache impact and heart rate as mediators of the efficacy of propranolol.

It was noted that the efficacy of propranolol in minimizing facial pain index was higher among the 104 migraine subjects vs. the 95 non-migraine subjects. For the binary ≥ 30% decline in facial pain index, the odds ratios were 3.3  versus 1.3 respectively, although the interaction was statistically non-significant. The cumulative response curves validated higher efficacy for migraine patients compared to patients without migraine (differences in area under the curve 26% and 6%, respectively).

As per the causal mediation analysis, propranolol's efficacy in decreasing temporomandibular disorder  pain was not mediated by decreased headache impact, but by propranolol’s effect on heart rate. While 9% of the therapeutic effect was mediated by minimized headache impact, about 46% was mediated by minimized heart rate.

Thus, propranolol seems to be the drug of choice for managing painful temporomandibular disorder in migraineurs.