Effects of propranolol on fear of dental extraction: study protocol for a randomized controlled trial

Propranolol versus Other Selected Drugs in the Treatment of Various Types of Anxiety or Stress, with Particular Reference to Stage Fright and Post-Traumatic Stress Disorder

Propranolol, a non-cardioselective β_1,2 blocker, is most commonly recognised for its application in the therapy of various cardiovascular conditions, such as hypertension, coronary artery disease, and tachyarrhythmias. However, due to its ability to cross the blood–brain barrier and affinity towards multiple macromolecules, not only adrenoreceptors, it has also found application in other fields. For example, it is one of the very few medications successfully applied in the treatment of stage fright. This review focuses on the application of propranolol in the treatment of various types of anxiety and stress, with particular reference to stage fright and post-traumatic stress disorder (PTSD). Both mechanisms of action as well as comparison with other therapies are presented. As those indications for propranolol are, in most countries, considered off-label, this review aims to gather information that can be useful while making a decision about the choice of propranolol as a drug in the treatment of those mental conditions.

Perioperative Propranolol Against Dental Anxiety: A Randomized Controlled Trial

BACKGROUND

Promising results from a trauma reactivation study on post-traumatic stress disorder suggest that propranolol is capable of attenuating symptoms of traumatically induced mental disorders by blocking memory reconsolidation.

METHODS

A randomized, parallel, placebo-controlled, quadruple-blind trial was designed to determine the effectiveness of perioperative propranolol during exposure to dental extractions in reducing dental anxiety in patients with dental anxiety or dental phobia. Between November 2014 and December 2018, 52 patients with high levels of fear in anticipation of dental extractions who were referred to a department of oral and maxillofacial surgery for at least two tooth and/or molar removals with 1 month in between were included. On the first visit participants received either 120 mg of perioperative oral propranolol (n = 19) or placebo (n = 17), and a core fear memory was reactivated 1 h preoperatively. The primary outcome was change in severity of dental anxiety from baseline to 1-month follow-up, as indexed by the short version of the dental anxiety inventory (S-DAI). Secondary outcome measures were change in intra-operative state anxiety and specific phobia diagnoses.

RESULTS

Linear mixed model (LMM) yielded no statistically significant difference in change of dental trait anxiety from baseline to 1-month follow-up between propranolol and placebo groups (Cohen's d = 0.23). S-DAI scores decreased in both study arms from baseline to follow-up (propranolol arm: from 32.1 [SD = 7.3] to 29.1 [SD = 8.8]; placebo arm: from 31.6 [SD = 7.5] to 27.1 [SD = 6.5]). Also, administering propranolol was not associated with a significant difference in change of intra-operative state anxiety or phobia diagnoses between groups over time.

CONCLUSIONS

The results do not concur with earlier findings regarding post-traumatic stress disorder, and suggest that individuals with traumatically induced fears or phobias do not benefit from the application of perioperative propranolol.

Comparison of dexmedetomidine with midazolam for dental surgery: A systematic review and meta-analysis

INTRODUCTION

Dexmedetomidine and midazolam have become important approaches for the sedation of dental surgery. However, the comparison of these 2 drugs for the sedation of dental surgery has not been well established. We conduct a systematic review and meta-analysis to evaluate the efficacy of dexmedetomidine versus midazolam for dental surgery.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials are searched. Randomized controlled trials (RCTs) assessing the influence of dexmedetomidine versus midazolam on dental surgery are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. Meta-analysis is performed using the random-effect model.

RESULTS

Five RCTs and 420 patients are included in the meta-analysis. Compared with midazolam intervention for dental surgery, dexmedetomidine intervention has similar lowest SpO2, lowest heart rate and lowest systolic blood pressure, duration of surgery, and total volume of local anesthetic, but is associated with stable and reduced lowest diastolic blood pressure.

CONCLUSIONS

Similar benefits of dexmedetomidine and midazolam intervention are observed for the sedation of dental surgery in terms of SpO2, heart rate, systolic blood pressure, and the volume of local anesthetic, but dexmedetomidine may result in more stable diastolic blood pressure.

Reconsolidation and psychopathology: Moving towards reconsolidation-based treatments

Interfering with memory reconsolidation has valuable potential to be used as a treatment for maladaptive memories and psychiatric disorders. Numerous studies suggest that reconsolidation-based therapies may benefit psychiatric populations, but much remains unanswered. After reviewing the literature in clinical and healthy human populations, we discuss some of the major limitations to reconsolidation studies and clinical application. Finally, we provide recommendations for developing improved reconsolidation-based treatments, namely exploiting known boundary conditions and focusing on a novel unconditioned stimulus-retrieval paradigm.