Reversing the Effects of 0.5% Bupivacaine Using Phentolamine Mesylate: A Preliminary Randomized Controlled Clinical Trial

EFFECTIVENESS OF PHENTOLAMINE MESYLATE IN REVERSAL OF LOCAL ANESTHESIA: SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

The aim of the present paper is to summarize the effectiveness of Phentolamine mesylate on the reversal of local anesthesia (LA).

METHODOLOGY

Seven electronic databases were searched for randomized clinical trials in patients who received LA (population) and either received a Phentolamine injection (intervention) after LA compared to placebo or sham (control) to cause a return of normal sensation (outcome). Risk of bias assessment was performed using Cochrane risk of bias assessment tool 2.0. The hazard ratio (HR) was calculated as the event (time to return to the normal sensation) was a time-dependent event, as well as the weighted mean difference (WMD), was computed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was used to assess the certainty of the evidence.

RESULTS

Ten studies met our inclusion criteria and were included in this review. After pooling the results quantitatively, the value of the HR in the tongue was 0.56 (95% CI: 0.41-0.75, P<.001); in lower lip, the value was 0.56 (95% CI: 0.38-0.83, P = .004) and for upper lip, the value was 0.50 (95% CI: 0.31-0.80, P = .004). The WMD for the time to return for normal sensation was -47.71 min for the tongue (95% CI: -73.63 to -21.80 min, P<.001), -73.29 min for lower lip (95% CI: -88.41 to -58.16 min, P<.001) and -86.86 min for upper lip (95% CI: -101.16 to -72.57 min, P<.001). There is a high certainty of evidence that patients who have been administered local anesthesia may achieve faster recovery of normal sensation in tongue, and moderate certainty of evidence for return of normal sensation in lower lip and upper lip, if Phentolamine was administered after the local anesthesia. The adverse effects were reported in a few studies and were minor, not necessitating any medical intervention.

CONCLUSIONS

Phentolamine might be a useful adjunct in patients who desire an earlier return of normal sensation and function after local anesthesia. Future research should be directed to study the cost-effectiveness or dental patient-reported outcomes of Phentolamine after local anesthetic injections.

Use of Phentolamine Mesylate in Implant Surgery: Analysis of Adverse Effects and Haemodynamic Changes

The clinical application of phentolamine mesylate (PM) as an anaesthetic reversal agent has been documented in the paediatric population and in conservative dentistry, but no studies have been conducted regarding dental implant surgery. A prospective randomised study was conducted on 60 patients eligible for mandibular implant treatment, randomly divided between a control group (CG) and an experimental group (EG), to whom PM was administered. Haemodynamic changes, adverse effects and patient satisfaction were assessed. No statistically significant differences in haemodynamic changes and postoperative pain were found between CG and EG (p < 0.05), except for systolic blood pressure (SBP), which increased slightly in EG, without posing a risk to patients. There were no differences in the occurrence of adverse effects between the two groups, except for greater difficulty in chewing and biting (p < 0.05) in CG and greater pain in the injection area (p = 0.043) in EG. Among EG patients, 83.3% reported that they would request PM again for future dental treatment. The use of PM offers an alternative to implant surgery, thereby increasing patients' quality of life without increasing the risks.

Efficacy of phentolamine mesylate in reducing the duration of various local anesthetics

Background

To evaluate changes in the effectiveness of phentolamine mesylate in combination with different local anesthetics (LAs) and vasoconstrictors. A prospective randomized double-blind study was conducted with 90 patients divided into three groups, with each group being administered one of three different LAs: lidocaine 2% 1/80,000, articaine 4% 1/200,000, and bupivacaine 0.5% 1/200,000.

Methods

We compared treatments administered to the mandible involving a LA blockade of the inferior alveolar nerve. Results were assessed by evaluating reduction in total duration of anesthesia, self-reported patient comfort using the visual analog pain scale, incidence rates of the most common adverse effects, overall patient satisfaction, and patient feedback.

Results

The differences among the three groups were highly significant (P < 0.001); time under anesthesia was especially reduced for both the lip and tongue with bupivacaine. The following adverse effects were reported: pain at the site of the anesthetic injection (11.1%), headaches (6.7%), tachycardia (1.1%), and heavy bleeding after treatment (3.3%). The patients' feedback and satisfaction ratings were 100% and 98.9%, respectively.

Conclusions

Efficient reversal of LAs is useful in dentistry as it allows patients to return to normal life more readily and avoid common self-injuries sometimes caused by anesthesia. Phentolamine mesylate reduced the duration of anesthesia in the three studied groups, with the highest reduction reported in the bupivacaine group (from 460 min to 230 min for the lip and 270 min for the tongue [P < 0.001]).

The success of using 2% lidocaine in pain removal during extraction of mandibular premolars: a prospective clinical study

BACKGROUND

The purpose of this study was to evaluate the anesthetic effectiveness of a buccal infiltration technique combined with local massage (using 2% lidocaine) in the extraction of mandibular premolars to be utilized as an alternative to the conventional inferior alveolar nerve block.

METHODS

Patients eligible included any subject with a clinical indication for tooth extraction of the mandibular 1st or 2nd premolars. All patients were anesthetized buccally by local infiltration technique followed by an external pressure applied for 1 min directly over the injection area. In each case, another local injection was given lingually. All operations were started at approximately 5 min after the buccal injection. The collected data included age, gender, pain perception and its intensity during treatment at three checkpoints, apical tenderness, and the type of extraction. Any associated complications or difficulties were also recorded. Then the results were analyzed and interpreted using appropriate statistical tests. The significance level was set at P ≤ 0.05.

RESULTS

A total of 247 cases (1st premolar, n = 119; 2nd premolar, n = 128), predominantly male, were included. In 95% of study sample, the patients were satisfied with the dental extraction without any pain. However, in 5% of cases, pain was reported at the stage of tooth removal. Apical tenderness was found to be present in 11% of the total cases. Three teeth required surgical removal. Upon analysis, no significant differences in the success rates were detected between the 2 premolar groups or amongst the various age groups. Minor and transient side effects were reported in this study.

CONCLUSION

The technique is simple and effective as well. It might be considered as an alternative anesthetic injection to the inferior alveolar nerve block for dental extraction of the mandibular premolars.