Local Anesthetic Effect of Amitriptyline versus Lidocaine in Isolated Lesion of the Limb Requiring Primary Suturing; Assessing a Novel Therapeutic Agent

Anesthetic Effect of 2% Amitriptyline Versus 2% Lidocaine: A Comparative Evaluation

Introduction A common dental problem is the fear of pain during needle prick for giving local anesthesia (LA). The needle prick pain during dental procedures often varies with sex and age. Perception of pain depends on various factors, which can be psychological and biological. This perception of pain may change the behavior of patients toward dental treatments. Traditionally, lidocaine gel formulation was utilized before the parenteral dosage form. The lidocaine gel formulation is considered the drug of choice for LA in dental surgery. Currently, amitriptyline has been utilized in dental practice because of its beneficial pharmacology. Hence, the present study has been undertaken to compare the anesthetic ability of amitriptyline as an intraoral topical anesthetic agent with lidocaine gel. Methods This study was a comparative clinical study between two medications' anesthetic properties. This study included 120 patients indicated for bilateral orthodontics (the subdivision of dentistry that emphasizes identifying necessary interventions for the malocclusion of teeth) procedures. All the subjects were divided into amitriptyline and lidocaine groups. Both anesthetic gels were applied at separate sites before the injection of LA. The time of the onset of anesthesia was noted and analyzed. Patients were selected on the basis of inclusion and exclusion criteria. Individuals aged 18 to 30 years who were systemically healthy and orthodontically indicated for bilateral premolar extraction were included in this study. Again, patients with a history of neurological disorders and allergies to amitriptyline and lidocaine were excluded from the current study. Results Significant differences emerged between groups at five and 10 minutes, with amitriptyline-induced partial numbness (36.7% and 6.7%). At 40 and 45 minutes, both groups showed varied partial and complete numbness, with amitriptyline leading to partial recovery (23.3% and 73.3% complete numbness, 23.3% partial recovery) and lidocaine resulting in partial recovery (81.7%). When comparing the visual analog scale (VAS) scores, both groups exhibited a similar simultaneous effect at 15 minutes. Nonetheless, amitriptyline displayed significantly lower scores at 25 and 35 minutes (p < 0.001) in comparison to lidocaine. Similar observations were made when controlling for pain intensity. Conclusion It was concluded that amitriptyline holds both anesthetic and analgesic properties. Nevertheless, this study was unable to generalize the study findings because of the small sample size and being a single-center study. However, the VAS scores of anesthetic and analgesic pharmacodynamics properties of amitriptyline were statistically significantly lower than lidocaine, particularly at 25 and 35 minutes. Additionally, amitriptyline-induced anesthetic and analgesic pharmacology, especially pharmacokinetics properties, depends on the location and pattern of pain.

Dissolution mechanism of supported phospholipid bilayer in the presence of amphiphilic drug investigated by neutron reflectometry and quartz crystal microbalance with dissipation monitoring

The influence and interaction of the ionizable amphiphilic drug amitriptyline hydrochloride (AMT) on a 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) phospholipid bilayer supported on a silica surface have been investigated using a combination of neutron reflectometry and quartz crystal microbalance with dissipation monitoring. Adding AMT solutions with concentrations 3, 12, and 50 mM leaves the lipid bilayer mainly intact and we observe most of the AMT molecules attached to the head-group region of the outer bilayer leaflet. Virtually no AMT penetrates into the hydrophilic head-group region of the inner leaflet close to the silica surface. By adding 200 mM AMT solution, the lipid bilayer dissolved entirely, indicating a threshold concentration for the solubilization of the bilayer by AMT. The observed threshold concentration is consistent with the observation that various bilayer structures abruptly transform into mixed AMT-DOPC micelles beyond a certain AMT-DOPC composition. Based on our experimental observations, we suggest that the penetration of drug into the phospholipid bilayer, and subsequent solubilization of the membrane, follows a two-step mechanism with the outer leaflet being removed prior to the inner leaflet.

Effects of Topical Sesame Oil Extracted from Tahini (Ardeh) on Pain Severity in Trauma Patients: A Randomized Double-Blinded Placebo-Controlled Clinical Trial

Objective

To investigate the effects of sesame oil extracted from tahini (Ardeh) on pain severity in patients with upper or lower limbs trauma.

Methods

This double-blinded randomized clinical trial study was conducted on 120 patients with upper or lower trauma in Shahid Rajaee Hospital, Shiraz, Iran, from May the 1^st through November 30^th, 2016. The patients were randomly assigned to two groups using block randomization. The intervention group received topical sesame oil extracted from tahini (Ardeh) and the placebo group received cooking oil. Pain severity, pain sensitivity and heaviness of painful site were assessed.

Results

Overall, we included 90 patients with traumatic limb injuries in this study who were randomized to two study groups. The mean age of the patients was 28.3 ± 6.8 (ranging from 25 to 35) years and there were 63 (70%) men and 27 (30%) women among the patients. In the sesame oil group, the mean changes in the pain severity (-1.53 ± 0.57, P<0.001), pain sensitivity (-1.45 ± 0.64, P<0.001) and heaviness of painful site (-1.56 ± 0.68, P<0.001) were significantly lower when compared to the placebo group in the second day of the intervention. None of the patients experience adverse drug effects.

Conclusion

Our findings suggest that the topical use of sesame oil extracted from Tahini has a pain reliever effect on the skin after bruising and it helps prevent skin discoloration in patients with traumatic injuries of limbs.