The Effect of Pregabalin and Methylcobalamin Combination on the Chronic Postthoracotomy Pain Syndrome

Preparation, Characterization, and Evaluation of Cytotoxicity of Fast Dissolving Hydrogel Based Oral Thin Films Containing Pregabalin and Methylcobalamin

The oral availability of many drugs is problematic due to the pH of the stomach, enzymes, and first-pass effects through the liver. However, especially geriatric, pediatric, bedridden, or mentally handicapped patients and those with dysphagia have difficulty swallowing or chewing solid dosage forms. Oral Thin Films (OTFs) are one of the new drug delivery systems that can solve these problems. Pregabalin (PG) and Methylcobalamin (MC), which are frequently preferred for pain originating in the central nervous system, were brought together for the first time using OTF technology in this study. In this study, a quantification method for PG and MC was developed and validated simultaneously. Optimum formulations were selected with organoleptic and morphological controls, moisture absorption capacity, swelling capacity, percent elongation, foldability, pH, weight variability, thickness, disintegration time, and transparency tests on OTFs prepared by the solvent pouring method. Content uniformity, dissolution rate, determination of release kinetics, SEM, XRD, FT-IR, DSC, long-term stability, and cytotoxicity studies on the tongue epithelial cell line (SCC-9) were performed on selected OTFs. As a result, OTFs containing PG-MC, which are non-toxic, highly flexible, transparent, compatible with intraoral pH, with fast disintegration time (<30 s), and acceptable in taste and appearance, have been developed successfully.

Integrative Approaches to Minimize Peri-operative Symptoms

PURPOSE OF REVIEW

Cancer patients who require surgery often experience peri-operative symptoms, including nausea, anxiety, and pain, which can significantly impair quality of life. Here, we review the evidence for using integrative approaches to manage these peri-operative symptoms.

RECENT FINDINGS

Conventional peri-operative pharmacologic interventions, such as opiates for pain control, can lead to adverse effects such as respiratory depression, prolonged hospital course, and long-term dependence. Integrative medicine, also known as complementary and alternative medicine (CAM), has been explored as way to reduce peri-operative symptoms. Acupuncture, guided imagery, and loving-kindness meditation have all shown potential efficacy in reducing both peri-operative pain and anxiety in retrospective studies and small randomized controlled trials. Integrative medicine techniques, such as acupuncture, are a promising approach to control peri-operative symptoms without the associated adverse effects of more conventional pharmacologic interventions.

Trajectory and profile of quality of life in patients undergoing lung resection for lung cancer during hospitalization according to the EQ-5D

OBJECTIVE

To clarify the trajectory and profile of quality of life (QOL) in lung cancer patients undergoing surgery during hospitalization.

METHODS

Among prospectively enrolled 279 patients between 2015 and 2018, we used the EQ-5D-5 levels (EQ-5D-5L), which consist of a descriptive system of five dimensions and a visual analog scale (VAS) (from 0 to 100). The five dimensions are mobility, self-care, usual activities, pain/discomfort, and anxiety/depression, which are rated according to a 5-grade evaluation. QOL assessments were performed preoperatively (Pre) and on postoperative day 1/3/5/7 (D1/D3/D5/D7). To observe the trajectory of QOL, the EQ-5D VAS was used. To define the profile of QOL, we applied univariate linear regression analysis to predict EQ-5D VAS based on the five dimensions of EQ-5D as explanatory variables and to determine the rank of absolute values of the standardized coefficient of each dimension that represented strength of the effect on the EQ-5D VAS.

RESULTS

The means of VAS scores were as follows: Pre/D1/D3/D5/D7 = 79/45/58/64/71. Younger age, fewer comorbidities, and surgical indications decreased the VAS at D1. More comorbidities, advanced cancer stage, postoperative adverse events, and chest tube placements hampered restoration of the VAS. Regarding QOL profiles, anxiety/depression was the highest rank preoperatively while usual activity, but not pain/discomfort, was the highest postoperatively.

CONCLUSIONS

This is the first study to visualize the trajectory of QOL in surgical patients with lung cancer during hospitalization. This information may help improve perioperative patient care.

Synergistic interaction between haloperidol and gabapentin in a model of neuropathic nociception in rat

Preclinical studies have reported that sigma-1 receptor antagonists may have efficacy in neuropathic pain states. The sigma-1 receptor is a unique ligand-operated chaperone present in crucial areas for pain control, in both the peripheral and central nervous system. This study assesses the synergistic antihyperalgesic and antiallodynic effect of haloperidol, a sigma-1 antagonist, combined with gabapentin in rats with peripheral neuropathy. Wistar rats male were subjected to chronic constriction injury (CCI) of the sciatic nerve. The effects of systemic administration of gabapentin and the sigma-1 receptor antagonist, haloperidol, were examined at 11 days post-CCI surgery. An analysis of Surface of Synergistic Interaction was used to determine whether the combination's effects were synergistic. Twelve combinations showed various degrees of interaction in the antihyperalgesic and antiallodynic effects. In hyperalgesia, three combinations showed additive effects, four combinations showed supra-additive effects, and three combinations produced an effect limited by the maximum effect. In allodynia, five combinations showed additive effects, two combinations showed supra-additive effects, and five combinations produced antihyperalgesic effects limited by the maximum effect. These findings indicate that the administration of some specific combination of gabapentin and haloperidol can synergistically reduce nerve injury-induced allodynia and hyperalgesia. This suggests that the haloperidol-gabapentin combination can improve the antiallodynic and antihyperalgesic effects in a neuropathic pain model.

Local Administration of Methylcobalamin for Subacute Ophthalmic Herpetic Neuralgia: A Randomized, Phase III Clinical Trial

OBJECTIVES

The ophthalmic branch of the trigeminal nerve is one of the most frequently involved sites of postherpetic neuralgia. A single-center randomized controlled study was conducted to evaluate the efficacy of local methylcobalamin injection for subacute ophthalmic herpetic neuralgia (SOHN).

METHODS

One hundred and five patients with a pain score of 4 or greater were randomized to receive a combination of methylcobalamin and lidocaine via local injection (LM group, n = 35), intramuscular methylcobalamin and local lidocaine injection (IM group, n = 35), and oral methylcobalamin tablet and lidocaine local injection (OM group, n = 35) for 4 weeks. Multilevel mixed modeling was employed to examine treatment responses.

RESULTS

Pain scores were reduced in all groups, but this reduction was significantly greater in the LM group (6.7 at baseline vs. 2.8 at endpoint) when compared with systemic administration (IM group 6.8 vs. 4.9, OM group 6.7 vs. 5.1). Clinically relevant reduction of pain (>30%) was seen in 91% of patients in the LM group, a significantly greater proportion than in the systemic groups (66% IM group, 57% OM group). Analgesic use reduced significantly in the LM group (94% at baseline vs. 6% at endpoint) but not in systemic groups (IM group 97% vs. 86%, OM group 94% vs. 80%). Health-related quality of life was higher in the LM group than in the systemic groups. In mixed modelling, increased age was associated with a lower response to methylcobalamin.

CONCLUSIONS

This study indicates that local injection of methylcobalamin produces significant pain relief from SOHN and is superior to systemic administration.

The efficacy of pregabalin for the management of acute and chronic postoperative pain in thoracotomy: a meta-analysis with trial sequential analysis of randomized-controlled trials

PURPOSE

Pregabalin is commonly used as an analgesic for neuropathic pain. But pregabalin as an adjunct to a multimodal analgesic regimen - although standard clinical protocol in some settings - has remained controversial. This meta-analysis was conducted to identify the efficacy of pregabalin for management of postoperative pain in thoracotomy.

MATERIALS AND METHODS

Pubmed, Embase, Cochrane, Web of Science, Springer, and Clinical Trial Register database were searched for randomized controlled trials (RCTs) of pregabalin in preventing postoperative pain in thoracotomy. Review Manager 5.3 and STATA 12.0 were selected to conduct the meta-analysis. Trial sequential analysis was used to control random errors and calculate the required information size.

RESULTS

Nine RCTs with 684 patients were included in our meta-analysis. Outcomes favoring pregabalin included less pain on a 0-10 scale on 1 day [mean difference (MD): -0.87; 95% CI: -1.55 to -0.19; P=0.01], 3 days (MD: -1.55; 95% CI: -1.93 to -1.18; P<0.00001), 1 month (MD: -1.58; 95% CI: -2.75 to -0.42; P=0.008), 3 months (MD: -1.69; 95% CI: -2.71 to -0.66; P=0.001) postoperatively, and less incidence of neuropathic pain (OR: 0.20; 95% CI: 0.05-0.91; P=0.04), less mean morphine consumption (MD: -5.03; 95% CI: -8.06 to -1.99; P=0.001), but more dizziness (OR: 3.33; 95% CI: 1.36-8.17; P=0.009), more drowsiness (OR: 8.61; 95% CI: 2.23-33.20; P=0.002), and less constipation (OR: 0.23; 95% CI: 0.09-0.59; P=0.002). There was no statistical differences in pain score on 7 days (MD:-0.77; 95% CI: -2.38 to 0.84; P=0.35), nausea (OR: 0.73; 95% CI: 0.42-1.26; P=0.26), and vomiting (OR: 0.83; 95% CI: 0.36-1.90; P=0.65).

CONCLUSION

Pregabalin can prevent postoperative pain in thoracotomy and decrease incidence of neuropathic pain and morphine consumption. Pregabalin may be a valuable asset in management of acute and persistent postoperative pain in thoracotomy.