Comparison of the Efficacy of Duloxetine and Pregabalin in Pain Relief Associated with Diabetic Neuropathy

Efficacy and safety of duloxetine in painful diabetic peripheral neuropathy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Painful diabetic peripheral neuropathy (PDPN) is a key concern in clinical practice. In this systematic review and meta-analysis, we compared duloxetine and placebo treatments in terms of their efficacy and safety in patients with PDPN.

METHODS

Following the PRISMA guidelines, we searched the Cochrane Library, PubMed, and Embase databases for relevant English articles published before January 11, 2021. Treatment efficacy and safety were assessed in terms of pain improvement, patient-reported health-related performance, and patients' quality of life.

RESULTS

We reviewed a total of 7 randomized controlled trials. Regarding pain improvement, duloxetine was more efficacious than placebo (mean difference [MD] - 0.89; 95% confidence interval [CI] - 1.09 to - 0.69; P < .00001). Furthermore, duloxetine significantly improved the patients' quality of life, which was assessed using the Clinical Global Impression severity subscale (MD - 0.48; 95% CI - 0.61 to - 0.36; P < .00001), Patient Global Impression of Improvement scale (MD - 0.50; 95% CI - 0.64 to - 0.37; P < .00001), and European Quality of Life Instrument 5D version (MD 0.04; 95% CI 0.02 to 0.07; P = .0002). Severe adverse events were rare, whereas nausea, somnolence, dizziness, fatigue, constipation, and decreased appetite were common; approximately, 12.6% of all patients dropped out because of the common symptoms.

CONCLUSIONS

Duloxetine is more efficacious than placebo treatments in patients with PDPN. The rarity of severe adverse events indicates that duloxetine is safe. When a 60-mg dose is insufficient, 120 mg of duloxetine may improve PDPN symptoms. Our findings may help devise optimal treatment strategies for PDPN.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021225451.

CDC Clinical Practice Guideline for Prescribing Opioids for Pain - United States, 2022

This guideline provides recommendations for clinicians providing pain care, including those prescribing opioids, for outpatients aged ≥18 years. It updates the CDC Guideline for Prescribing Opioids for Chronic Pain - United States, 2016 (MMWR Recomm Rep 2016;65[No. RR-1]:1-49) and includes recommendations for managing acute (duration of <1 month), subacute (duration of 1-3 months), and chronic (duration of >3 months) pain. The recommendations do not apply to pain related to sickle cell disease or cancer or to patients receiving palliative or end-of-life care. The guideline addresses the following four areas: 1) determining whether or not to initiate opioids for pain, 2) selecting opioids and determining opioid dosages, 3) deciding duration of initial opioid prescription and conducting follow-up, and 4) assessing risk and addressing potential harms of opioid use. CDC developed the guideline using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. Recommendations are based on systematic reviews of the scientific evidence and reflect considerations of benefits and harms, patient and clinician values and preferences, and resource allocation. CDC obtained input from the Board of Scientific Counselors of the National Center for Injury Prevention and Control (a federally chartered advisory committee), the public, and peer reviewers. CDC recommends that persons with pain receive appropriate pain treatment, with careful consideration of the benefits and risks of all treatment options in the context of the patient's circumstances. Recommendations should not be applied as inflexible standards of care across patient populations. This clinical practice guideline is intended to improve communication between clinicians and patients about the benefits and risks of pain treatments, including opioid therapy; improve the effectiveness and safety of pain treatment; mitigate pain; improve function and quality of life for patients with pain; and reduce risks associated with opioid pain therapy, including opioid use disorder, overdose, and death.

A randomized control trial of duloxetine and gabapentin in painful diabetic neuropathy

BACKGROUND

To analyze the efficacy and safety of duloxetine and gabapentin in painful diabetic neuropathy (PDN).

METHODS

A randomized, open-label, active control, 12-week trial was conducted. A total of 86 participants were randomized in 1:1 ratio into gabapentin 300 mg and duloxetine 60 mg groups. The primary efficacy objective was comparison of mean change in Visual Analogue Scale (VAS) (0-100 points) scores between duloxetine and gabapentin. The symptom scores and adverse events were assessed as secondary outcomes.

RESULTS

Statistically significant (P value<.001) improvement was observed in VAS scores in both duloxetine group and gabapentin group at 12 weeks as compared to baseline. However, no significant difference in VAS scores between duloxetine and gabapentin. Similar improvement in diabetic neuropathy symptoms (DNS), diabetic neuropathy examination (DNE), and neuropathic disability score (NDS) was observed in either group over 12 weeks. There were no significant differences in DNS (P = 0.578), DNE (P = 0.410), and NDS (P = 0.071) scores between the two treatment groups. The overall safety evaluation of both duloxetine and gabapentin were similar. The most common adverse events reported were gastrointestinal.

CONCLUSION

The results indicated that both drugs were effective for the symptomatic relief from PDN and had similar efficacy. Follow-up of patients was only for 12 weeks and therefore the long-term efficacy and safety of the study drugs could not be assessed.

Lysophosphatidic Acid Receptor 1- and 3-Mediated Hyperalgesia and Hypoalgesia in Diabetic Neuropathic Pain Models in Mice

Lysophosphatidic acid (LPA) signaling is known to play key roles in the initiation and maintenance of various chronic pain models. Here we examined whether LPA signaling is also involved in diabetes-induced abnormal pain behaviors. The high-fat diet (HFD) showing elevation of blood glucose levels and body weight caused thermal, mechanical hyperalgesia, hypersensitivity to 2000 or 250 Hz electrical-stimulation and hyposensitivity to 5 Hz stimulation to the paw in wild-type (WT) mice. These HFD-induced abnormal pain behaviors and body weight increase, but not elevated glucose levels were abolished in LPA₁^−/− and LPA₃^−/− mice. Repeated daily intrathecal (i.t.) treatments with LPA_1/3 antagonist AM966 reversed these abnormal pain behaviors. Similar abnormal pain behaviors and their blockade by daily AM966 (i.t.) or twice daily Ki16425, another LPA_1/3 antagonist was also observed in db/db mice which show high glucose levels and body weight. Furthermore, streptozotocin-induced similar abnormal pain behaviors, but not elevated glucose levels or body weight loss were abolished in LPA₁^−/− and LPA₃^−/− mice. These results suggest that LPA₁ and LPA₃ play key roles in the development of both type I and type II diabetic neuropathic pain.