Fentanyl for neuropathic pain in adults

Efficacy and safety of venlafaxine versus nortriptyline for the preventive treatment of migraine: A double-blind randomized clinical trial

OBJECTIVE

Migraine, as a primary headache disorder, stands as one of the primary causes of disability worldwide. Consequently, prophylactic treatments are highly recommended for individuals experiencing recurrent migraine episodes. Our study aimed to compare the efficacy and safety profiles of venlafaxine and nortriptyline in the prophylactic management of migraine.

METHODS

In this single-center, randomized, double-blind clinical trial, 210 migraine patients were allocated into two groups in a 1:1 ratio. One group received venlafaxine (37.5 mg, orally twice daily), while the other group administered nortriptyline (25 mg, orally once daily). A neurologist documented (1) headache intensity using the Visual Analog Scale (VAS) and 6-point Behavioral Rating Scale (BRS-6), (2) headache frequency (per month), and (3) headache duration (in hours) of participants on days 0, 45, and 90 of the intervention.

RESULTS

Following the 90-day intervention, a significant decrease was observed in VAS, BRS-6, frequency, and duration of headaches within both groups (all with p-values <0.001). No difference in VAS, BRS-6, or headache durations was observed between the two groups after 45 and 90 days of treatment (all p-values > 0.05). Although the headache frequency exhibited no difference between the groups after 45 days (p-value = 0.097), a significantly lower frequency in the venlafaxine group was observed at day 90 of the intervention (p-value = 0.011). The reductions in attack parameters in the 0-45- and 0-90-day intervals did not meet statistical significance between the two groups (p-values > 0.05). 77.0 % of the participants in the venlafaxine group and 79.2 % in the nortriptyline group experienced a minimum of 50 % improvement in all attack parameters. Venlafaxine demonstrated a statistically significant lower incidence of adverse reactions in comparison to nortriptyline (p-value = 0.005). A total of 33 adverse drug reactions were documented in the venlafaxine group and 53 in the nortriptyline group, with insomnia observed in the former and xerostomia in the latter as the most prevalent side effects.

CONCLUSIONS

Venlafaxine and nortriptyline demonstrate clinically significant and comparable therapeutic efficacy for migraine patients in reducing the intensity, frequency, and duration of headache attacks. Venlafaxine may be preferred to nortriptyline in the context of migraine preventive treatment under comparable conditions due to its lower incidence of adverse effects.

ZY5301 Tablet vs Placebo for Treatment of Chronic Pelvic Pain After Pelvic Inflammatory Disease: A Phase 2 Randomized Clinical Trial

Importance

Chronic pelvic pain (CPP) is the main sequela of pelvic inflammatory disease (PID), with no established treatment. ZY5301 tablets, an effective part preparation extracted from Ajuga decumbens Thunb. (jingucao), are being tested as a treatment for CPP caused by PID.

Objective

To evaluate whether ZY5301 tablets are effective and safe for CPP treatment in women with PID.

Design, Setting, and Participants

This placebo-controlled double-blind, dose-parallel, phase 2 randomized clinical trial was conducted in 9 hospitals in China. Female participants with CPP after PID were enrolled between October 16, 2020, and August 31, 2021. The data analysis was performed between December 2021 and March 2022.

Interventions

Participants were randomized 1:1:1 to receive ZY5301 300 mg/d, ZY5301 600 mg/d, or placebo orally 3 times a day for 12 weeks.

Main Outcomes and Measures

Visual analog scale (VAS) scores were the main measure used to evaluate the efficacy of ZY5301 in reducing CPP. The evaluation end points for VAS score included changes in mean weekly VAS score from baseline, area under the VAS score-time curve, pain remission (VAS score of 0 and 1) rate, and median time to pain remission. Safety was evaluated by the occurrence of treatment-emergent and treatment-related adverse events.

Results

In total, 180 women were randomly assigned, and 177 were included in the efficacy analysis; thus, the full analysis set included 60 participants in the ZY5301 mg/d group (mean [SD] age, 37.4 [8.1] years), 58 in the ZY5301 600 mg/d group (mean [SD] age, 37.1 [7.9] years), and 59 in the placebo group (mean [SD] age, 38.9 [7.3] years). Participant characteristics at baseline were similar among the groups. After 12 weeks of treatment, the mean (SD) change in VAS score from the baseline was -2.1 (1.7) points, -3.5 (1.5) points, and -3.8 (1.7) points in the placebo, ZY5301 300 mg/d, and ZY5301 600 mg/d groups, respectively (P < .001). The pain remission rates at week 12 were 43.3% and 53.5% in the ZY5301 300 mg/d and ZY5301 600 mg/d groups, respectively, a significant difference compared with the placebo group (11.9%; P < .001). All the other end points showed similar improvements. The ZY5301 600 mg/d group had better efficacy than the ZY5301 300 mg/d group, but the difference was not significant. The safety analysis revealed no significant differences among groups.

Conclusions and Relevance

These findings show that ZY5301 tablet is efficacious for the relief of CPP with acceptable tolerability.

Trial Registration

ClinicalTrials.gov Identifier: NCT05460546.

Neuropathic pain: Evidence based recommendations

Neuropathic pain continues to be a significant problem that lacks effective solutions for every single patient. In 2015, international guidelines (NeuPSIG) were published, while the French recommendations were updated in 2020. The purpose of this minireview is to provide an update on the process of developing evidence-based recommendations and explore potential changes to the current recommendations. Primary treatments for neuropathic pain include selective serotonin-norepinephrine reuptake inhibitors (SNRIs) such as duloxetine and venlafaxine, gabapentin, tricyclic antidepressants, as well as topical lidocaine and transcutaneous electrical nerve stimulation, which are specifically suggested for focal peripheral neuropathic pain. Pregabalin is a first line treatment according to international guidelines but second-line in the more recent French guidelines, due to lower efficacy seen in more recent studies and misuse risk. Additionally, tramadol, combination therapies, and psychotherapy as adjuncts are proposed second line; high-concentration capsaicin patches, and botulinum toxin A are proposed specifically for focal peripheral neuropathic pain. In cases where primary and secondary treatments prove insufficient, third-line options come into play. These include high-frequency repetitive transcranial magnetic stimulation (rTMS) targeting the motor cortex, spinal cord stimulation, and the use of strong opioids when no alternative is available. To ensure optimal management of neuropathic pain in real-life situations, it is imperative to disseminate these recommendations widely and secure the acceptance of practitioners. By doing so, we can bridge the gap between theory and practice, and enhance the overall care and treatment of individuals suffering from neuropathic pain.

Therapeutic Approach for Trigeminal Neuralgia: A Systematic Review

This umbrella review aimed to determine the various drugs used to treat trigeminal neuralgia (TN) and to evaluate their efficacies as well as side effects by surveying previously published reviews. An online search was conducted using PubMed, CRD, EBSCO, Web of Science, Scopus, and the Cochrane Library with no limits on publication date or patients' gender, age, and ethnicity. Reviews and meta-analyses of randomized controlled trials pertaining to drug therapy for TN, and other relevant review articles added from their reference lists, were evaluated. Rapid reviews, reviews published in languages other than English, and reviews of laboratory studies, case reports, and series were excluded. A total of 588 articles were initially collected; 127 full-text articles were evaluated after removing the duplicates and screening the titles and abstracts, and 11 articles were finally included in this study. Except for carbamazepine, most of the drugs had been inadequately studied. Carbamazepine and oxcarbazepine continue to be the first choice for medication for classical TN. Lamotrigine and baclofen can be regarded as second-line drugs to treat patients not responding to first-line medication or for patients having intolerable side effects from carbamazepine. Drug combinations using carbamazepine, baclofen, gabapentin, ropivacaine, tizanidine, and pimozide can yield satisfactory results and improve the tolerance to the treatment. Intravenous lidocaine can be used to treat acute exaggerations and botulinum toxin-A can be used in refractory cases. Proparacaine, dextromethorphan, and tocainide were reported to be inappropriate for treating TN. Anticonvulsants are successful in managing trigeminal neuralgia; nevertheless, there have been few studies with high levels of proof, making it challenging to compare or even combine their results in a statistically useful way. New research on other drugs, combination therapies, and newer formulations, such as vixotrigine, is awaited. There is conclusive evidence for the efficacy of pharmacological drugs in the treatment of TN.

Non-response to first-line hormonal treatment for symptomatic endometriosis: overcoming tunnel vision. A narrative review

One-fourth to one-third of women with endometriosis receiving first-line hormonal treatment lacks an adequate response in terms of resolution of painful symptoms. This phenomenon has been ascribed to "progesterone resistance", an entity that was theorized to explain the gap between the ubiquity of retrograde menstruation and the 10% prevalence of endometriosis among women of reproductive age.Nevertheless, the hypothesis of progesterone resistance is not free of controversies. As our understanding of endometriosis is increasing, authors are starting to set aside the traditionally accepted tunnel vision of endometriosis as a strictly pelvic disease, opening to a more comprehensive perspective of the condition. The question is: are patients not responding to first-line treatment because they have an altered signaling pathway for such treatment, or have we been overlooking a series of other pain contributors which may not be resolved by hormonal therapy?Finding an answer to this question is evermore impelling, for two reasons mainly. Firstly, because not recognizing the presence of further pain contributors adds a delay in treatment to the already existing delay in diagnosis of endometriosis. This may lead to chronicity of the untreated pain contributors as well as causing adverse consequences on quality of life and psychological health. Secondly, misinterpreting the consequences of untreated pain contributors as a non-response to standard first-line treatment may imply the adoption of second-line medical therapies or of surgery, which may entail non-negligible side effects and may not be free of physical, psychological and socioeconomic repercussions.The current narrative review aims at providing an overview of all the possible pain contributors in endometriosis, ranging from those strictly organic to those with a greater neuro-psychological component. Including these aspects in a broader psychobiological approach may provide useful suggestions for treating those patients who report persistent pain symptoms despite receiving first-line hormonal medical treatment.

Trends in Prescriptions for Non-opioid Pain Medications Among U.S. Adults With Moderate or Severe Pain, 2014-2018

As opioid prescribing has declined, it is unclear how the landscape of prescription pain treatment across the U.S. has changed. We used nationally-representative data from the Medical Expenditure Health Survey, 2014 to 2018 to examine trends in prescriptions for opioid and non-opioid pain medications, including acetaminophen, non-steroidal anti-inflammatory drugs, gabapentinoids, and antidepressants among U.S. adults with self-reported pain. Overall, from 2014 to 2018, the percentage of participants receiving a prescription for opioids declined, (38.8% vs 32.8%), remained stable for non-steroidal anti-inflammatory drugs (26.8% vs 27.7%), and increased for acetaminophen (1.6% vs 2.3%), antidepressants (9.6% vs 12.0%) and gabapentinoids (13.2% vs 19.0%). In this period, the adjusted odds of receiving an opioid prescription decreased (aOR = .93, 95% CI = .90-.96), while the adjusted odds of receiving antidepressant, gabapentinoid and acetaminophen prescriptions increased (antidepressants: aOR = 1.08, 95% CI = 1.03-1.13 gabapentinoids: aOR = 1.11, 95% CI = 1.06-1.17; acetaminophen: aOR = 1.10, 95% CI: 1.02-1.20). Secondary analyses stratifiying within the 2014 to 2016 and 2016 to 2018 periods revealed particular increases in prescriptions for gabapentinoids (aOR = 1.13, 95% CI = 1.05-1.21) and antidepressants (aOR = 1.23, 95% CI = 1.12-1.35) since 2016. PERSPECTIVE: These data demonstrate that physicians are increasingly turning to CDC-recommended non-opioid medications for pain management, particularly antidepressants and gabapentinoids. However, evidence for these medications' efficacy in treating numerous common pain conditions, including low back pain, remains limited.

Pharmacovigilance in hospice/palliative care: Net effect of amitriptyline or nortriptyline on neuropathic pain: UTS/IMPACCT Rapid programme international consecutive cohort

BACKGROUND

Real-world effectiveness of interventions in palliative care need to be systematically quantified to inform patient/clinical decisions. Neuropathic pain is prevalent and difficult to palliate. Tricyclic antidepressants have an established role for some neuropathic pain aetiologies, but this is less clear in palliative care.

AIM

To describe the real-world use and outcomes from amitriptyline or nortriptyline for neuropathic pain in palliative care.

DESIGN

An international, prospective, consecutive cohort post-marketing/phase IV/pharmacovigilance/quality improvement study of palliative care patients with neuropathic pain where the treating clinician had already made the decision to use a tricyclic antidepressant. Data were entered at set times: baseline, and days 7 and 14. Likert scales graded benefits and harms.

SETTING/PARTICIPANTS

Twenty-one sites (inpatient, outpatient, community) participated in six countries between June 2016 and March 2019. Patients had clinician-diagnosed neuropathic pain.

RESULTS

One hundred and fifty patients were prescribed amitriptyline (110) or nortriptyline (40) of whom: 85% had cancer; mean age 73.2 years (SD 12.3); mean 0-4 scores for neuropathic pain at baseline were 1.8 (SD 1.0). By day 14, doses of amitriptyline were 57 mg (SD 21) and nortriptyline (48 mg (SD 21). Fifty-two (34.7%) patients had pain improvement by day 14 (amitriptyline (45/110 (43.3%); nortriptyline (7/40 (18.9%)). Thirty-nine (27.7%) had new harms; (amitriptyline 29/104 (27.9%); nortriptyline 10/37 (27.0%); dizziness (n = 23), dry mouth (n = 20), constipation (n = 14), urinary retention (n = 10)). Benefits without harms occurred (amitriptyline (26/104 (25.0%); nortriptyline (4/37 (10.8%)).

CONCLUSIONS

Benefits favoured amitriptyline while harms were similar for both medications.

Management of Neuropathic Pain in the Geriatric Population

Neuropathic pain is common in the geriatric population. Diagnosis requires a thorough history and physical examination to differentiate it from other types of pain. Once diagnosed, further workup is required to elucidate the cause, including potential reversible causes of neuropathy. When treating neuropathic pain in the elderly, it is important to consider patients' comorbidities and other medications to avoid drug-drug interactions and iatrogenic effects given the physiologic changes of drug metabolism in the elderly. Nonsystemic therapies and topical medications should be considered. Systemic medications should be started at low dose and titrated up slowly with frequent monitoring for adverse effects.

Patient Assisted Intervention for Neuropathy: Comparison of Treatment in Real Life Situations (PAIN-CONTRoLS): Bayesian Adaptive Comparative Effectiveness Randomized Trial

Importance

Cryptogenic sensory polyneuropathy (CSPN) is a common generalized slowly progressive neuropathy, second in prevalence only to diabetic neuropathy. Most patients with CSPN have significant pain. Many medications have been tried for pain reduction in CSPN, including antiepileptics, antidepressants, and sodium channel blockers. There are no comparative studies that identify the most effective medication for pain reduction in CSPN.

Objective

To determine which medication (pregabalin, duloxetine, nortriptyline, or mexiletine) is most effective for reducing neuropathic pain and best tolerated in patients with CSPN.

Design, Setting, and Participants

From December 1, 2014, through October 20, 2017, a bayesian adaptive, open-label randomized clinical comparative effectiveness study of pain in 402 participants with CSPN was conducted at 40 neurology care clinics. The trial included response adaptive randomization. Participants were patients with CSPN who were 30 years or older, with a pain score of 4 or greater on a numerical rating scale (range, 0-10, with higher scores indicating a higher level of pain). Participant allocation to 1 of 4 drug groups used the utility function and treatment's sample size for response adaptation randomization. At each interim analysis, a decision was made to continue enrolling (up to 400 participants) or stop the whole trial for success (80% power). Patient engagement was maintained throughout the trial, which helped guide the study and identify ways to communicate and disseminate information. Analysis was performed from December 11, 2015, to January 19, 2018.

Interventions

Participants were randomized to receive nortriptyline (n = 134), duloxetine (n = 126), pregabalin (n = 73), or mexiletine (n = 69).

Main Outcomes and Measures

The primary outcome was a utility function that was a composite of the efficacy (participant reported pain reduction of ≥50% from baseline to week 12) and quit (participants who discontinued medication) rates.

Results

Among the 402 participants (213 men [53.0%]; mean [SD] age, 60.1 [13.4] years; 343 White [85.3%]), the utility function of nortriptyline was 0.81 (95% bayesian credible interval [CrI], 0.69-0.93; 34 of 134 [25.4%] efficacious; and 51 of 134 [38.1%] quit), of duloxetine was 0.80 (95% CrI, 0.68-0.92; 29 of 126 [23.0%] efficacious; and 47 of 126 [37.3%] quit), pregabalin was 0.69 (95% CrI, 0.55-0.84; 11 of 73 [15.1%] efficacious; and 31 of 73 [42.5%] quit), and mexiletine was 0.58 (95% CrI, 0.42-0.75; 14 of 69 [20.3%] efficacious; and 40 of 69 [58.0%] quit). The probability each medication yielded the highest utility was 0.52 for nortriptyline, 0.43 for duloxetine, 0.05 for pregabalin, and 0.00 for mexiletine.

Conclusions and Relevance

This study found that, although there was no clearly superior medication, nortriptyline and duloxetine outperformed pregabalin and mexiletine when pain reduction and undesirable adverse effects are combined to a single end point.

Trial Registration

ClinicalTrials.gov Identifier: NCT02260388.

Analgesic opioid use disorders in patients with chronic non-cancer pain: A holistic approach for tailored management

Chronic pain is a major public health issue that frequently leads to analgesic opioid prescriptions. These prescriptions could cause addiction issues in high-risk patients with associated comorbidities, especially those of a psychiatric, addictive, and social nature. Pain management in dependent patients is complex and is yet to be established. By combining the views of professionals from various specialties, we conducted an integrative review on this scope. This methodology synthesizes knowledge and results of significant practical studies to provide a narrative overview of the literature. The main results consisted in first proposing definitions that could allow shared vocabulary among health professionals regardless of their specialties. Next, a discussion was conducted around the main strategies for managing prescription opioid dependence, as well as pain in the context of opioid dependence and associated comorbidities. As a conclusion, we proposed to define the contours of holistic management by outlining the main guidelines for creating a multidisciplinary care framework for multi-comorbid patients with chronic pathologies.

Pain Management in Patients with Serious Illness

Managing pain in patients with serious illness can be complex. However, pain is often a prominent symptom in patients with malignant and nonmalignant serious illness and providers have to be adept at balancing effective pain management and safety. Clinicians should start with a standard pain assessment that lays important groundwork for developing a tailored multimodal approach to pain management. It is important to identify physical causes of pain and also existential causes. Opioids are not always appropriate but are still an important tool for managing pain. Basic opioid management and safe practices are essential when managing this population.

Overlaps in pharmacology for the treatment of chronic pain and mental health disorders

There is significant overlap in the pharmacological management of pain and psychological disorders. Appropriate treatment of patients' comorbid psychological disorders, including sleep disturbances often leads to an improvement in reported pain intensity. The three first line agents for neuropathic pain include tricyclic antidepressants and serotonin norepinephrine reuptake inhibitors which are medications originally developed as antidepressants. The other first line medication for chronic neuropathic pain are anticonvulsant medications initially brought to the market-place for the treatment of epilepsy and are also now being used for the treatment of anxiety disorders and substance withdrawal symptoms. The efficacy of opioids for chronic pain is contentious, but it is agreed that the patients at highest risk for opioid misuse and addiction are patients with underlying psychological disorders who use opioids for their euphoric effects. Similarly, benzodiazepines may present a problem in patients with chronic pain, as up to one third of patients with pain are concomitantly prescribed benzodiazepines, and when combined with other sedating analgesic medications they put patients at increased risk for adverse events and polysubstance misuse. Finally, there is growing evidence for the efficacy of cannabis for treating neuropathic pain, but the consumption of cannabis has been associated with increased risk of psychosis in adolescents, and may be associated with an increased risk for developing bipolar disorder and anxiety disorders. The use of cannabis is associated with an increased risk of substance misuse in both adolescents and adults. In this narrative review, we examine the evidence for the use of several medications used for the treatment of both pain and psychological disorders, and their proposed mechanisms of action, in addition to special concerns for patients with comorbid pain and psychological disorders.

Lysergic acid diethylamide and psilocybin for the management of patients with persistent pain: a potential role?

Recently, there has been interest in lysergic acid diethylamide (LSD) and psilocybin for depression, anxiety and fear of death in terminal illness. The aim of this review is to discuss the potential use of LSD and psilocybin for patients with persistent pain. LSD and psilocybin are 5-hydroxytryptamine receptor agonists and may interact with nociceptive and antinociceptive processing. Tentative evidence from a systematic review suggests that LSD (7 studies, 323 participants) and psilocybin (3 studies, 92 participants) may be beneficial for depression and anxiety associated with distress in life-threatening diseases. LSD and psilocybin are generally safe if administered by a healthcare professional, although further investigations are needed to assess their utility for patients with persistent pain, especially associated with terminal illness.

Diagnosis and Treatment of Ocular Pain: the Ophthalmologist's Perspective

PURPOSE OF REVIEW

The aim of this review is to help ophthalmologists and other clinicians understand and treat ocular neuropathic pain.

RECENT FINDINGS

Advances in the field of neurophysiology of ocular sensations explain why some cases of dry eye may represent a pain syndrome rather than a problem related to tear status. Principles related to management of pain syndromes such as persistent post-operative pain and complex regional pain syndrome are relevant to the care of these patients.

SUMMARY

Specific strategies for the ophthalmologist, including multimodal therapy comprised of local and systemic approaches, can be helpful in the care of patients with problematic ocular pain. Rather than dismiss these syndromes and these patients, ophthalmologists can serve these patients and the profession well by incorporating an understanding of ocular neuropathic pain into their practice and by collaboration in the care of patients with problematic ocular pain.

Medication Treatment Efficacy and Chronic Orofacial Pain

Chronic pain in the orofacial region has always been a vexing problem for dentists to diagnose and treat effectively. For trigeminal neuropathic pain, there are 3 medications (gabapentinoids, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors) to use plus topical anesthetics that have therapeutic efficacy. For chronic daily headaches (often migraine in origin), 3 prophylactic medications have reasonable therapeutic efficacy (β-blockers, tricyclic antidepressants, and antiepileptic drugs). The 3 Food and Drug Administration-approved drugs for fibromyalgia (pregabalin, duloxetine, and milnacipran) are not robust, with poor efficacy. For osteroarthritis, nonsteroidal anti-inflammatory drugs have therapeutic efficacy and when gastritis contraindicates them, corticosteriod injections are helpful.