Gabapentinoids for Pruritus in Older Adults: A Narrative Review

Prescribing Patterns and Off-Label Use of Gabapentinoid Agents at Dhulikhel Hospital, Nepal: A Cross-Sectional Study

Purpose

Gabapentinoids are mainly prescribed for neuropathic pain and certain seizure disorders, but their off-label use has increased significantly. This rise raises concerns about the insufficient evidence supporting some applications, as well as potential risks of misuse, dependence, and adverse effects. The study aims to examine the prescribing patterns and off-label use of gabapentinoids at Dhulikhel Hospital (DH), Nepal, focusing on understanding the extent of off-label practices and patient knowledge regarding their medications.

Patients and Methods

A cross-sectional survey of 385 adult patients prescribed gabapentinoids was conducted at the outpatient pharmacy of DH. Data were collected via patient interviews and prescriptions. Off-label use was assessed according to the licensed indications of the US Food and Drug Administration (FDA) and the UK British National Formulary (BNF). Statistical analysis was performed using Statistical Package for the Social Sciences version 26.

Results

Among patients prescribed gabapentinoids, 73.0% received gabapentin while 27.0% were prescribed pregabalin. Most patients were middle-aged females with comorbid conditions, primarily orthopedic outpatients. Off-label use was prevalent, with 96.1% of prescriptions being off-label by FDA indications and 28.1% by BNF indications. Pregabalin was prescribed at a sub-therapeutic dose (75 mg/day) for neuropathic pain. Patient knowledge about gabapentinoids was found to be poor, particularly regarding side effects and drug interactions.

Conclusion

This study highlights the extensive off-label and sub-therapeutic use of gabapentinoids at Dhulikhel Hospital and reveals significant gaps in patient knowledge. This emphasizes the need for stricter prescribing guidelines, improved healthcare provider education, and better patient information to optimize the use and minimize risks. The frequent prescription of low-dose pregabalin for neuropathic pain raises the possibility that it may be used for night-time sedation rather than for pain management, indicating the need for further investigation.

Effectiveness of Postburn Pruritus Treatment and Improvement of Insomnia-A Randomized Trial

Postburn pruritus is difficult to assess and treat. Antihistamines used in its treatment provide little relief. Identification of the itch neuronal pathway has inspired new alternatives, including gabapentin, for its management. The study compared the effectiveness of cetirizine, gabapentin, and a combination of gabapentin and cetirizine in treating postburn pruritus. Burn patients were randomly assigned to treatment with Cetirizine (n = 23), Gabapentin (n = 23), or Cetirizine plus Gabapentin (n = 23). A baseline assessment of the intensity or the severity of pruritus was evaluated, after which treatment commenced with standard doses of the 3 study regimens. Quality of sleep was assessed at baseline (day 0) and repeated on day 3, day 7, and day 14. Approximately 97% of participants presented with moderate or severe itch; 69% with acute itch; and the majority (94.2%) experienced pruritus between the first and fourth weeks. Gabapentin reduced itch by 92.9% in 14 days compared to cetirizine's 61.8%. The combined effect of cetirizine and gabapentin was comparable using gabapentin alone. When the itch became protracted over 6 weeks, the effectiveness of cetirizine in controlling itch worsened. It reduced itch intensity by only 37.7%, whilst gabapentin did so at 89.4%. Itch intensity correlated positively with insomnia, and controlling itch intensity improved sleep. Gabapentin was more effective for the treatment of postburn pruritus than cetirizine. Controlling itch intensity improved sleep. In acute and moderate itch, low-dose gabapentin could be added if cetirizine is the drug intended for its treatment.

Itching Frequency and Neuroanatomic Correlates in Frontotemporal Lobar Degeneration

Importance

Itching is common in geriatric populations and is frequently linked to dermatological or systemic conditions. Itching engages specific brain regions that are implicated in the pathogenesis of frontotemporal lobar degeneration spectrum disorders (FTLD-SD). Thus, itching of undetermined origin (IUO) may indicate the presence of a neurodegenerative process.

Objective

To compare the frequency of itching in FTLD-SD and Alzheimer disease (AD) and to determine the neuroanatomical underpinnings of IUO.

Design, Setting, and Participants

This case-control study evaluated data and brain magnetic resonance images (MRIs) for participants with FTLD-SD or AD. Participants of a research study on FTLD-SD at the University of California, San Francisco, Memory and Aging Center were evaluated from May 1, 2002, to December 31, 2021. The exposure group underwent structural brain MRI within 6 months of initial diagnosis. Research visit summaries were reviewed to validate qualitative details and accurately identify itching with undetermined origin (IUO).

Exposures

Symptoms suggestive of FTLD-SD or AD.

Main Outcomes and Measures

Frequency of itching in FTLD-SD and AD and neuroanatomic correlates.

Results

A total of 2091 research visit summaries were reviewed for 1112 patients exhibiting symptoms indicative of FTLD-SD or AD. From 795 records where itching or a related phrase was endorsed, 137 had IUO. A total of 454 participants were included in the study: 137 in the itching group (mean [SD] age, 62.7 [9.9] years; 74 [54%] females and 63 males [46%]) and 317 in the nonitching group (mean [SD] age, 60.7 [10.8] years; 154 [49%] females and 163 males [51%]). Groups were similar in age, sex, and disease severity. More frequent itching was found in FTLD-SD (95/248 patients [38%], of which 44 [46%] had behavioral variant frontotemporal dementia [bvFTD]) compared with the AD group (14/77 patients [18%]; P = .001). The odds of itching were 2.4 (95% CI, 1.48-3.97) times higher for FTLD-SD compared with all other cases of dementia. Compared with healthy controls, the group with IUO exhibited greater gray matter atrophy bilaterally in the amygdala, insula, precentral gyrus, and cingulum, as well as in the right frontal superior gyrus and thalamus. Among patients with bvFTD and itching vs bvFTD without itching, itching was associated with right-lateralized gray matter atrophy affecting the insula, thalamus, superior frontal gyrus, and cingulum.

Conclusions and Relevance

Among individuals with IUO, FTLD-SD was disproportionately represented compared with AD. In FTLD-SD, dysfunction in the right anterior insula and its connected regions, including the right precentral gyrus, cingulum, and bilateral amygdala, contribute to dysregulation of the itching-scratching networks, resulting in uncontrollable itching or skin picking. Awareness among physicians about the relationship between neurodegeneration and itching may help in the management of itch in older individuals. Further studies are needed to determine the best treatments for these symptoms in patients with neurodegenerative disorders.

Treatment of Brachioradial Pruritus: A Tertiary Center Retrospective Analysis

This retrospective study investigates the efficacy of 2 treatment regimens, pregabalin alone versus pregabalin combined with ketamine, amitriptyline, and lidocaine cream, in reducing itch in patients with brachioradial pruritus at a tertiary care center. Electronic medical records of 64 brachioradial pruritus patients seen at the University of Miami Itch Center were analyzed. A significant reduction in itch scores was seen with both treatments, with no significant difference between the groups. A small number of patients experienced adverse effects, including drowsiness and weight gain with pregabalin and skin irritation with ketamine, amitriptyline, and lidocaine cream. Ultimately, our findings underscore the potential of utilizing combined therapy for difficult-to-treat brachioradial pruritus cases and implementing individualized approaches for managing neuropathic pruritus. Further controlled clinical trials are needed to establish optimal treatment protocols.

Prescription Practices Regarding the use of Systemic Drugs in the Management of Patients with Chronic Pruritus amongst Indian Dermatologists - A Questionnaire Based Survey

Background

Chronic pruritus poses a significant challenge to treating physicians due to multitude of underlying causes and varying treatment strategies. Several topical, systemic, and physical modalities have been tried with variable success. Prescription practices in chronic pruritus are influenced by differential knowledge and experience of physicians, patient-related factors, and resource availability.

Aim

The purpose of this survey was to observe the current pattern of practice in Indian dermatologists in the management of chronic pruritus and to identify practice gaps particularly regarding the use of various systemic agents as antipruritics.

Materials and Methods

A previously validated questionnaire was sent to consultant dermatologists across India between January 2020 and July 2020. The questionnaire was comprised of six questions (multiple-choice questions as well as open-ended questions) regarding the use of antidepressants, cyclic gamma-aminobutyric acid (GABA) analogues, opioid antagonists, antihistamines, and alternate therapies in the management of chronic pruritus.

Results

A total of 700 dermatologists completed the questionnaire (response rate 70%). Overall, antihistamines were the most common drug prescribed in chronic pruritus (more than 95% respondents). Other systemic agents such as opioid antagonists, gabapentinoids, and antidepressants were prescribed by 22.42%, 71.85%, and 75.29% respondents, respectively, in chronic pruritus as either monotherapy or in combination with antihistamines in specific types of itches. Among antidepressants, tricyclic antidepressants (TCAs) (69.29%) were prescribed most often, followed by selective serotonin reuptake inhibitors (SSRIs) (32.29%) and serotonin and norepinephrine reuptake inhibitors (SNRIs) (9.14%). Other treatment options such as omalizumab, thalidomide, ondansetron, ursodeoxycholic acid (UDCA), and rifampicin were used by 10% respondents to alleviate pruritus in special situations.

Conclusion

This survey revealed the redundant practice of prescribing antihistamines in chronic pruritus irrespective of etiology among Indian dermatologists. It also revealed a differential approach regarding use of systemic agents such as gabapentinoids, opioid antagonists, and antidepressants, in academic and non-academic institutions. The survey emphasized a barrier in writing prescription of systemic agents such as opioid antagonist and SNRIs due to lack of knowledge and experience, fear of side effects, and inadequate available evidence.

Assessment and Management of Sleep Disturbances in Atopic Dermatitis: A Review

Atopic dermatitis (AD) is a chronic burdensome inflammatory skin disease with well-established cutaneous and systemic comorbidities and disease burden. AD particularly has profound impacts on sleep in individuals of all ages. Sleep disturbances (SDs) affect 6.2% of school-age children and 33-87.1% of adults with AD. This narrative review addresses the burden of SD in AD patients, as well as biological mechanisms of SD in AD, including biological clocks influencing sleep, inflammation, and behavior. Approaches for early detection, diagnosis, objective quantification, patient education, and management are reviewed. It is imperative to break the itch-scratch cycle to reduce SDs and improve quality of life in individuals with AD.

Gabapentin and oral antidepressants for chronic pruritus: a prospective cohort study evaluating efficacy and side effects in daily dermatological practice

BACKGROUND

Chronic pruritus is frequently seen in daily dermatological practice and is associated with marked impact on quality of life. Research on the use of gabapentin and oral antidepressants in daily dermatological practice is scarce.

OBJECTIVE

To evaluate the efficacy and safety of gabapentin and oral antidepressants in patients with chronic pruritus in daily clinical practice.

METHODS

A prospective observational single-center cohort study was conducted including adult patients with chronic pruritus and an indication for systemic treatment between June 2016 and May 2019.

RESULTS

Systemic treatment with gabapentin and/or antidepressants was initiated in 31 patients with severe chronic pruritus (median average pruritus NRS score 7.0), in which most cases no underlying origin was identified (83.9%). In patients treated with gabapentin 900-1800 mg/day (N = 25), median average pruritus NRS decreased to 5.5 (IQR 3.0) after 4 weeks and remained stable up to 24 weeks of treatment. Efficacy of antidepressants was variable, with the highest response after initiation of amitriptyline, nortriptyline, and mirtazapine. Side effects were frequently observed in both gabapentin and antidepressant treatments; however, were mostly mild and temporary.

LIMITATIONS

This was a single-site observational study, with limited sample size.

CONCLUSION

Treatment with gabapentin and antidepressants should be considered in patients with chronic pruritus unresponsive to conventional treatment.

A rare case report: chronic generalized idiopathic pruritus

Background

Generalized chronic pruritus (CP) can be associated with seborrheic dermatitis and psoriasis but often can present without any noticeable diagnosis or obvious skin lesion. When not related to a clear diagnosis, CP can be characterized as idiopathic pruritus. CP is both a diagnostically and therapeutically challenging presentation due to the variety of systemic, dermatological, neurological, and psychogenic diseases that must be ruled out before diagnosing idiopathic pruritus. This presentation is often overlooked but can lead to a greatly diminished quality of life for patients who present with idiopathic generalized pruritus. The course of treatment will vary between providers and specialties, however, most dermatologists will attempt control with antihistamines, topical steroids, or oral steroids. The use of gabapentinoids for the treatment of CP is understudied. Gabapentin was initially developed as an antiepileptic that has since been approved to treat neuropathic pain and has a common off-label use in dermatology and can be used to effectively treat CP.

Case Description

Here we present a case of a 56-year-old Caucasian male who presented to the outpatient dermatology clinic with new-onset, diffuse, and intense pruritic symptoms that gradually progressed over a period of seven weeks. This case study details a patient with Idiopathic generalized pruritus previously uncontrolled that was well-controlled with the use of gabapentin after trials of other common treatments failed.

Conclusions

The understudied off-label use of gabapentin in the case of generalized chronic idiopathic pruritus should be explored and later implemented as a mainstay for patients suffering from uncontrolled CP as it was shown to completely eliminate pruritic symptoms and improve the quality of life for this patient.

Kappa opioid agonists in the treatment of itch: just scratching the surface?

Chronic pruritus is a debilitating condition affecting 23-44 million Americans. Recently, kappa opioid agonists (KOAs) have emerged as a novel class of potent antipruritic agents. In 2021, the Food and Drug Administration approved difelikefalin (Korsuva) for the treatment of moderate-to-severe pruritus associated with chronic kidney disease in adults undergoing hemodialysis. Difelikefalin is a potent, peripherally restricted KOA that is intravenously available. Although promising, difelikefalin is currently available as an intravenous composition only, limiting the scope of use. Oral formulations of difelikefalin did not meet the primary endpoint criteria in recent phase 2 clinical trials; however, additional clinical studies are ongoing. The future for KOAs in the treatment of pruritus is encouraging. Orally active pathway-biased KOAs, such as triazole 1.1, may serve as viable alternatives with broader applications. Extended-release compositions, such as the TP-2021 ProNeura subdermal implant, may circumvent the pharmacokinetic issues associated with peptide-based KOAs. Lastly, dual-acting kappa opioid receptor agonist/mu opioid receptor antagonists are orally bioavailable and may be useful in the treatment of various forms of chronic itch. In this review, we summarize the results of KOAs in clinical and preclinical trials and discuss future directions of drug development.

[Neuropathic pruritus-Evidence-based treatment recommendations]

Neuropathic pruritus is a previously neglected symptom of a wide range of neurological diseases. Peripheral nerve or root compression syndromes, space-occupying lesions of the central nervous system, chronic inflammatory neurological diseases and polyneuropathy can cause neuropathic pruritus. Even when the identification of the underlying neurological disease is successful, a direct causal treatment is not always possible, hence an effective symptomatic treatment remains the only therapeutic option. The purpose of this review article is to present the current literature on various therapeutic agents and options in the treatment of neuropathic pruritus.

Comparison of Pregabalin and Ketotifen in Treatment of Uremic Pruritus in Hemodialysis Patients

This study aims to compare the efficiency of Pregabalin and Ketotifen in treatment of uremic pruritus in hemodialysis (HD) patients. Thirty HD patients were randomly divided into two groups: A (Pregabalin 50 mg 3 times a day) and B (Ketotifen 1mg twice a day). Efficacy of treatment and quality of life were weekly evaluated by visual analogue scale (VAS) and Itchy Quality of life, respectively. There was no significant difference between the two groups regarding demographic features, laboratory data, quality of life, and VAS before treatment. In the second week of treatment, the pruritus intensity was significantly lower in the Pregabalin group than the Ketotifen group (p=0.026). The mean of life quality was significantly lower in Ketotifen than Pregabalin group in weeks 1, 2, and 4 (P=0.001, P=0.001, and P=0.036, respectively). There was no significant difference between the two groups regarding the side effects of drugs. This study showed that a higher dose of Pregabalin could be a more effective treatment than Ketotifen without additive side effects in improving the quality of life in dialysis patients. This article is protected by copyright. All rights reserved.

Epidemiology of adult chronic cough: disease burden, regional issues, and recent findings

Chronic cough is a common medical condition that has a significant impact on patients' quality of life. Although it was previously considered a symptom of other disorders, it is now regarded as a pathologic state that is characterized by a deviation from the intrinsic protective functions of the cough reflex, especially in adults. There are several factors that may underlie the cough reflex hypersensitivity and its persistence, such as age, sex, comorbidities, viral infection, exposure to irritants or environmental pollutants, and their interactions may determine the epidemiology of chronic cough in different countries. With a deeper understanding of disease pathophysiology and advanced research methodology, there are more attempts to investigate cough epidemiology using a large cohort of healthcare population data. This is a narrative overview of recent findings on the disease burden, risk factors, Asia-Pacific issues, and longitudinal outcomes in adults with chronic cough. This paper also discusses the approaches utilizing routinely collected data in cough research.