Risk and association of HLA with oxcarbazepine-induced cutaneous adverse reactions in Asians

OBJECTIVE

To investigate the risk and genetic association of oxcarbazepine-induced cutaneous adverse reactions (OXC-cADRs), including Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), in Asian populations (Chinese and Thai).

METHODS

We prospectively enrolled patients with OXC-cADRs in Taiwan and Thailand from 2006 to 2014, and analyzed the clinical course, latent period, drug dosage, organ involvement, complications, and mortality. We also investigated the carrier rate of HLA-B*15:02 and HLA-A*31:01 of patients with OXC-cADRs and compared to OXC-tolerant controls. The incidence of OXC-SJS/TEN was compared with carbamazepine (CBZ)-induced SJS/TEN according to the nationwide population dataset from the Taiwan National Health Insurance Research Database.

RESULTS

We enrolled 50 patients with OXC-cADRs, including 20 OXC-SJS/TEN and 6  drug reaction with eosinophilia and systemic symptoms, of Chinese patients from Taiwan and Thai patients from Thailand. OXC-cADRs presented with less clinical severity including limited skin detachment (all ≦5%) and no mortality. There was a significant association between HLA-B*15:02 and OXC-SJS (p = 1.87 × 10^-10; odds ratio 27.90; 95% confidence interval [CI] 7.84-99.23) in Chinese and this significant association was also observed in Thai patients. The positive and negative predictive values of HLA-B*15:02 for OXC-SJS/TEN were 0.73% and 99.97%, respectively. HLA-A*31:01 was not associated with OXC-cADRs. The incidence and mortality of OXC-SJS/TEN was lower than CBZ-STS/TEN in new users (p = 0.003; relative risk 0.212; 95% CI 0.077-0.584).

CONCLUSIONS

Our findings suggest that HLA-B*15:02 is significantly associated with OXC-SJS in Asian populations (Chinese and Thai). However, the severity and incidence of OXC-SJS/TEN are less than that of CBZ-SJS/TEN. The need for preemptive HLA-B*15:02 screening should be evaluated further.

Evidence-based approach to the medical management of trigeminal neuralgia

Classical trigeminal neuralgia (TN) is a rare neuropathic pain with distinct diagnostic criteria. The aim of this review is to provide recommendations for medical management based on current evidence and provide some pointers on the conduct of future trials. A review of the literature identified four systematic reviews, of which one was a meta-analysis and 18 randomized controlled trials (RCT) on medical management of trigeminal neuralgia. The evidence suggests that carbamazepine is still the first line drug for medical management, but this should be changed to oxcarbazepine if there is poor efficacy and an unacceptable side effect profile. Combination of carbamazepine with lamotrigine or baclofen is the second line treatment when monotherapy fails, but the evidence is weak. An early neurosurgical opinion should be sought when a patient has a neurovascular contact of the trigeminal nerve, poor efficacy and tolerability of drug treatment and no remission periods. Many of the new antiepileptic drugs need to be evaluated in RCTs with innovative designs and robust outcome measures.

Pilot study to evaluate the efficacy and tolerability of levetiracetam (Keppra) in treatment of patients with trigeminal neuralgia

BACKGROUND AND PURPOSE

The objective of this study was to determine whether levetiracetam (LEV) is an effective drug for treatment of trigeminal neuralgia (TN).

METHODS

Ten patients with TN were enrolled in a 10-week, prospective, open-label pilot study. The primary outcome measure was the visual analogue scale on daily pain diary and side effects. Serum levels of LEV were measured to assess correlation between drug levels and pain control.

RESULTS

There was a significant tendency towards improvement in pain severity compared with baseline in four patients with higher doses of 4,000 mg/day. The four treatment responders had less pain compared with baseline (50-90% improvement) and three subjects continued the drug after study completion. All patients rated themselves on the global evaluation scale as much improved (n = 2), minimally improved (n = 3), no change (n = 1), minimally worse (n = 2), much worse (n = 1) and very much worse (n = 1). LEV was very well tolerated and there was no difference in side effects between the low and high doses of LEV evaluations.

CONCLUSION

Given its established safety profile, a randomized, placebo-controlled, double-blind trial of LEV using enhancement enrollment design is needed to confirm these open-labelled findings using a wide variety of outcome measures.

Age estimation in three distinct east Asian population groups using southern Han Chinese dental reference dataset

Background

Dental age estimation can assist in the identification of victims following natural disasters and it can also help to solve birth date disputes in individuals involved in criminal activities. A reference dataset (RDS) has been developed from the dental development of 2306 subjects of southern Han Chinese origin and subsequently validated. This study aimed to test the applicability of the southern Han Chinese dental maturation RDS on three distinct East Asian population groups.

Methods

A total of 953 dental panoramic radiographs of subjects aged 2 to 24 years were obtained from Philippines, Thailand and Japan. The staging of dental development was conducted according to Anglo-Canadian classification system. The dental age (DA) was calculated using six methods; one un-weighted average and five weighted average (n-tds, sd-tds, se-tds, 1/sd-tds, 1/se-tds) methods based on the scores of the southern Han Chinese RDS. Statistical significance was set at p < 0.05 and the variation between chronological age (CA) and DA was evaluated using paired t-test and Bland & Altman scatter plots.

Results

From six dental age calculations, all methods of DA accurately estimated the age of Japanese and few methods in Filipino subjects (n-tds, 1/sd-tds, 1/se-tds). There was consistent overestimation of age for all the methods for Thai females (p < 0.05).

Conclusions

The southern Han Chinese dental reference dataset was shown to be most accurate for Japanese, followed by Thai males and it was particularly ineffective for Filipinos and Thai females.

Efficacy and safety of two artificial saliva-based polymers containing 0.1% pilocarpine for treatment of xerostomia: A randomized clinical pilot trial

Background

Topical agents are the mainstay in the treatment of xerostomia, a common complaint most frequently associated with salivary dysfunction. This study aimed to compared the efficacy and safety for xerostomia treatment of 2 artificial saliva preparations containing 0.1% pilocarpine, and, either sodium carboxymethylcellulose (SCMC), or, sodium polyacrylate (SPA).

Material and Methods

Thirty-one xerostomia patients were randomly allocated into either a SCMC-treated group (15 patients), or, a SPA-treated group (16 patients). The formulations were taken 0.5 ml, 4 times daily for 6 weeks and double-blinded assessed before and after treatments using Xerostomia Inventory (XI) and Clinical Oral Dryness Score (CODs). Unstimulated and stimulated whole salivary flow rates were measured.

Results

After treatment, the SCMC-treated group had significantly lower CODs and higher unstimulated and stimulated whole salivary flow rates (p<0.001, p=0.035, and p=0.013, respectively), while the SPA-treated group showed significantly lower CODs only (p=0.004). In contrast, SCMC-treated and SPA-treated groups at the 6th week after treatments showed non-significant differences in all assessments (p>0.05, all). Some adverse events (AEs) were reported, e.g., burning tongue, dizziness and watery eyes, but no severe AEs.

Conclusions

This randomized controlled pilot trial demonstrated superior efficacy of SCMC-formula over a SPA-formula after 6 weeks of xerostomia treatment. These formulations with topical pilocarpine proved safe in clinical use with minimal reported AE.

Key words:Xerostomia, artificial saliva, sodium carboxymethylcellulose, sodium polyacrylate, pilocarpine.

Efficacy and safety of lacosamide in patients with trigeminal neuralgia: an 8-week pilot dose-escalation study

BACKGROUND

Trigeminal neuralgia (TN) is a severe neuropathic pain condition in the orofacial region, with carbamazepine recommended as the first-line treatment. Nonetheless, its application is constrained by unfavorable drug responses and side effects. The objective of this research was to assess the effectiveness and safety of lacosamide, a third-generation anticonvulsant, in individuals with TN, and to juxtapose the findings with observational records from recently diagnosed TN patients who underwent carbamazepine monotherapy within the corresponding timeframe.

METHODS

An 8-week flexible dose titration of lacosamide was performed on newly diagnosed 12 TN patients who were divided into two groups: 200 mg/day (n = 5), and 400 mg/day (n = 7). Outcome measures included average pain score, Brief Pain Inventory-facial scores, and side effects. Patients were followed-up at 2, 4 and 8 weeks after baseline.

RESULTS

The percentage change of pain score at 4-week visit was compared between both lacosamide groups and patients receiving carbamazepine (n = 6) for four weeks during concurrent period. Both lacosamide groups experienced a decrease in pain score at 2-week follow-up, and differences in average pain score reduction were not observed between the two groups across all visits (p > 0.05). The mean Brief Pain Inventory-facial score in the lacosamide 200 mg/day group was higher than that in the 400 mg/day group at the 2-week follow-up (p = 0.03). Interestingly, the 4-week follow-up revealed that there were no significant variances in pain intensity between the lacosamide and the contemporaneous carbamazepine cohorts (p > 0.05). Frequently noted adverse events were mild somnolence (n = 9), slight vertigo (n = 5), and emotional lability (n = 2) without instances of severe adverse drug responses.

CONCLUSIONS

Lacosamide demonstrates potential as a therapeutic option for patients suffering from trigeminal neuralgia.

CLINICAL TRIAL REGISTRATION

TCTR20210811002.