Hydroxychloroquine dosing and toxicity: A real-world experience in Saudi Arabia of 63 patients

Inhibition of transient receptor potential vanilloid 3 channels by antimalarial hydroxychloroquine alleviates TRPV3-dependent dermatitis

Transient receptor potential vanilloid 3 channel (TRPV3) is closely associated with skin inflammation, but there is a lack of effective and specific inhibitors for clinical use. In this study, we identified antimalarial hydroxychloroquine (HCQ) as a selective TRPV3 inhibitor following the prediction by network pharmacology data analysis. In whole-cell patch-clamp recordings, HCQ inhibited the current of the TRPV3 channel, with an IC50 of 51.69 ± 4.78 μM. At the single-channel level, HCQ reduced the open probability of TRPV3 and decreased single-channel conductance. Molecular docking and site-directed mutagenesis confirmed that residues in the pore domain were critical for the activity of HCQ. In vivo, HCQ effectively reduced carvacrol-induced epidermal thickening, erythema, and desquamation. Additionally, the serum immunoglobulin E and inflammatory factors such as tumor necrosis factor-α and interleukin-6 were markedly decreased in the dorsal skin tissues in the HCQ treatment group, as compared to the model group. Our results suggested the antimalarial HCQ may represent a potential alleviator for treating skin inflammation by inhibiting TRPV3 channels.

A Methodological Review of Drug-Related Toxicological Studies in Saudi Arabia

This study aimed to conduct a methodological review of drug-related toxicological studies in Saudi Arabia. A systematic review and a methodological analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Medline and Embase were searched for all types of studies reporting toxicological studies in the English language published until January 10, 2022. The search was conducted using both keywords and Medical Subject Headings (MeSH) terms. The methodological analysis of included studies was assessed using the Newcastle-Ottawa Scale. A total of 3,750 studies were extracted and screened. Of these, 30 observational studies (seven cohort studies and 23 cross-sectional studies) met the inclusion criteria. The methodological scores ranged from five to seven out of 10 possible points. Twelve studies had high quality, and 18 studies had moderate quality. Eight studies focused on adverse drug reactions, eight explored poisoning, four explored drug-related hospitalizations, nine explored drug-induced toxicity, and one explored drug overdose. This research project revealed that most of the drug-related toxicological studies conducted in Saudi Arabia were observational studies of moderate quality. Future studies should focus on the quality of the design and reporting.

Knowledge of Saudi Patients with Autoimmune Diseases about Hydroxychloroquine Toxicity: The Role of Physician-Patient Communication

This cross-sectional internet-based questionnaire aimed to assess the knowledge and experience of autoimmune disease patients in Saudi Arabia of the ocular effects of hydroxychloroquine (HCQ). Among the 245 respondents, discontinuation of the drug was linked to its ocular toxicity in approximately 7.3%. Most patients had taken HCQ for a period longer than five years, exceeding a dose of 5 mg/Kg. A lack of education and physician communication about medication toxicity was reported by approximately 40.8% of the participants. Despite the knowledge about HCQ retinopathy, the drug is prescribed to autoimmune disease patients at an inappropriate dosage. Knowledge obtained from physicians' communication may improve the health outcomes of chronically ill patients. Rheumatologists and ophthalmologists should work together to recognize patients at risk of hydroxychloroquine toxicity and ensure they receive proper education and adhere to periodic follow-up.