Myasthenia Crisis Induced by Pegylated-Interferon in Patient With Chronic Hepatitis C: A Case Report.

Myasthenia gravis is occasionally associated with thymoma that needs surgical resection and may progress to severe respiratory failure. We experienced a rare case of myasthenia crisis during antiviral therapy for chronic hepatitis C, in whom mediastinal thymoma was discovered and successfully managed with surgical thymectomy and meticulous medical care.A 47-year-old-male patient complained of sudden diplopia 1 week after stopping 11-week administration of pegylated-interferon and ribavirin for chronic hepatitis C. Ophthalmologic examinations revealed ptosis on the right eyelid and restricted right eye movement. Myasthenia gravis was confirmed by positive repetitive nerve stimulation test and positive serum antiacetylcholine receptor antibody test, and mediastinal thymoma was found on chest CT scan. The ocular myasthenia gravis progressed to respiratory failure even after discontinuing antiviral treatment but eventually recovered with thymectomy, anticholinesterase administration, steroid pulse therapy, and prolonged ventilator care. We describe the clinical features of this life-threatening complication of interferon treatment along with previous myasthenia crisis cases by interferon for chronic hepatitis C.In patients with chronic hepatitis C who is going to receive interferon-based antiviral treatment, physicians need to keep in mind the potential life-threatening manifestations of myasthenia gravis before and during antiviral treatment especially when patients complain of muscular weakness and easy fatigability.

Effects of inflammatory cytokine gene polymorphisms on warfarin maintenance doses in Korean patients with mechanical cardiac valves.

Cytokines that are involved in inflammation are related to blood coagulation, which could indirectly affect warfarin dose requirements. This study aimed to examine the effects of inflammatory cytokine gene polymorphisms on warfarin dose requirements for Korean patients with mechanical heart valves. In total, 191 patients with mechanical heart valves who were on warfarin anticoagulation therapy and maintained INR levels of 2-3 for three consecutive occasions were retrospectively followed up. In addition to vitamin K epoxide reductase complex subunit 1 (VKORC1) and cytochrome P450 (CYP) 2C9 polymorphisms, the interferon-γ, interleukin-1ß (IL1B), interleukin-6, interleukin-10, transforming growth factor-ß1 (TGFB1), tumor necrosis factor-α, and C-reactive protein genotypes were determined. The predictive contribution of age, VKORC1, and CYP2C9 to variability was 46.0 %. The addition of IL1B and TGFB1 polymorphisms increased the R (2) to 48.8 % for stable dose requirements, and significantly higher doses were found, especially when the TGFB1 CC genotype was combined with the IL1B TT genotype. Based on the results, it was concluded that inflammatory cytokine genes, such as TGFB1 and IL1B, can be predictive variables for stable warfarin doses in Korean patients.

Pharmacokinetic evaluation of formulated levodopa methyl ester nasal delivery systems.

The objective of this study was to investigate the pharmacokinetic characteristics of levodopa (L-dopa) from nasal powder formulations using highly water-soluble levodopa methyl ester hydrochloride (LDME). In vivo pharmacokinetic studies were carried out with formulated LDME nasal powders. After oral and intravenous administration of L-dopa and carbidopa and intranasal administration LDME to the rat, L-dopa concentrations were determined in plasma and the brain using high-performance liquid chromatography. The absolute bioavailabilities of nasal preparations with and without Carbopol were 82.4 and 66.7 %, respectively, which were much higher than that of oral delivery (16.2 %). The drug-targeting efficiencies [area under the curve (AUC) in brain/AUC in plasma] of L-dopa in the nasal formulations (0.98-1.08) were much higher than that of oral preparation (0.69). These results suggest that LDME nasal powder formulations would be useful delivery systems of L-dopa to the brain.

In vitro and in vivo evaluation of phenylbutenoid dimers as inhibitors of P-glycoprotein.

The expression of P-glycoprotein (P-gp), an ATP-dependent efflux transporter, is closely associated with the failure of chemotherapy and drug absorption. Two synthesized optically active phenylbutenoid dimers, 3S-(3,4-dimethoxyphenyl)-4R-{(E)-3,4-dimethoxystyryl}cyclohex-1-ene (1) and 3R-(3,4-dimethoxyphenyl)-4S-{(E)-3,4-dimethoxystyryl}cyclohex-1-ene (2), were tested for their P-gp inhibitory effects by measuring cellular accumulation and efflux of daunomycin in P-gp-overexpressed human breast cancer cells (MCF-7/ADR). Compound 2 significantly increased the accumulation of daunomycin (539%) and decreased the efflux of this compound (55.4%), and similar results were observed for 1. ATPase assays and Western blot analysis were performed to identify the mechanisms by which compounds 1 and 2 inhibit P-gp. In addition, changes in the pharmacokinetic profile of paclitaxel coadministered with 2 in rats were evaluated. Paclitaxel (25 mg/kg) when orally administered with 2 (5 mg/kg) improved its relative bioavailability by 185%. Compound 2 effectively improved cellular accumulation by reducing the efflux of daunomycin and significantly enhanced oral exposure to paclitaxel. Therefore, compound 2 may be useful for improving oral exposure and cellular availability of drugs that are also substrates of P-gp.

Comparison of budesonide and dexamethasone for local treatment of oral chronic graft-versus-host disease.

PURPOSE: The results of a prospective study of topical budesonide versus topical dexamethasone therapy for oral manifestations of chronic graft-versus-host disease (cGVHD) are presented. METHODS: In a prospective single-center investigation, a cohort of patients who developed oral symptoms of cGVHD after allogeneic stem cell transplantation were assigned to topical treatment with 0.03% budesonide rinse (group A, n = 26) or 0.01% dexamethasone rinse (group B, n = 24). Diagnosis of oral cGVHD symptoms, clinical staging, and treatment response scoring were performed at baseline and one month later according to current National Institutes of Health consensus criteria. RESULTS: At one-month follow-up, there was a significant decrease in the median oral cGVHD examination score in both groups (p < 0.001); the decrease in the median examination score was greater with budesonide versus dexamethasone therapy (2.5 points versus 1.0 point, p = 0.045). The rates of overall treatment response, including complete and partial responses, were 53.8% and 29.2% in groups A and B, respectively (p = 0.093). In addition, there was a significant decrease from baseline in the median self-rated oral pain severity score in group A (p < 0.001). CONCLUSION: Patients who received topical budesonide or dexamethasone rinse to treat oral manifestations of cGVHD had decreased cGVHD severity and pain scores after 30 days compared with baseline scores, though no statistical differences were seen between groups.