Rebound after discontinuation of teriflunomide in patients with multiple sclerosis: 2 case reports.

Teriflunomide is an oral first-line disease modifying treatment (DMT) for patients with relapsing-remitting multiple sclerosis (RRMS). It can take up to two years to achieve systemic clearance of teriflunomide to an acceptable level, but this washout period may be accelerated by administration of cholestyramine. Relapse of multiple sclerosis (MS) during washout of teriflunomide or other first-line DMT is not as common. We report two patients with RRMS who experienced a relapse after the accelerated elimination period (AEP) of teriflunomide and confirmation of negative plasmatic levels (<0.02 µg/ml). In cases of risk of MS activity, we should not wait for teriflunomide negative plasmatic levels confirmation before starting the next DMT to reduce the risk of relapse.

Tolerability and efficacy of colestipol hydrochloride for accelerated elimination of teriflunomide.

BACKGROUND: Teriflunomide is an oral disease modifying therapy approved for the treatment of relapsing forms of multiple sclerosis. Teriflunomide' s pharmacokinetics (PK) contribute to its slow elimination, on average taking 6-8 months, though it can take up to 2 years in some instances. This slow elimination can become problematic in certain clinical situations - such as during pregnancy, when teriflunomide has potential teratogenic effects. In such scenarios, an accelerated elimination procedure (AEP) is recommended. Currently, AEPs with oral cholestyramine or activated charcoal are available but are restricted by adverse effects, limited administration routes, and dosing frequencies. METHODS: A single-center, PK interaction study was performed in a total of 14 healthy volunteers, to investigate colestipol hydrochloride (HCl) as an alternative to cholestyramine for the elimination of teriflunomide. Participants received teriflunomide for 14 days, followed by an AEP with colestipol HCl for 15 days. RESULTS AND CONCLUSIONS: The administration of colestipol HCl for 15 days was sufficient to reduce plasma teriflunomide concentrations by greater than 96%. Although colestipol HCl did not completely eliminate teriflunomide with the same effectiveness as cholestyramine, it may offer an alternative method for accelerated elimination of teriflunomide with potentially improved tolerability and more favorable dosing and administration options.

Efficacy of cholestyramine ointment in reduction of postoperative pain and pain during defecation after open hemorrhoidectomy: results of a prospective, single-center, randomized, double-blind, placebo-controlled trial.

BACKGROUND: The aim of the present study was to evaluate the efficacy of cholestyramine ointment (15 %) in reducing postoperative pain at rest and during defecation after open hemorrhoidectomy. METHODS: A total of 91 patients with third and fourth degree hemorrhoids undergoing open hemorrhoidectomy were included in this prospective, double-blind, randomized controlled trial. The patients were randomly assigned to either cholestyramine ointment or placebo immediately after surgery, 12 h after surgery, and then every 8 h for 14 days. The primary outcomes were intensity of pain at rest and during defecation, measured with a visual analog scale, and the analgesic requirement, measured by amount of tramadol consumption. RESULTS: The cholestyramine group had less postoperative pain than the placebo group at the 24th hour (1.84 ± 2.54 vs. 4.07 ± 3.35; P = 0.001) and 48th hour (0.18 ± 0.88 vs. 3.57 ± 3.45; P < 0.001) and less pain during defecation starting at the 48th hour (2.28 ± 2.96 vs. 4.77 ± 4.09; P = 0.001). Similarly, the average tramadol consumption at hours 24 and 48 was significantly lower for the cholestyramine group (5.32 ± 21.45 vs. 43.18 ± 61.56 mg at 24 h, and 4.48 ± 16.65 vs. 57.63 ± 65.47 mg at 48 h; P < 0.001). The only adverse event was pruritus, which had a lower frequency in the cholestyramine group but the difference was not significant until postoperative week 4 (P < 0.001). CONCLUSIONS: Compared with placebo, cholestyramine ointment (15%) reduced postoperative pain at rest and on defecation, and consequently lowered the analgesic requirement after open hemorrhoidectomy.

The Bile Acid Sequestrant Acceptability scale validation study.

AIMS: The primary objective of this study was to validate a novel Bile Acid Sequestrant Acceptability (BASA) Scale intended to assess the acceptability and/or tolerability of bile acid sequestrant (BAS) beverage preparations. A secondary objective was to assess the utility of weightings based on subjective clinical importance for the BASA scale individual components and its composite score. METHODS: This was a randomised, single-blind, single site, controlled study of oral administration of 4 g of orange-flavoured generic cholestyramine powder, 12 g of orange-flavoured generic cholestyramine powder and an orange-flavoured sweetened control drink powder, each mixed with water. RESULTS: The study sample included 42 subjects; 26 men and 16 women. Participants were non-Hispanic white (76.2%) or black/African American (23.8%), with a mean age of 51.4 years and body mass index of 30.1 kg/m(2). The components of the BASA scale were taste, texture, appearance and mixability; the possible total BASA scores ranged being 4-20; the higher the BASA scale score, the better the acceptability/tolerability. Composite BASA scale scores were significantly lower for the 4 g (mean BASA score = 10.3) and 12 g (mean BASA score = 9.4) cholestyramine compared with the control drink powder (mean BASA score = 16.7) (p < 0.001). BASA scale scores did not significantly differ between the 4 and 12 g of cholestyramine. (p = 0.215). Weighting of the components did not materially alter the results. Findings for the individual components of the BASA scale were similar to the composite values. CONCLUSION: The BASA scale effectively distinguished between an orange-flavoured BAS powder and a commercial orange-flavour control powder.

Development of sustained release fast-disintegrating tablets using various polymer-coated ion-exchange resin complexes.

Complex formation between drugs and ion-exchange resins was investigated and the effects of coating by various aqueous polymeric dispersions on the complexes were evaluated for developing new sustained-release fast-disintegrating tablets (FDTs). Complexes of ion-exchange resin and dextromethorphan, a model drug, were prepared using different particle sizes of the resins. Aqueous colloidal dispersions of ethylcellulose (EC) and poly(vinyl acetate) (Kollicoat SR30D) were used for fluid-bed coating. Based on drug loading, release profiles, and scanning electron microscopy (SEM) images, the coated particles were granulated with suitable tablet excipients and then compressed into the tablets. Drug release profiles and SEM pictures were compared before and after the manufacturing processes. As the particle size of resins increased, the drug loading and release rate decreased due to the reduced effective diffusion coefficient and surface area. Higher coating level decreased the release rate further. In contrast to EC, Kollicoat SR30D coated particles could be compressed into tablets without any rupture or cracks on the coating since the mechanical properties of the polymer was more resistant to the manufacturing processes. This resulted in no significant changes in release rates. SEM showed the mechanical strength of the polymers affected the morphological change after compression. When the drug release profiles were applied into Boyd model and Higuchi equation, the linear relationship was observed, indicating that the diffusion within the resin matrix is the rate-controlling step.

Drug release properties of polymer coated ion-exchange resin complexes: experimental and theoretical evaluation.

Although ion-exchange resins have been used widely as drug delivery systems, their exact release kinetics has not been reported yet. Usually only the rate-limiting step has been taken into account and the rest of the steps have been ignored as instantaneous processes. To investigate the exact release kinetics of polymer-coated drug/ion-exchange resin complexes for sustained drug delivery, the results of new mathematical modeling were compared with experimental results. Drug/resin complexes with a model drug, dextromethorphan, were prepared and used as cores for fluid-bed coating. An aqueous colloidal dispersion of poly(vinyl acetate) was applied for the coating. A comprehensive mathematical model was developed using a mechanistic approach by considering diffusion, swelling, and ion-exchange processes solved by numerical techniques. The rate-limiting factor of the uncoated resin particles was diffusion through the core matrix. Similarly, in the coated particles the rate-limiting factor was diffusion through the coating membrane. The mathematical model has captured the phenomena observed during experimental evaluations and the release dynamics from uncoated and coated (at different coat levels) particles were predicted accurately (maximum RMSE 2.4%). The mathematical model is a useful tool to theoretically evaluate the drug release properties from coated ion-exchange complexes thus can be used for design purposes.

Atovaquone plus cholestyramine in patients coinfected with Babesia microti and Borrelia burgdorferi refractory to other treatment.

Ten percent of US patients with Lyme disease are coinfected with Babesia microti. A double-blind, placebo-controlled, crossover trial enrolled 25 patients with confirmed Borrelia burgdorferi/B microti coinfection, abnormal visual contrast sensitivity (VCS), and persistent symptoms despite prior treatment with atovaquone and azithromycin. Patients were randomly assigned to atovaquone suspension or placebo plus cholestyramine for 3 weeks, were crossed over for 3 weeks, and then received open-label atovaquone and cholestyramine for 6 weeks. Symptoms and VCS scores were recorded at baseline and after weeks 3, 6, 9, and 12. Improvements in symptoms and VCS deficits were observed only after at least 9 weeks of treatment. At week 12, 5 patients were asymptomatic, and 16 had a notable reduction in the number of symptoms. The entire cohort demonstrated significant increases in VCS scores. Adverse effects were rare. Patients coinfected with B burgdorferi and B microti derive measurable clinical benefit from prolonged treatment with atovaquone and cholestyramine. Longer-term combination therapy may be indicated.

Efficacy of colestimide coadministered with atorvastatin in japanese patients with heterozygous familial hypercholesterolemia (FH).

BACKGROUND: Colestimide, a 2-methylimidazole-epichlorohydrin polymer, is a new bile-acid-sequestering resin, that is 4-fold as powerful at lowering low-density lipoprotein cholesterol (LDL-C) as the conventional resin (cholestyramine). Moreover, colestimide has excellent patient compliance because it is available in tablet form. METHODS AND RESULTS: The clinical efficacy of colestimide coadministered with atorvastatin on lipid and apolipoprotein concentrations was examined in 15 patients (M/F=10/5, mean+/-SE age=54+/-9 years) with heterozygous familial hypercholesterolemia (FH). After a period of wash-out of any lipid-lowering drugs, atorvastatin (20-40 mg) was administered to patients for at least 8 weeks, and then 3 g of colestimide was administered for a further 8 weeks. Total and LDL-C significantly (<0.0001) decreased by 35% from 361 to 233 mg/dl and 41% from 274 to 161 mg/dl, respectively. Addition of colestimide caused a further significant 12% and 20% reduction, respectively, from the initial values to 205 and 129 mg/dl, respectively. Colestimide was also effective in reducing serum LDL-C concentrations in heterozygous FH patients with hypertriglyceridemia (triglycerides>or=150 mg/dl). CONCLUSIONS: When monotherapy with atorvastatin is insufficient to treat severely hypercholesterolemic patients, such as those with heterozygous FH, colestimide acts to reinforce the action of statins.

[Managing methotrexate toxicity: a case report]. / Manejo de la intoxicación por metotrexato: a propósito de un caso.

High-dose methotrexate is included in chemotherapy regimens used to treat a number of malignant neoplasms. Methotrexate plasma concentration is considered the best toxicity predictor. Monitoring methotrexate plasma concentrations is standard practice in the identification of at-risk patients, the titration of folinic acid doses, and the establishment of corrective measures. Methotrexate is a kidney-cleared weak acid, and renal function impairment may retard methotrexate clearance. A case of severe methotrexate-induced toxicity secondary to renal failure is reported in a patient with non-Hodgkin s lymphoma receiving methotrexate at a dose of 1 g/m2. Corrective measures included folinic acid rescue therapy, cholestyramine resin administration, hydration and urine alkalinization, urine pH monitoring, and extracorporeal clearance techniques.

Colestimide can be used as a phosphate binder to treat uraemia in end-stage renal disease patients.

Colestimide is a potent therapeutic compound used widely for treatment of hypercholesterolaemia, and it was discovered coincidentally that it can be used to lower the serum phosphate concentration in cases of secondary hyperparathyroidism with refractory hyperphosphataemia. Colestimide is useful for treating hyperphosphataemia in end-stage renal disease (ESRD) patients undergoing haemodialysis. Twenty-eight patients who were being treated for hyperphosphataemia with 3.5+/-1.1 g/day calcium carbonate were enrolled in the study. Colestimide was added to their prescription for 4 weeks at a mean dosage of 2.3 g/day. The serum phosphate concentration decreased significantly from 6.1+/-1.1 mg/dl before treatment to 5.3+/-1.1 mg/dl at 4 weeks (P<0.0001). The calcium-phosphate product also decreased significantly from 59.6+/-11.3 mg/dl(2) before treatment to 50.5+/-12.0 mg/dl(2) (P<0.0001). The serum total cholesterol significantly (P<0.001) decreased at 1 week and remained constant until the end of treatment. Colestimide is a cationic polymer with chloride as the counterion. Its chemical structure resembles that of sevelamer hydrochloride, which is already being used clinically as a phosphate binder. This suggests that colestimide uses the same mechanism as sevelamer hydrochloride to treat hyperphosphataemia. The present results demonstrate that colestimide can function as a Ca-free, aluminium-free, non-absorbable, phosphate binder in ESRD patients. In addition, colestimide can reduce the serum phosphate concentration in combination with calcium carbonate.

Inhibition of ileal bile acid absorption by colestimide.

BACKGROUND: Colestimide is a new type of anion-exchange resin in Japan, but its effect on bile acid absorption in the ileum has not been studied. METHODS: Absorption of ursodeoxycholate, tauroursodeoxycholate, cholate, taurocholate and taurolithocholate-sulfate in rat ileum was compared in the presence and absence of colestimide. Bile acid adsorption by colestimide in vitro was also studied. RESULTS: All bile acids were efficiently absorbed by the ileum, and the cumulative absorption during 60 min was 25-78%. The absorption of ursodeoxycholate, tauroursodeoxycholate and taurocholate was inhibited by colestimide, whereas that of cholate and taurolithocholate-sulfate was not inhibited by colestimide. Adsorption of bile acids by colestimide in vitro was higher with taurine conjugates than with the unconjugated forms. CONCLUSIONS: Colestimide was shown to be useful to inhibit the physiologically important ileal absorption of bile acid amides in vivo.

Tauroursodeoxycholate and cholestyramine enhance biliary carcinogenesis in hamsters.

The aim of this study was to examine whether tauroursodeoxycholate (TUDC) and cholestyramine resin (CR) enhance biliary carcinogenesis in the hamster model. A cholecystoduodenostomy with dissection of the extrahepatic bile duct on the distal end of the common duct was performed on Syrian hamsters. The hamsters were then divided randomly into 3 groups: control group, TUDC-treated group, and CR-treated group. All animals received N-nitrosobis(2-oxopropyl)amine (BOP) to initiate pancreaticobiliary cancer. The experiment was terminated at week 16 and the number of neoplastic lesions was counted microscopically. In the TUDC group, the intrahepatic biliary carcinogenesis was more accelerated than that observed in the control group, but no promoting effect was seen in the pancreas, gallbladder, or extrahepatic bile duct. In the CR group, both the intrahepatic biliary and the gallbladder carcinogenesis were inhibited compared with that observed in the control group and the TUDC group. TUDC enhanced the intrahepatic bile duct carcinogenesis, whereas CR inhibited both the intrahepatic bile duct and the gallbladder carcinoma. Bile acids were suggested to promote biliary carcinoma in the hamster model.

Combination drug therapy for dyslipidemia.

Effective treatment of dyslipidemia improves prognosis. Statin therapy has been documented to decrease the cardiovascular event rate in the setting of elevated low-density lipoprotein (LDL) cholesterol levels and coronary heart disease, but most patients are not treated to the target (LDL