Colesevelam HCl (Welchol™), a new, potent, well tolerated, non systemic, lipid lowering agent

Low-dose combination therapy with colesevelam hydrochloride and lovastatin effectively decreases low-density lipoprotein cholesterol in patients with primary hypercholesterolemia

BACKGROUND

Colesevelam hydrochloride is a novel, lipid-lowering agent that binds bile acids with high affinity. A multicenter, randomized, double-blind, placebo-controlled, parallel-design study was conducted to assess the efficacy and tolerability of combination low-dose colesevelam and lovastatin treatment in patients with primary hypercholesterolemia.

HYPOTHESIS

Combination therapy with low doses of colesevelam and lovastatin decreases low density (LDL) cholesterol with minimal adverse events.

METHODS

Following a 4- to 6-week dietary lead in, 135 patients were randomized into five groups for a 4-week treatment period: placebo, colesevelam 2.3 g at dinner, lovastatin 10 mg at dinner, the combination of colesevelam and lovastatin given at dinner (dosed together), and combination treatment with colesevelam given at dinner and lovastatin administered at bedtime (dosed apart).

RESULTS

Combination colesevelam and lovastatin treatment decreased LDL cholesterol by 34% (60 mg/dl, p < 0.0001) and 32% (53 mg/dl, p < 0.0001) when colesevelam and lovastatin were dosed together or dosed apart, respectively. Both combination therapies were superior to either agent alone (p < 0.05). Decreases in LDL cholesterol exceeded the combined decreases observed for colesevelam alone (13 mg/dl, 7%) and lovastatin alone (39 mg/dl, 22%). Both combination treatments reduced total cholesterol by 21% (p < 0.0001) and apolipoprotein B by 24% (p < 0.0001). Neither combination treatment significantly altered high-density lipoprotein cholesterol or triglycerides. Adverse side effects were not significantly different among randomized groups.

CONCLUSIONS

Combination colesevelam and lovastatin was efficacious and well tolerated, resulting in additive decreases in LDL cholesterol levels whether or not both agents were administered simultaneously.

Colesevelam: Potential Uses for the Newest Bile Resin

Colesevelam is the newest bile resin with a unique chemical structure. It binds to bile acids with higher affinity than traditional bile acid sequestrants and has fewer gastrointestinal side effects and drug interactions. Colesevelam is safe and efficacious alone or in combination with HMG-CoA reductase inhibitors (statins) in reducing low-density lipoprotein cholesterol (LDL-C) levels. Despite this, the role of colesevelam in the treatment of hyperlipidemia remains limited, particularly in the face of new lipid lowering agents. As guidelines for cholesterol control become more stringent, the need to maximize therapeutic benefit through combination therapy will become increasingly more important. Colesevelam has a dose-sparing effect on statin therapy, potentially decreasing the risk of unwanted side effects or drug-drug interactions associated with statin use. This makes colesevelam a viable option for addition to a statin regimen when goal LDL-C levels cannot be achieved with a statin alone. Additionally, anecdotal reports indicate that colesevelam may have potential benefits in certain patient populations that cannot tolerate other lipid lowering therapies, including organ transplant recipients, cholestatic liver disesase, and end-stage renal disease. By recognizing the potential utility of colesevelam, clinicians can better manage those patients who are not able to tolerate first-line therapies.

Effects of colesevelam HC1 on sterol and bile acid excretion in patients with type IIa hypercholesterolemia

Colesevelam HC1 is a potent bile acid-binding polymer. This study's aim was to determine effects of colesevelam HCl on sterol and bile acid excretion in patients with type IIa hypercholesterolemia. Twenty-four patients (low-density lipoprotein cholesterol, 130 to 220 mg/dL) enrolled in an open-label, parallel-design study, entered an American Heart Association/National Cholesterol Education Program diet for 6 weeks and were randomized to colesevelam HCl, 2.3 or 3.8 g/day for 4 weeks. In an apparent dose-related manner, respective mean serum concentrations HCl of low-density lipoprotein cholesterol decreased by 10% (P < 0.01) and 13% (P = 0.05), mean total cholesterol levels decreased by 4.9% (P = 0.05) and 6.1% (P = 0.09), and total fecal bile acid excretion showed median changes of +324% (P < 0.05) and +316% (P < 0.05). Colesevelam HCl did not affect fecal neutral sterol or fecal fatty acid excretion; however, 24-hr urinary mevalonic acid levels significantly increased in both treatment groups (P < 0.05). The cholesterol-lowering action of colesevelam HCl appears to be mediated through increased bile acid excretion.

Efficacy and safety of combination simvastatin and colesevelam in patients with primary hypercholesterolemia

PURPOSE

To examine the efficacy and safety of colesevelam hydrochloride, a novel, nonsystemic, lipid-lowering agent, when coadministered with starting doses of simvastatin in a multicenter, randomized, double-blind, placebo-controlled trial.

PATIENTS AND METHODS

Subjects with hypercholesterolemia (plasma low density lipoprotein [LDL] cholesterol level > 160 mg/dL and triglyceride level < or = 300 mg/dL) were randomly assigned to receive daily doses of placebo (n = 33), colesevelam 3.8 g (recommended dose, n = 37), simvastatin 10 mg (n = 35), colesevelam 3.8 g with simvastatin 10 mg (n = 34), colesevelam 2.3 g (low dose, n = 36), simvastatin 20 mg (n = 39), or colesevelam 2.3 g with simvastatin 20 mg (n = 37), for 6 weeks.

RESULTS

Mean LDL cholesterol levels decreased relative to baseline in the placebo group (P < 0.05) and in all active treatment groups (P < 0.0001). For groups treated with combination therapy, the mean reduction in LDL cholesterol level was 42% (-80 mg/dL; P < 0.0001 compared with baseline), which exceeded the reductions for simvastatin 10 mg (-26%, -48 mg/dL) or 20 mg (-34%, -61 mg/dL) alone, or for colesevelam 2.3 g (-8%, -17 mg/dL) or 3.8 g (-16%, -31 mg/dL) alone (P < 0.001). The effects of combination therapy on serum HDL cholesterol and triglyceride levels were similar to those for simvastatin alone. Side effects were similar among treatment groups, and there were no clinically important changes in laboratory parameters.

CONCLUSION

Coadministration of colesevelam and simvastatin was effective and well tolerated, providing additive reductions in LDL cholesterol levels compared with either agent alone.

Colesevelam hydrochloride: a non-absorbed, polymeric cholesterol-lowering agent

Colesevelam hydrochloride (formerly known as Cholestagel((R)) and re-named WelCholtrade mark, GelTex Pharmaceuticals, Inc. and Sankyo Parke-Davis) is a new, polymeric, high potency, water-absorbing hydrogel. It has been shown to be a safe and effective cholesterol-lowering agent with a non-systemic mechanism of action, good tolerability and minimal side effects. To date, the lipid-lowering activity of colesevelam has been evaluated in approximately 1400 subjects. Colesevelam reduces low density lipoprotein (LDL)-cholesterol levels, in a dose-dependent manner, by as much as 20% (median) in patients with hypercholesterolaemia. Dosing regimen evaluations indicate that colesevelam is effective at both once per day and twice daily dosing and that concurrent administration of colesevelam with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins), specifically lovastatin, does not alter the absorption of the statin. Combination therapy with HMG-CoA reductase inhibitors, including lovastatin, simvastatin and atorvastatin, produces an additional reduction (8 - 16%) in LDL-cholesterol levels above that seen with the statin alone. The overall incidence of adverse effects with colesevelam alone and in combination with statins is comparable with that seen with placebo. Colesevelam lacks the constipating effect seen with typical bile acid sequestrants, a trait that would be expected to improve compliance with lipid-lowering therapy. Colesevelam, recently approved by the US FDA, represents a valuable non-absorbed alternative in the armamentarium against hypercholesterolaemia, both for monotherapy and combination therapy, as an adjunct to diet and exercise.