Colesevelam

Colesevelam hydrochloride is a bile acid sequestrant indicated as an adjunct to diet and exercise to: reduce elevated low-density lipoprotein cholesterol (LDL-C) in adults with primary hyperlipidemia ( 1.1 ). reduce LDL-C levels in boys and postmenarchal girls, 10 to 17 years of age, with heterozygous familial hypercholesterolemia (HeFH), unable to reach LDL-C target levels despite an adequate trial of diet and lifestyle modification ( 1.1 ). improve glycemic control in adults with type 2 diabetes mellitus ( 1.2 ). Limitations of Use ( 1.3 ) Do not use for treatment of type 1 diabetes or for diabetic ketoacidosis. Not studied in Fredrickson Type I, III, IV, and V.

1.1 Primary Hyperlipidemia Colesevelam hydrochloride tablets are indicated as an adjunct to diet and exercise to reduce elevated low-density lipoprotein cholesterol (LDL-C) in adults with primary hyperlipidemia. Colesevelam hydrochloride tablets are indicated to reduce LDL-C levels in boys and postmenarchal girls, 10 to 17 years of age, with heterozygous familial hypercholesterolemia (HeFH) who are unable to reach LDL-C target levels despite an adequate trial of dietary therapy and lifestyle modification.

1.2 Type 2 Diabetes Mellitus Colesevelam hydrochloride is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus.

1.3 Limitations of Use Colesevelam hydrochloride should not be used for the treatment of type 1 diabetes or for the treatment of diabetic ketoacidosis. Colesevelam hydrochloride has not been studied in Fredrickson Type I, III, IV, and V dyslipidemias.

Obtain lipid parameters, including serum triglyceride (TG) levels before starting colesevelam hydrochloride ( 2.1 ) The recommended dosage for adults and for boys and postmenarchal girls aged 10 to 17 years with primary hyperlipidemia is 3.75 grams daily. The recommended dosage for adults with type 2 diabetes mellitus is 3.75 grams daily. Colesevelam hydrochloride should be taken as follows ( 2.2 , 2.4 ): Tablets Take 6 tablets once daily or 3 tablets twice daily with a meal and liquid.

2.1 Testing Prior to Initiation of Colesevelam Hydrochloride Tablets Obtain lipid parameters, including triglyceride (TG) levels before starting colesevelam hydrochloride. Colesevelam hydrochloride is contraindicated in patients with TG levels >500 mg/dL [see Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )] .

2.2 Recommended Dosage in Primary Hyperlipidemia and Type 2 Diabetes Mellitus The recommended dosage of colesevelam hydrochloride for adults and for boys and postmenarchal girls aged 10 to 17 years with primary hyperlipidemia is 3.75 grams daily. The recommended dosage of colesevelam hydrochloride for adults with type 2 diabetes mellitus is 3.75 grams daily. Colesevelam hydrochloride should be taken as follows: Take 6 tablets once daily or 3 tablets twice daily. Due to tablet size, colesevelam hydrochloride for oral suspension is recommended for use in the pediatric population.

2.3 Important Dosing Information for Primary Hyperlipidemia Colesevelam hydrochloride can be dosed at the same time as a statin, or colesevelam hydrochloride and the statin can be dosed apart. Monitor lipid levels within 4 to 6 weeks after initiation of colesevelam hydrochloride.

2.4 Administration Instructions Take colesevelam hydrochloride tablets with a meal and liquid. For patients with difficulty swallowing tablets, use colesevelam hydrochloride for oral suspension [see Warnings and Precautions ( 5.2 )].

Colesevelam Hydrochloride Tablets, 625 mg are cream to light yellow colored with or without matte appearance, modified capsule shaped, biconvex, film-coated tablets, imprinted '619' on one side and plain on other side. Tablets: 625 mg ( 3 )

Colesevelam hydrochloride is contraindicated in patients with: Serum TG concentrations > 500 mg/dL [see Warnings and Precautions ( 5.1 )] History of hypertriglyceridemia-induced pancreatitis [see Warnings and Precautions ( 5.1 )] A history of bowel obstruction [see Warnings and Precautions ( 5.2 )] Patients with serum triglyceride levels >500 mg/dL ( 4 ). Patients with a history of hypertriglyceridemia-induced pancreatitis ( 4 ). Patients with a history of bowel obstruction ( 4 ).

5 WARNINGS AND PRECAUTIONS Hypertriglyceridemia and Pancreatitis : Colesevelam hydrochloride can increase TG. Hypertriglyceridemia can cause acute pancreatitis. Monitor lipids, including TG. Instruct patients to discontinue colesevelam hydrochloride and seek prompt medical attention if the symptoms of acute pancreatitis occur ( 5.1 ). Gastrointestinal Obstruction: Cases of bowel obstruction have occurred. Colesevelam hydrochloride is not recommended in patients with gastroparesis, other gastrointestinal motility disorders, and in those who have had major gastrointestinal tract surgery and who may be at risk for bowel obstruction ( 5.2 ). Vitamin K or Fat-Soluble Vitamin Deficiencies: Colesevelam hydrochloride may decrease absorption of fat-soluble vitamins. Patients with a susceptibility to deficiencies of vitamin K (e.g., patients on warfarin, patients with malabsorption syndromes) or other fat-soluble vitamins may be at increased risk. Patients on oral vitamin supplementation should take their vitamins at least 4 hours prior to colesevelam hydrochloride ( 5.3 ). Drug Interactions: Due to the potential for decreased absorption of other drugs that have not been tested for interaction, consider administering at least 4 hours prior to colesevelam hydrochloride ( 5.4 , 7 , 12.3 ).

5.1 Hypertriglyceridemia and Pancreatitis Colesevelam hydrochloride, like other bile acid sequestrants, can increase serum TG concentrations. Hypertriglyceridemia can cause acute pancreatitis. Colesevelam hydrochloride had effects on serum TG (median increase 5% compared to placebo) in trials of patients with primary hyperlipidemia. Obtain lipid parameters, including TG levels, before starting colesevelam hydrochloride and periodically thereafter. Colesevelam hydrochloride is contraindicated in patients with TG levels >500 mg/dL or patients with a history of hypertriglyceridemia-induced pancreatitis [see Contraindications ( 4 )] . Patients with TG levels greater than 300 mg/dL could have greater increases in serum TG levels with colesevelam hydrochloride and may require additional TG monitoring. Instruct patients to discontinue colesevelam hydrochloride and seek prompt medical attention if the symptoms of acute pancreatitis occur (e.g., severe abdominal pain with or without nausea and vomiting). Discontinue colesevelam hydrochloride if TG levels exceed 500 mg/dL [see Adverse Reactions ( 6.1 )] .

5.2 Gastrointestinal Obstruction Postmarketing cases of bowel obstruction have occurred with colesevelam hydrochloride [see Adverse Reactions ( 6.2 )] . Because of its constipating effects, colesevelam hydrochloride is not recommended in patients with gastroparesis, other gastrointestinal motility disorders, and in those who have had major gastrointestinal tract surgery and who may be at risk for bowel obstruction. Colesevelam hydrochloride is contraindicated in patients with a history of bowel obstruction [see Contraindications ( 4 )] . Instruct patients to promptly discontinue colesevelam hydrochloride and seek medical attention if severe abdominal pain or severe constipation occurs. Because of the tablet size, colesevelam hydrochloride tablets can cause dysphagia or esophageal obstruction. For patients with difficulty swallowing tablets, use colesevelam hydrochloride for oral suspension.

5.3 Vitamin K or Fat-Soluble Vitamin Deficiencies Colesevelam hydrochloride may decrease the absorption of fat-soluble vitamins A, D, E, and K. Patients with a susceptibility to deficiencies of vitamin K (e.g., patients on warfarin, patients with malabsorption syndromes) or other fat-soluble vitamins may be at increased risk when taking colesevelam hydrochloride. Patients on oral vitamin supplementation should take their vitamins at least 4 hours prior to colesevelam hydrochloride [see Drug Interactions ( 7.1 )] .

5.4 Drug Interactions Colesevelam hydrochloride reduces gastrointestinal absorption of some drugs. Administer drugs with a known interaction at least 4 hours prior to colesevelam hydrochloride [see Drug Interactions ( 7 )] . Due to the potential for decreased absorption of other drugs that have not been tested for interaction, especially those with a narrow therapeutic index, consider administering at least 4 hours prior to colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] .

Colesevelam hydrochloride reduces gastrointestinal absorption of some drugs. Administer drugs with a known interaction at least 4 hours prior to colesevelam hydrochloride [see Drug Interactions ( 7 )] . Due to the potential for decreased absorption of other drugs that have not been tested for interaction, especially those with a narrow therapeutic index, consider administering at least 4 hours prior to colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] .

Concomitant use with colesevelam hydrochloride may decrease the exposure of the following drugs: Drugs with a narrow therapeutic index (e.g., cyclosporine), phenytoin, thyroid hormone replacement therapy, warfarin, oral contraceptives containing ethinyl estradiol and norethindrone, olmesartan medoxomil, and sulfonylureas (glimepiride, glipizide, glyburide). Administer these drugs 4 hours prior to colesevelam hydrochloride. For patients on warfarin, monitor International Normalized Ratio (INR) frequently during initiation then periodically ( 7.1 ). Concomitant use with colesevelam hydrochloride may increase the exposure of the following drugs: Metformin extended release. Monitor patients' glycemic control ( 7.2 ).

7.1 Colesevelam Hydrochloride Drug Interactions that Decrease the Exposure of the Concomitant Medication Table 4 includes a list of drugs that decrease exposure of the concomitant medication when administered concomitantly with colesevelam hydrochloride and instructions for preventing or managing them. Table 4 Colesevelam Hydrochloride Drug Interactions that Decrease the Exposure of the Concomitant Medication Drugs with a Narrow Therapeutic Index Clinical Impact Concomitant use with colesevelam hydrochloride may decrease the exposure of the narrow therapeutic index drug. In vivo drug interactions studies showed a decrease in exposure of cyclosporine when coadministered with colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] . Intervention Administer the narrow therapeutic index drug at least 4 hours prior to colesevelam hydrochloride. Monitor drug levels when appropriate. Examples Cyclosporine Phenytoin Clinical Impact There have been postmarketing reports of increased seizure activity or decreased phenytoin levels in patients receiving phenytoin [see Adverse Reactions ( 6.2 )] . Intervention Administer phenytoin 4 hours prior to colesevelam hydrochloride. Thyroid Hormone Replacement Therapy Clinical Impact In vivo drug interactions studies showed a decrease in exposure of levothyroxine when coadministered with colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] . There have been postmarketing reports of elevated thyroid-stimulating hormone (TSH) in patients receiving thyroid hormone replacement therapy [see Adverse Reactions ( 6.2 )] . Intervention Administer thyroid hormone replacement therapy 4 hours prior to colesevelam hydrochloride. Warfarin Clinical Impact There have been postmarketing reports of reduced INR in patients receiving warfarin therapy [see Adverse Reactions ( 6.2 )] . Intervention Monitor INR frequently during colesevelam hydrochloride initiation then periodically thereafter. Oral Contraceptives Containing Ethinyl Estradiol and Norethindrone Clinical Impact In vivo drug interactions studies showed a decrease in exposure of ethinyl estradiol and norethindrone when coadministered with colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] . Intervention Administer oral contraceptives containing ethinyl estradiol and norethindrone 4 hours prior to colesevelam hydrochloride. Olmesartan Medoxomil Clinical Impact In vivo drug interactions studies showed a decrease in olmesartan medoxomil when coadministered with colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] . Intervention Administer olmesartan medoxomil 4 hours prior to colesevelam hydrochloride. Sulfonylureas Clinical Impact In vivo drug interactions studies showed a decrease in sulfonylureas when coadministered with colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] . Intervention Administer sulfonylureas 4 hours prior to colesevelam hydrochloride. Examples Glimepiride, glipizide, and glyburide Oral Vitamin Supplements Clinical Impact Colesevelam hydrochloride may decrease the absorption of fat-soluble vitamins A, D, E, and K [see Warnings and Precautions ( 5.3 )] . Intervention Patients on oral vitamin supplementation should take their vitamins at least 4 hours prior to colesevelam hydrochloride.

7.2 Colesevelam Hydrochloride Drug Interactions that Increase the Exposure of the Concomitant Medication Table 5 Colesevelam hydrochloride Drug Interactions that Increase the Exposure of the Concomitant Medication Metformin Extended-Release (ER) Clinical Impact In vivo drug interactions studies showed an increase in metformin extended release (ER) when coadministered with colesevelam hydrochloride [see Clinical Pharmacology ( 12.3 )] . Intervention Monitor patients' glycemic control.

Colesevelam hydrochloride is not absorbed and the risk of systemic toxicity is low. Excessive doses of colesevelam hydrochloride may cause more severe local gastrointestinal effects (e.g., constipation).

Risk Summary Colesevelam hydrochloride is not absorbed systemically following oral administration, and maternal use is not expected to result in fetal exposure to the drug. Limited available data on the use of colesevelam hydrochloride are insufficient to determine a drug-associated risk of major congenital malformations or miscarriage. In animal reproduction studies, no evidence of either maternal or fetal toxicity was found in rats or rabbits exposed to colesevelam hydrochloride during the period of fetal organogenesis at 8 and 5 times, respectively, the maximum recommended human dose (MRHD) of 3.75 g/day, based on body surface area (mg/m 2 ). No adverse effects on offspring survival and development were observed in rats administered 5 times the MRHD (see Data) . Colesevelam hydrochloride may decrease the absorption of fat-soluble vitamins [see Warnings and Precautions ( 5.3 )] . There are no data available on the effect of colesevelam hydrochloride on the absorption of fat-soluble vitamins in pregnant women. If the patient becomes pregnant while taking colesevelam hydrochloride, the patient should be advised of the lack of known clinical benefit with continued use during pregnancy. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the US general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20% respectively. Data Human Data There are no adequate and well-controlled studies of colesevelam hydrochloride use in pregnant women. In the postmarketing setting there have been infrequent reports of pregnancy with use of colesevelam hydrochloride and a causal association with congenital anomalies has not been established. Animal Data In pregnant rats given dietary doses of 0.3 g/kg/day, 1 g/kg/day, 3 g/kg/day colesevelam hydrochloride from gestation days 7 through 17, no teratogenic effects were observed. Exposures at 3 g/kg/day were 8 times the human exposure at 3.75 g/day MRHD, based on body surface area (mg/m 2 ). In pregnant rabbits given oral gavage doses of 0.1 g/kg/day, 0.5 g/kg/day, 1 g/kg/day colesevelam hydrochloride from gestation days 6 through 18, no teratogenic effects were observed. Exposures at 1 g/kg/day were 5 times the human exposure at 3.75 g/day MRHD, based on body surface area (mg/m 2 ). In pregnant rats given oral gavage doses of 0.1 g/kg/day, 0.3 g/kg/day, 1 g/kg/day colesevelam hydrochloride from gestation day 6 through lactation day 21 (weaning), no adverse effects on survival and development were observed. Exposures at 1 g/kg/day were 5 times the human exposure at 3.75 g/day MRHD, based on body surface area (mg/m 2 ).

Primary Hyperlipidemia The safety and effectiveness of Colesevelam hydrochloride to reduce LDL-C levels in boys and postmenarchal girls 10 to 17 years of age with HeFH who are unable to reach LDL-C target levels despite an adequate trial of dietary therapy and lifestyle modification have been established. Use of Colesevelam hydrochloride for this indication is supported by a study in 129 Colesevelam hydrochloride -treated pediatric patients aged 10 to 17 years with HeFH [see Clinical Studies ( 14.1 )] . Adverse reactions commonly observed in pediatric patients compared to placebo, but not in adults, included headache (3.9%), creatine phosphokinase increase (2.3%), and vomiting (2.3%) [see Adverse Reactions ( 6.1 )] . There were no significant effects on fat-soluble vitamin levels or clotting factors in the adolescent boys or girls relative to placebo. Due to Colesevelam hydrochloride tablet size, Colesevelam hydrochloride for oral suspension is recommended for use in the pediatric population [see Dosage and Administration ( 2.2 , 2.4 )] . The safety and effectiveness of Colesevelam hydrochloride in pediatric patients with HeFH less than 10 years of age or in premenarchal females have not been established. Type 2 Diabetes Mellitus The safety and effectiveness of colesevelam hydrochloride to improve glycemic control in pediatric patients with type 2 diabetes mellitus have not been established. Effectiveness was not demonstrated in a 6-month, adequate and well-controlled study conducted in 141 colesevelam hydrochloride -treated pediatric patients aged 10 to 17 years with type 2 diabetes mellitus.

Primary Hyperlipidemia Of the 1350 patients enrolled in the hyperlipidemia clinical studies, 349 (26%) were ≥65 years old, and 58 (4%) were ≥75 years old. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Type 2 Diabetes Mellitus Of the 2048 patients enrolled in the six diabetes studies, 397 (19%) were ≥65 years old, and 36 (2%) were ≥75 years old. In these trials, colesevelam hydrochloride 3.8 g/day or placebo was added onto background anti-diabetic therapy. No overall differences in safety or effectiveness were observed between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

Colesevelam hydrochloride is a non-absorbed, polymeric, lipid-lowering and glucose-lowering agent for oral administration. Colesevelam hydrochloride is a high-capacity bile acid-binding molecule. Colesevelam hydrochloride is a polymer with off-white to light yellow color powder, which is insoluble in water and any organic solvent. Colesevelam hydrochloride is poly (allylamine hydrochloride) cross-linked with epichlorohydrin and alkylated with 1-bromodecane and (6-bromohexyl)-trimethylammonium bromide. The chemical name (IUPAC) of colesevelam hydrochloride is allylamine polymer with 1-chloro-2,3-epoxypropane, [6-(allylamino)-hexyl]trimethylammonium chloride and N-allyldecylamine, hydrochloride. The chemical structure of colesevelam hydrochloride is represented by the following formula: wherein (a) represents allyl amine monomer units that have not been alkylated by either of the 1-bromodecane or (6-bromohexyl)-trimethylammonium bromide alkylating agents or cross-linked by epichlorohydrin; (b) represents allyl amine units that have undergone cross- linking with epichlorohydrin; (c) represents allyl amine units that have been alkylated with a decyl group; (d) represents allyl amine units that have been alkylated with a (6-trimethylammonium) hexyl group, and m represents a number ≥ 100 to indicate an extended polymer network. A small amount of the amines are dialkylated and are not depicted in the formula above. No regular order of the groups is implied by the structure; cross-linking and alkylation are expected to occur randomly along the polymer chains. A large amount of the amines are protonated. The polymer is depicted in the hydrochloride form; a small amount of the halides are bromide. Colesevelam hydrochloride is hydrophilic and insoluble in water. Colesevelam hydrochloride tablet contains 625 mg colesevelam hydrochloride. In addition, each tablet contains the following inactive ingredients: colloidal silicon dioxide, crospovidone, hypromellose, iron oxide yellow, iron oxide red, magnesium stearate, methacrylic acid copolymer, microcrystalline cellulose, povidone, polyethylene glycol, polyvinyl alcohol, talc, titanium dioxide, sodium bicarbonate. The tablet is printed with black pharmaceutical ink which contains ammonium hydroxide, ferrosoferric oxide, propylene glycol and shellac (< 5 calories per 6 tablets). Image

12.1 Mechanism of Action Primary Hyperlipidemia Colesevelam hydrochloride, the active pharmaceutical ingredient in colesevelam hydrochloride, is a non-absorbed, lipid-lowering polymer that binds bile acids in the intestine, impeding their reabsorption. As the bile acid pool becomes depleted, the hepatic enzyme, cholesterol 7-α-hydroxylase, is upregulated, which increases the conversion of cholesterol to bile acids. This causes an increased demand for cholesterol in the liver cells, resulting in the dual effect of increasing transcription and activity of the cholesterol biosynthetic enzyme, HMG-CoA reductase, and increasing the number of hepatic LDL receptors. These compensatory effects result in increased clearance of LDL-C from the blood, resulting in decreased serum LDL-C levels. Serum TG levels may increase or remain unchanged. Type 2 Diabetes Mellitus The mechanism by which Colesevelam hydrochloride improves glycemic control is unknown.

12.2 Pharmacodynamics A maximum therapeutic response to the lipid-lowering effects of colesevelam hydrochloride was achieved within 2 weeks and was maintained during long-term therapy. In the diabetes clinical studies, a therapeutic response to Colesevelam hydrochloride, as reflected by a reduction in HbA1c, was initially noted following 4-6 weeks of treatment and reached maximal or near-maximal effect after 12-18 weeks of treatment.

12.3 Pharmacokinetics Absorption Colesevelam hydrochloride is a hydrophilic, water-insoluble polymer that is not hydrolyzed by digestive enzymes and is not absorbed. Distribution Colesevelam hydrochloride is not absorbed, and therefore, its distribution is limited to the gastrointestinal tract. Elimination Metabolism Colesevelam hydrochloride is not metabolized systemically and does not interfere with systemic drug-metabolizing enzymes such as cytochrome P-450. Excretion In 16 healthy volunteers, an average of 0.05% of administered radioactivity from a single 14 C-labeled colesevelam hydrochloride dose was excreted in the urine. Drug Interaction Studies Drug interactions between colesevelam and concomitantly administered drugs were screened through in vitro studies and confirmed in in vivo studies. In vitro studies demonstrated that cephalexin, metformin, and ciprofloxacin had negligible binding to colesevelam hydrochloride. Therefore, an in vivo pharmacokinetic interaction of colesevelam hydrochloride with these drugs is unlikely. Colesevelam hydrochloride was found to have no significant effect on the bioavailability of aspirin, atenolol, digoxin, enalapril, fenofibrate, lovastatin, metoprolol, phenytoin, pioglitazone, quinidine, rosiglitazone, sitagliptin, valproic acid, and warfarin. The results of additional in vivo drug interactions of colesevelam hydrochloride are presented in Table 6. Table 6 Mean Change in Drug Exposure (AUC 0-∞ and C max ) when Administered with Colesevelam Hydrochloride(3.75 g) * * With verapamil, the dose of colesevelam hydrochloride was 4.5 g † Oral contraceptive containing norethindrone and ethinyl estradiol N/A – Not Available Drug Dose Coadministered 1 hr prior to Colesevelam Hydrochloride 4 hr prior to Colesevelam Hydrochloride AUC 0-∞ C max AUC 0-∞ C max AUC 0-∞ C max Cyclosporine 200 mg -34% -44% N/A N/A N/A N/A Ethinyl Estradiol † 0.035 mg -24% -24% -18% -1% -12% 0% Glimepiride 4 mg -18% -8% N/A N/A -6% 3% Glipizide 20 mg -12% -13% N/A N/A -4% 0% Glyburide 3 mg -32% -47% -20% -15% -7% 4% Levothyroxine 600 μg -22% -33% 6% -2% 1% 8% Metformin ER 1500 mg 44% 8% N/A N/A N/A N/A Norethindrone † 1 mg -1% -20% 5% -3% 6% 7% Olmesartan Medoxomil 40 mg -39% -28% N/A N/A -15% -4% Repaglinide 2 mg -7% -19% -6% -1% N/A N/A Verapamil Sustained-Release 240 mg -31% -11% N/A N/A N/A N/A

Primary Hyperlipidemia Colesevelam hydrochloride, the active pharmaceutical ingredient in colesevelam hydrochloride, is a non-absorbed, lipid-lowering polymer that binds bile acids in the intestine, impeding their reabsorption. As the bile acid pool becomes depleted, the hepatic enzyme, cholesterol 7-α-hydroxylase, is upregulated, which increases the conversion of cholesterol to bile acids. This causes an increased demand for cholesterol in the liver cells, resulting in the dual effect of increasing transcription and activity of the cholesterol biosynthetic enzyme, HMG-CoA reductase, and increasing the number of hepatic LDL receptors. These compensatory effects result in increased clearance of LDL-C from the blood, resulting in decreased serum LDL-C levels. Serum TG levels may increase or remain unchanged. Type 2 Diabetes Mellitus The mechanism by which Colesevelam hydrochloride improves glycemic control is unknown.

A maximum therapeutic response to the lipid-lowering effects of colesevelam hydrochloride was achieved within 2 weeks and was maintained during long-term therapy. In the diabetes clinical studies, a therapeutic response to Colesevelam hydrochloride, as reflected by a reduction in HbA1c, was initially noted following 4-6 weeks of treatment and reached maximal or near-maximal effect after 12-18 weeks of treatment.

Absorption Colesevelam hydrochloride is a hydrophilic, water-insoluble polymer that is not hydrolyzed by digestive enzymes and is not absorbed. Distribution Colesevelam hydrochloride is not absorbed, and therefore, its distribution is limited to the gastrointestinal tract. Elimination Metabolism Colesevelam hydrochloride is not metabolized systemically and does not interfere with systemic drug-metabolizing enzymes such as cytochrome P-450. Excretion In 16 healthy volunteers, an average of 0.05% of administered radioactivity from a single 14 C-labeled colesevelam hydrochloride dose was excreted in the urine. Drug Interaction Studies Drug interactions between colesevelam and concomitantly administered drugs were screened through in vitro studies and confirmed in in vivo studies. In vitro studies demonstrated that cephalexin, metformin, and ciprofloxacin had negligible binding to colesevelam hydrochloride. Therefore, an in vivo pharmacokinetic interaction of colesevelam hydrochloride with these drugs is unlikely. Colesevelam hydrochloride was found to have no significant effect on the bioavailability of aspirin, atenolol, digoxin, enalapril, fenofibrate, lovastatin, metoprolol, phenytoin, pioglitazone, quinidine, rosiglitazone, sitagliptin, valproic acid, and warfarin. The results of additional in vivo drug interactions of colesevelam hydrochloride are presented in Table 6. Table 6 Mean Change in Drug Exposure (AUC 0-∞ and C max ) when Administered with Colesevelam Hydrochloride(3.75 g) * * With verapamil, the dose of colesevelam hydrochloride was 4.5 g † Oral contraceptive containing norethindrone and ethinyl estradiol N/A – Not Available Drug Dose Coadministered 1 hr prior to Colesevelam Hydrochloride 4 hr prior to Colesevelam Hydrochloride AUC 0-∞ C max AUC 0-∞ C max AUC 0-∞ C max Cyclosporine 200 mg -34% -44% N/A N/A N/A N/A Ethinyl Estradiol † 0.035 mg -24% -24% -18% -1% -12% 0% Glimepiride 4 mg -18% -8% N/A N/A -6% 3% Glipizide 20 mg -12% -13% N/A N/A -4% 0% Glyburide 3 mg -32% -47% -20% -15% -7% 4% Levothyroxine 600 μg -22% -33% 6% -2% 1% 8% Metformin ER 1500 mg 44% 8% N/A N/A N/A N/A Norethindrone † 1 mg -1% -20% 5% -3% 6% 7% Olmesartan Medoxomil 40 mg -39% -28% N/A N/A -15% -4% Repaglinide 2 mg -7% -19% -6% -1% N/A N/A Verapamil Sustained-Release 240 mg -31% -11% N/A N/A N/A N/A

, Mutagenesis, Impairment of Fertility Carcinogenesis A 104-week carcinogenicity study with colesevelam hydrochloride was conducted in CD-1 mice, at oral dietary doses up to 3 g/kg/day. This dose was approximately 50 times the maximum recommended human dose of 4.5 g/day, based on body weight, mg/kg. There were no significant drug-induced tumor findings in male or female mice. In a 104-week carcinogenicity study with colesevelam hydrochloride in Harlan Sprague-Dawley rats, a statistically significant increase in the incidence of pancreatic acinar cell adenoma was seen in male rats at doses > 1.2 g/kg/day (approximately 20 times the maximum human dose, based on body weight, mg/kg) (trend test only). A statistically significant increase in thyroid C-cell adenoma was seen in female rats at 2.4 g/kg/day (approximately 40 times the maximum human dose, based on body weight, mg/kg). Mutagenesis Colesevelam hydrochloride and 4 degradants present in the drug substance have been evaluated for mutagenicity in the Ames test and a mammalian chromosomal aberration test. The 4 degradants and an extract of the parent compound did not exhibit genetic toxicity in an in vitro bacterial mutagenesis assay in s. typhimurium and E. coli (Ames assay) with or without rat liver metabolic activation. An extract of the parent compound was positive in the Chinese Hamster Ovary (CHO) cell chromosomal aberration assay in the presence of metabolic activation and negative in the absence of metabolic activation. The results of the CHO cell chromosomal aberration assay with 2 of the 4 degradants, decylamine HCl and aminohexyltrimethyl ammonium chloride HCl, were equivocal in the absence of metabolic activation and negative in the presence of metabolic activation. The other 2 degradants, didecylamine HCl and 6-decylamino-hexyltrimethyl ammonium chloride HCl, were negative in the presence and absence of metabolic activation. Impairment of Fertility Colesevelam hydrochloride did not impair fertility in rats at doses up to 3 g/kg/day (approximately 50 times the maximum human dose, based on body weight, mg/kg).

17 PATIENT COUNSELING INFORMATION Hypertriglyceridemia and Pancreatitis Inform patients that colesevelam hydrochloride may increase their serum triglycerides which can lead to hypertriglyceridemia and pancreatitis. Instruct patients to discontinue colesevelam hydrochloride and seek prompt medical attention if the symptoms of acute pancreatitis occur (e.g., severe abdominal pain with or without nausea and vomiting) [see Warnings and Precautions ( 5.1 )] . Gastrointestinal Inform patients that colesevelam hydrochloride may cause bowel obstruction. Instruct patients to promptly discontinue colesevelam hydrochloride and seek medical attention if severe abdominal pain or severe constipation occurs [see Warnings and Precautions ( 5.2 )] . Drug and Vitamin Interactions Advise patients that colesevelam hydrochloride has drug interactions and colesevelam hydrochloride may decrease the absorption of fat-soluble vitamins A, D, E, and K. Instruct patients to take oral vitamins at least 4 hours prior to colesevelam hydrochloride. Instruct patients to inform their physician about all the drugs and vitamins that they are prescribed or take over the counter [see Warnings and Precautions ( 5.3 ) and Drug Interactions ( 7 )] . Hypertriglyceridemia and Cardiovascular Disease Inform patients that colesevelam hydrochloride may increase serum triglycerides and that the long-term effect of hypertriglyceridemia on the risk of coronary artery disease is uncertain [see Warnings and Precautions ( 5.1 )] . Administration [see Dosage and Administration ( 2.2 , 2.4 )] Advise patients to take colesevelam hydrochloride tablets with a meal and liquid. Inform patients that colesevelam hydrochloride tablets can be taken as 6 tablets once daily or 3 tablets twice daily. Females of Reproductive Potential Advise females of reproductive potential that colesevelam hydrochloride may reduce the effectiveness of oral contraceptives, and to take oral contraceptives at least 4 hours before taking colesevelam hydrochloride [see Drug Interactions ( 7.1 ) and Use in Specific Populations ( 8.3 )] . Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.