Colestid (Colestipol Hydrochloride) - Drug Interactions, Contraindications, Overdosage, etc

DRUG INTERACTIONS

Drug Interactions

Since colestipol hydrochloride is an anion exchange resin, it may have a strong affinity for anions other than the bile acids. In vitro studies have indicated that colestipol hydrochloride binds a number of drugs. Therefore, COLESTID and FLAVORED COLESTID resin may delay or reduce the absorption of concomitant oral medication. The interval between the administration of COLESTID and FLAVORED COLESTID and any other medication should be as long as possible. Patients should take other drugs at least one hour before or four hours after COLESTID and FLAVORED COLESTID to avoid impeding their absorption.

Repeated doses of colestipol hydrochloride given prior to a single dose of propranolol in human trials have been reported to decrease propranolol absorption. However, in a follow-up study in normal subjects, single dose administration of colestipol hydrochloride and propranolol and twice-a-day administration for 5 days of both agents did not effect the extent of propranolol absorption, but had a small yet statistically significant effect on its rate of absorption; the time to reach maximum concentration was delayed 30 minutes. Effects on the absorption of other beta-blockers have not been determined. Therefore, patients on propranolol should be observed when COLESTID or FLAVORED COLESTID is either added or deleted from a therapeutic regimen.

Studies in humans show that the absorption of chlorothiazide as reflected in urinary excretion is markedly decreased even when administered one hour before colestipol hydrochloride. The absorption of tetracycline, furosemide, penicillin G, hydrochlorothiazide, and gemfibrozil was significantly decreased when given simultaneously with colestipol hydrochloride; these drugs were not tested to determine the effect of administration one hour before colestipol hydrochloride.

No depressant effect on blood levels in humans was noted when colestipol hydrochloride was administered with any of the following drugs: aspirin, clindamycin, clofibrate, methyldopa, nicotinic acid (niacin), tolbutamide, phenytoin or warfarin. Particular caution should be observed with digitalis preparations since there are conflicting results for the effect of colestipol hydrochloride on the availability of digoxin and digitoxin. The potential for binding of these drugs if given concomitantly is present. Discontinuing colestipol hydrochloride could pose a hazard to health if a potentially toxic drug that is significantly bound to the resin has been titrated to a maintenance level while the patient was taking colestipol hydrochloride.

Bile acid binding resins may also interfere with the absorption of oral phosphate supplements and hydrocortisone.

OVERDOSAGE

Overdosage of COLESTID Granules or FLAVORED COLESTID Granules has not been reported. Should overdosage occur, however, the chief potential harm would be obstruction of the gastrointestinal tract. The location of such potential obstruction, the degree of obstruction and the presence or absence of normal gut motility would determine treatment.

CONTRAINDICATIONS

COLESTID Granules and FLAVORED COLESTID Granules are contraindicated in those individuals who have shown hypersensitivity to any of its components.

REFERENCES

1. Summary of the Second Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel II). JAMA 269(23):3015–3023, 1993.
2. Lipid Metabolism-Atherogenesis Branch, National Heart, Lung, and Blood Institute, Bethesda, MD: The Lipid Research Clinics Coronary Primary Prevention Trial Results. I. Reduction in Incidence of Coronary Heart Disease. JAMA 251:351–364, 1984.
3. Parra HJ, et al. Differential electroimmunoassay of human LpA-I lipoprotein particles on ready-to-use plates. Clin. Chem. 36(8):1431–1435, 1990.
4. Barbaras R, et al. Cholesterol efflux from cultured adipose cells is mediated by LpAI particles but not by LpAI:AII particles. Biochem. Biophys. Res. Comm. 142(1):63–69, 1987.
5. Kane JP, et al. Normalization of low-density-lipoprotein levels in heterozygous familial hypercholesterolemia with a combined drug regimen. N Engl. J. Med. 304:251–258, 1981.
6. Illingworth DR, et al. Colestipol plus nicotinic acid in treatment of heterozygous familial hypercholesterolemia. Lancet 1:296–298, 1981.
7. Kuo PT, et al. Familial type II hyperlipoproteinemia with coronary heart disease: Effect of diet-colestipol-nicotinic acid treatment. Chest 79:286–291, 1981.
8. Blankenhorn DH, et al. Beneficial Effects of Combined Colestipol-Niacin Therapy on Coronary Atherosclerosis and Coronary Venous Bypass Grafts. JAMA 257(23):3233–3240, 1987.
9. Cashin-Hemphill L, et al. Beneficial Effects of Colestipol-Niacin on Coronary Atherosclerosis: A 4-Year Follow-up. JAMA 264:3013–3017, 1990.
10. Brown G, et al. Regression of Coronary Artery Disease as a Result of Intensive Lipid-Lowering Therapy in Men with High Levels of Apolipoprotein B. N Engl, J. Med 323:1289–1298, 1990.
11. Kane JP, et al. Regression of Coronary Atherosclerosis During Treatment of Familial Hypercholesterolemia with Combined Drug Regimens. JAMA 264:3007–3012, 1990.

Rx only

 LAB-0054-2.0