Drug Interactions of Lipid Lowering Drugs (Part 4):

Drug Interactions of Niacin:

More presentations from Naina Mohamed Pakkir Maideen

©   Niacin is used to treat high cholesterol and Pellagra.

©   Mechanism of Action of Niacin:

©   Niacin can interact majorly with Statins (Simvastatin, Rosuvastatin, Atorvastatin, Lovastatin, etc) and moderately with Warfarin.

©   If coadministration of Niacin and Statins is required, monitor the patient for signs and symptoms of myopathy or rhabdomyolysis (Muscle pain, Tenderness, or weakness). Periodic creatine kinase (CK) determinations may be advisable.

©   More frequent monitoring of INR and/or prothrombin time is recommended, if concomitant therapy is required.

©   The occurrence of significant morbidity and mortality can be reduced by minimizing the risk for drug interactions.

©   The hyperlipidemic patients should bring a list of all the drugs they are taking including prescription drugs, over-the-counter drugs, and any supplements, herbal or otherwise, during their visit to the Doctor or Pharmacist.

©   The risk of adverse effects could be reduced and the quality of life for patients improved by healthcare professionals through the screening, education, and follow up on suspected drug interactions.

©   If possible, the hyperlipidemic patients are recommended to fill all their prescriptions at one pharmacy.

Drug Interactions of Lipid Lowering Drugs (Part 3):

Drug Interactions of Bile Acid Sequestrants:

Drug Interactions of Bile acid sequestrants

More presentations from Naina Mohamed Pakkir Maideen

©   Bile Acid Sequestrants or Ion-exchange resins include Cholestyramine, Colestipol, and Colesevelam.

©   Bile Acid Sequestrants are used occasionally to treat Hyperlipidemia, as an adjunct to the statins. Bile acid sequestrants are also used as the principal therapy for bile acid-induced diarrhea.

©   Bile Acid Sequestrants interact majorly with drugs such as Deferasirox, Bezafibrate, Mycophenolate, etc.

©   Monitor serum ferritin levels and clinical response, when Bile acid sequestrants and Deferasirox are coadministered.

©   Separate the administration of Bezafibrate and Bile acid sequestrants by at least 2 hours.

©   It is recommended to avoid the coadministration of Bile acid sequestrants and Mycophenolate.

©   The patients are advised to take Pravastatin 1 hour before or 4 hours after Colesevelam.

©   The interaction between Colesevelam and Levothyroxine can be avoided by separating the administration of the two drugs by at least 4 hours.

©   The occurrence of significant morbidity and mortality can be reduced by minimizing the risk for drug interactions.

©   The hyperlipidemic patients should bring a list of all the drugs they are taking including prescription drugs, over-the-counter drugs, and any supplements, herbal or otherwise, during their visit to the Doctor or Pharmacist.

©   The risk of adverse effects could be reduced and the quality of life for patients improved by healthcare professionals through the screening, education, and follow up on suspected drug interactions.

©   If possible, the hyperlipidemic patients are recommended to fill all their prescriptions at one pharmacy.

Drug Interactions of Lipid Lowering Drugs (Part 2):

Drug Interactions of Fibrates:

More presentations from Naina Mohamed Pakkir Maideen

©   Fibrates (Fibric acid derivatives) include Gemfibrozil, Clofibrate, Ciprofibrate, Fenofibrate and Bezafibrate.

©   Fibrates are used as the firstline drugs to treat primary hypertriglyceridemia.

©   Mechanism of Action of Fibrates:

Mechanism of action of Fibrates

©   It is contraindicated to use Ciprofibrate with other Fibrates and Gemfibrozil with Repaglinide, Simvastatin or Dasabuvir, concomitantly.

©   Fibrates can interact majorly with drugs such as Ezetimibe and Sulfonylurea Antidiabetics (Glyburide, Glipizide, Glimepiride, etc).

©   The major interactions of Gemfibrozil include Other Statins (Lovastatin, Atorvastatin, Fluvastatin, Pravastatin) and Colchicine.

©   The concomitant use of Fibrates and Ciprofibrate is contraindicated due to an increased risk of rhabdomyolysis and myoglobulinuria.

©   To avoid cholelithiasis, the coadministration of Ezetimibe and fibrates (except Fenofibrate), is not recommended.

©   Close monitoring of blood glucose is recommended, if Fibrates and Sulfonylurea Antidiabetics (Glyburide, Glipizide, Glimepiride, etc) are used concurrently.

©   Due to elevated risk of hypoglycemia, the combined use of Gemfibrozil and Repaglinide, is contraindicated.

©   The concomitant use of Gemfibrozil and Simvastatin may increase the risk of developing myopathy or rhabdomyolysis and is contraindicated.

©   Concomitant use of Dasabuvir and Gemfibrozil is contraindicated due to a 10-fold increase in dasabuvir exposure and an increased risk of QT prolongation.

©   The concomitant use of Gemfibrozil and Statins should be avoided, if possible.

©   Patients receiving Gemfibrozil and Colchicine should be monitored closely for signs and symptoms of myopathy or rhabdomyolysis.

©   Concomitant use of Fenofibrate and Anticoagulants,  requires the monitoring of INR value.

©   The interaction between Bezafibrate and Bile acid Sequestrants (Cholestyramine, Colestipol, Colesevelam)  can be avoided by separating the administration of the two drugs by at least 2 hours.

©   The occurrence of significant morbidity and mortality can be reduced by minimizing the risk for drug interactions.

©   The hyperlipidemic patients should bring a list of all the drugs they are taking including prescription drugs, over-the-counter drugs, and any supplements, herbal or otherwise, during their visit to the doctor or pharmacist.

©   The risk of adverse effects could be reduced and the quality of life for patients improved by healthcare professionals through the screening, education, and follow up on suspected drug interactions.

©   If possible, the hyperlipidemic patients are recommended to fill all their prescriptions at one pharmacy.

Drug Interactions of Lipid Lowering Drugs (Part 1):

Drug Interactions of Statins:

More presentations from Naina Mohamed Pakkir Maideen

©   Statins (HMG CoA Reductase Inhibitors) include Simvastatin, Lovastatin, Atorvastatin, Rosuvastatin, Pravastatin, Fluvastatin and Pitavastatin.

©   Statins are commonly used to reduce LDL cholesterol.

©   Mechanism of Action of Statins:

©   Lipophilic statins like Simvastatin, Lovastatin and Atorvastatin are the substrates for cytochrome P (450) 3A4 enzyme and hence they are involved in many Adverse drug interactions (Myotoxicity). Potent CYP3A4 inhibitors such as Azole Antifungals, Macrolide Antibiotics, Antivirals (Protease Inhibitors), Fibrates, Potent CYP3A4 Inhibitors, CYP3A4 Inducers, Warfarin, Niacin, Colchicine, Daptomycin and Grapefruit Juice can significantly increase the plasma concentrations and toxicity of Simvastatin, Lovastatin and Atorvastatin.
©   Lipophilic Fluvastatin is metabolized by CYP2C9 and is less prone to pharmacokinetic interactions.
©   Hydrophilic statins such as Pravastatin and Rosuvastatin are not significantly metabolized by cytochrome P (450) enzymes. 

©   Concomitant use of Statins (Simvastatin or Lovastatin) and Azole antifungals (Fluconazole, Itraconazole, Ketoconazole, Posaconazole, Voriconazole and Miconazole), Macrolide Antibiotics (Erythromycin, Telithromycin and Clarithromycin), Protease Inhibitors (Lopinavir, Ritonavir, Darunavir, Saquinavir, Indinavir, Fosamprenavir, Nelfinavir, Ritonavir, Atazanavir, etc), Fibrates (Gemfibrozil, Ciprofibrate, Bezafibrate, Clofibrate, etc) or Potent CYP3A4 Inhibitors (Cyclosporine, Nefazodone, Mifepristone, Cobicistat, Idelalisib, Mibefradil) is Contraindicated.

©   Monitor the patients for signs and symptoms of myopathy or rhabdomyolysis (muscle pain, tenderness, or weakness) and creatine kinase (CK) levels, if other statins such as Atorvastatin, Fluvastatin or Cerivastatin used along with Azole antifungals, Macrolide antibiotics, Protease inhibitors, Fibrates or Potent CYP3A4 Inhibitors.

©   Monitoring for signs and symptoms of myopathy or rhabdomyolysis (muscle pain, tenderness, or weakness) and creatine kinase (CK) levels is recommended when Statins and Weak CYP3A4 Inhibitors (Verapamil, Diltiazem, Amiodarone, Ranolazine, Conivaptan, Nilotinib, Ceritinib, Delavirdine), Warfarin, Niacin, Colchicine, Daptomycin or Grapefruit Juice co-administered.

©   The International normalized ratio (INR) should be closely monitored in patients taking statins and Warfarin.

©   Adjust the dose of statins, if statins and CYP3A4 inducers (Carbamazepine, Eslicarbazepine, Dabrafenib) are used concomitantly.

©   Concomitant use of Simvastatin and Ciprofloxacin, Amlodipine, Tadalafil or Cranberry juice warrants the monitoring of signs and symptoms of myopathy or rhabdomyolysis.

©   Statins are contraindicated during Pregnancy.

©   Nursing mothers should avoid using statins.

©   To reduce the rate of interactions, consider substituting CYP3A4-substrate statins (Simvastatin, Lovastatin and Atorvastatin) with other statin such as pravastatin which is not metabolized by CYP 3A4, if possible.

©   The patients with hyperlipidemia should bring a list of all the drugs they are taking including prescription drugs, over the counter (OTC) drugs, and any supplements during their visit to the Doctor or Pharmacist.