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Drugs to avoid in Long QT Syndrome
February 4, 2019
Infective Endocarditis Prophylaxis For Adults
February 11, 2019A number of drugs interact with warfarin. It is therefore important to remember that whenever treatment with any new drug is necessary in patients who are being treated with warfarin, the PT/INR should be monitored approximately every second day during the initial stages of combined drug therapy, with dosage adjustments made as necessary.
Drugs that potentiate or inhibit the anticoagulant effect of warfarin
Potentiate
| Allopurinol | Ethacrynic acid | Nalidixic acid |
| Aminoglycosides | Fenofibrate | Naproxen |
| Anabolic steroids | Fenoprofen | Neomycin |
| Amiodarone | Fluconazole | Norfloxacin |
| Aspirin and other | Fluorouracil | Ofloxacin |
| Non-steroidal anti- | Fluoxetine | Olsalazine |
| Inflammatory drugs | Flutamide | Omeprazole |
| Azithromycin | Fluvastatin | Oral hypoglycemic |
| Carbenicillin | Fluvoxamine | drugs |
| Cefamandole | Glucagon | Oxaprozin |
| Cefazolin | Halothane | Oxymetholone |
| Ceftriaxone | Heparin | Paracetamol |
| Chenodiol | Ibuprofen | Paroxetine |
| Chlormphenicol | Ifosfamide | Phenylbutazone |
| Chloral hydrate | Indomethacin | Phenytoin |
| Chlorpromazine | Isoniazid | Penicillin G, |
| Chlorpropamide | Itraconazole | intravenous |
| Cholestyramine | Ketoconazole | Pentoxifylline |
| Cimetidine | Ketoprofen | Piperacillin |
| Ciprofloxacin | Ketorolac | Piroxicam |
| Clarithromycin | Levamisole | Prednisone |
| Clofibrate | Levothyroxine | Propafenone |
| Cyclophoshamide | Liothyronine | Propoxyphenone |
| Danazol | Lovastatin | Propranolol |
| Dextran | Mefenamic acid | Propylthiouracil |
| Dextrothyroxine | Methimazole | Quinidine |
| Diazoxide | Methyldopa | Quinine |
| Diclofenac | Methylphenidate | Ranitidine |
| Dicumarol | Methylsalicylate Ointment (topical) | Salicylates |
| Diflunisal | Sertraline | Dipyrudamole |
| Metronidazole | Simvastatin | Disulfiram |
| Miconazole | Stanozolol | Doxycycline |
| Moricizine | Streptokinase | Erythromycin |
| Hydrochloride | Sulfamethizole | Moxalactam |
| Sulfinpyrazone | Tissue plasminogen | Valproate |
| Sulfisoxazole | Activator (t-PA) | Vitamin E |
| Sulindac | Tolbutamide | (megadose) |
| Tamoxifen | Tramadol | Zafirlukast |
| Tetracycline | Tricyclic | Zileuton |
| Thyroxine | Antidepressants | Ticarcillin |
| Trimethoprim/ Sulfamethoxazole | Ticlopidine | Urokinase |
Inhibit
| Alcohol | Cyclophosphamide | Pentobarbital |
| Aminoglutethimide | Dicloxacillin | Phenobarbital |
| Amobarbital | Ethchlorvynaol | Phenytoin |
| Atorvastatin | Glutethimide | Prednisone |
| Azathioprine | Griseofulvin | Primidone |
| Barbiturates | Haloperidol | Propylthiouracil |
| Butabarbital | Meprobamate | Ranitidine |
| Butalbital | Methimazole | Rifampin |
| Carbamazepine | 6-mercaptopurine | Secobarbital |
| Chloral hydrate | Moricizine | Spironolactone |
| Chlordiazepoxide | Hydrochloride | Sucralfate |
| Chlorthalidone | Nafcillin | Trazodone |
| Cholestyramine | Oral contraceptives | Vitamin C (high |
| Corticotropin | Paraldehyde | Dose) |
| Cortisone | Penicilin | Vitamin K |