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Seventy percent of us take at least one medication every day, according to a study published in the journal Mayo Clinic Proceedings, more than half take at least two, and 20 percent – a whopping one in five – take five or more medications a day. Antibiotics, antidepressants, and narcotic pain relievers are the most common drugs.
All drugs have risks. And one of the most dangerous is an interaction with other medications. Even though pharmacies use software that automatically flags drugs for interactions, it doesn’t tell the pharmacist which interactions are “clinically significant,” ie, truly dangerous.
And don’t rely on your doctor to remember all the various drug interactions. As an article in American Family Physician, the journal of the American Academy of Family Physicians, noted: “It is no longer practical for physicians to rely on memory alone to avoid potential drug interactions.”
To that end, here are the most common, clinically significant drug interactions. If you are taking such drugs, or your doctor prescribes one that interacts with another you’re taking, ask about alternatives. Just remember: Never stop taking a medication without first checking with your doctor, and always tell your doctor everything you’re taking, including over-the-counter medications, vitamins, minerals, and herbal and nutritional supplements.
|If you’re taking . . .||Then try to avoid . . . *||Because they may . . .|
|Coumadin (warfarin)||These antibiotics: ciprofloxacin, metronidazole and trimethoprim, sulfamethoxazole, azithromycin, clarithromycin, erythromycin, telithromycin||Make warfarin less effective|
|Acetaminophen (Tylenol). More than 2 grams a day for a week|
|Aspirin||Increase your risk of bleeding|
|Non-steroidal anti-inflammatories (Motrin, Aleve)|
|Fluoroquinolone antibiotics such as Avelox (moxifloxacin), Cipro (ciprofloxacin), or Levaquin (levofloxacin)||Calcium, magnesium/aluminium (Maalox, Mylanta, etc), aluminum (Alu-Cap, AlternaGel, etc), iron, magnesium||Reduce absorption of the antibiotic 60 to 70 percent|
|Tegretol (carbamazepine), Dilantin (phenobarbital and phenytoin)||The antibiotics azithromycin, clarithromycin, erythromycin, and telithromycin, Tagamet (cimetidine), and Diflucan (fluconazole)||Inhibit an enzyme called cytochrome P450, which helps your liver metabolize these drugs, resulting in a dangerous build up of the medications|
|Rifadin (rifampin)||Reduce absorption of the drug resulting in breakthrough seizures|
|Lithium||Diuretics and non-steroidal anti-inflammatories (Motrin, Aleve)||Affect how the kidney works, which could increase blood levels of lithium|
|Oral contraceptives||Rifampin (and, possibly, other antibiotics); Rezulin (roglitazone)||Lead to breakthrough bleeding and increased risk of pregnancy|
|Propulsid (cisapride)||The antibiotics azithromycin, clarithromycin, erythromycin, and telithromycin, Tagamet (cimetidine), and Diflucan (fluconazole)||Result in potentially fatal effects|
|Viagra (sildenafil)||Any form of nitrates||Lead to extremely low blood pressure|
|Erythromycin, Tagamet (cimetidine), Nizoral (ketoconazole), and (Sporanox) itraconazole||Increase the amount of drug in the bloodstream|
|Lipitor (atorvastatin), Baycol (cerivastatin), Lescol (fluvastatin), Mevacor (lovastatin), Pravachol (pravastatin), Zocor (simvastatin)||Erythromycin, Sporanox (itraconazole) niacin, Lopid (gemfibrozil)||Lead to kidney failure and muscle damage, among other serious effects|
*Other drugs may also cause interactions; these are the most common