The number of drugs hitting the market every day is more than enough to make any single person's head spin. It's hard enough for a pharmaceutical company to test for drug interactions, let alone for doctors or even patients to keep up with all the risks. There are plenty of checks and balances in place, and several drugs have been pulled after in-market observation. So how can the average person keep up?
This article will briefly discuss the most common types of dangerous drug interactions, and is in no way an exhaustive discussion. Always check with your doctor and pharmacist if you have concerns about potential interactions or strange side effects, even if they don't appear on any side effect lists for your medications. Also, for the latest health tips, prescription drug news and more follow our blog.
What is an interaction?
Not all drug interactions are dangerous. Some interactions merely diminish the effectiveness of one or more of the medications you're taking. Sometimes they make the effectiveness better, improving the way your body processes and reacts to the medication. Not all interactions involve two or more drugs either (i.e., drug-food, drug-condition), nor does the symptom of interaction necessarily reflect the side effects of the medications you're taking. According to Mosby's Medical Dictionary:
(A drug-drug) interaction may be the result of a chemical-physical incompatibility of the two drugs or a change in the rate of absorption or the quantity absorbed in the body, the binding ability of either drug, or an alteration in the ability of receptor sites and cell membranes to bind either drug. Most adverse drug-drug interactions are either pharmacodynamic or pharmacokinetic in nature.
For any interactions not directly due to drug combinations, it's the molecular incompatibility, or the effect of the chemical makeup of the interacting agent on the body that alters a medication's results. For instance, in patients taking antiretroviral medications, the drug(s) have an effect on the liver or kidneys, altering the amount of chemicals or other substances normally filtered by those organs; if a drug improved liver function, there could be a positive interaction (better liver function) or a negative interaction (worsened ability to absorb the antiretroviral, worsened liver function).
Unfortunately, some drug interactions can be deadly.
Dangers to health
As mentioned, some interactions can be quite dangerous, severe or even deadly. This is particularly true for children and the elderly. According to the AMDA, the medication combinations that are most dangerous for the elderly are:
- Warfarin and NSAIDs
- Warfarin and Sulfa drugs
- Warfarin and Macrolides
- Warfarin and Quinolones
- Warfarin and Phenytoin
- Ace inhibitors and Potassium supplements
- Ace inhibitors and Spironolactone
- Digoxin and Amiodarone
- Digoxin and Verapamil
- Theophylline and Quinolones
A general list of medications to be especially careful with is:
- SSRIs (antidepressants focused on serotonin reuptake) - Consult your doctor regarding pain medications, antihistamines, St. John's Wart.
- HTCZ (blood pressure medication) - Consult your doctor regarding heart rhythm medication, decongestants, foods like licorice.
- Statins (cholesterol lowering medications) - Consult your doctor regarding yeast infection or other fungal medications, Vitamin B, citrus (especially grapefruit).
When in doubt, review the documentation that comes with your medication, be it on the bottle/container or an extra pamphlet. Any questions should be directed to your doctor, your pharmacist, or the phone number listed in the medication's documentation.
For more information
Head to the FDA's webpage, "Drug Interactions: What you should know." It has plenty of useful information, including where to look for information on your medication or over-the-counter drugs and a more complete list of potential drug-drug, drug-food and drug-condition interactions. A slightly more specific list can be found at UPMC's eNews Center.
