The numbers are simply staggering: Every year 1.5 million people are sickened or severely injured by medication mistakes, and 100,000 die. And yet all of those deaths are preventable. What's the answer? We have to protect ourselves. Here are the ten medication mistakes experts say are most likely to kill or cause serious harm.
Confusing two medications with similar names
It can happen anywhere in the transmission chain: Maybe the doctor's handwriting is illegible, or the name goes into the pharmacy computer incorrectly, or the swap occurs when the wrong drug is pulled from the shelves. "Most pharmacies shelve drugs in alphabetical order, so you have drugs with similar names right next to each other, which makes it even more likely for someone to grab the wrong one," says Michael Negrete, CEO of the nonprofit Pharmacy Foundation of California.
According to the national Medication Error Reporting Program, confusion caused by similar drug names accounts for up to 25 percent of all reported errors. Examples of commonly confused pairings include Adderall (a stimulant used for ADHD) versus Inderal (a beta-blocker used for high blood pressure), and Paxil (an antidepressant) versus the rhyming Taxol (a cancer drug) and the similar-sounding Plavix (an anticlotting medication). The Institute for Safe Medication Practices's list of these oft-confused pairs goes on for pages.
How to avoid it: When you get a new prescription, ask your doctor to write down what it's for as well as the name and dosage. If the prescription reads depression but is meant for stomach acid, that should be a red flag for the pharmacist. When you're picking up a prescription at the pharmacy, check the label to make sure the name of the drug (brand or generic), dosage, and directions for use are the same as those on the prescription. (If you don't have the prescription yourself because the doctor sent it in directly, ask the pharmacist to compare the label with what the doctor sent.)
Taking two or more drugs that magnify each other's potential side effects
Any drug you take has potential side effects. But the problems can really add up whenever you take two or more medications at the same time, because there are so many ways they can interact with each other, says Anne Meneghetti, M.D., director of Clinical Communication for Epocrates, a medication management system for doctors. "Drugs can interfere with each other, and that's what you're most likely to hear about. But they can also magnify each other, or one drug can magnify a side effect caused by another drug," says Meneghetti.
Two of the most common -- and most dangerous -- of these magnification interactions involve blood pressure and dizziness. If you're taking one medication that has a potential side effect of raising blood pressure, and you then begin taking a second medication with the same possible effect, your blood pressure could spike dangerously from the combination of the two. One medication that lists "dizziness" is worrisome enough, but two with that side effect could lead to falls, fractures, and worse.
Be particularly careful if you've been prescribed the blood-thinner Coumadin (warfarin), "the king of drug interactions," according to Pharmacy Foundation of California's Michael Negrete. "You need just the right amount of Coumadin in your system for it to work properly; too much or too little and you could have serious heart problems such as arrhythmias or a stroke. But so many other drugs interfere with its action that you have to be really careful."
How to avoid it: Ask your doctor or a pharmacist about potential side effects when you get a new prescription, and make sure the pharmacy gives you written printouts about the medication to review later. Keep all such handouts in a file, so that when you get a new prescription, you can compare the info provided with the handouts from your older prescriptions. If you see the same side effect listed for more than one medication, ask your doctor or pharmacist whether it's cause for concern.
Overdosing by combining more than one medication with similar properties
Think of this one as the Heath Ledger syndrome, says Michael Negrete of Pharmacy Foundation of California. It's all too easy to end up with several medications that all have similar actions, although they were prescribed to treat different conditions. "You might have one medication prescribed to treat pain, another prescribed for anxiety, and another that's given as a sleeping pill -- but they're all sedatives, and the combined effect is toxic," explains Negrete.
The risk for this kind of overdose is highest with drugs that function by depressing the central nervous system. These include narcotic painkillers such as codeine; benzodiazepines such as Ativan, Halcion, Xanax, and Valium; barbiturate tranquilizers such as Seconal; some of the newer drugs such as BuSpar, for anxiety; and the popular sleeping pill Ambien.
But oversedation can also happen with seemingly innocent over-the-counter drugs like antihistamines (diphenhydramine, commonly known as Benadryl, is one of the worst offenders), cough and cold medicines, and OTC sleeping pills. This type of drug mixing is responsible for many medication-induced deaths, especially among younger adults.
How to avoid it: Pay attention to the warnings on the packaging of over-the-counter medications, and the risks listed in the documentation for prescriptions. Key words are sleepy, drowsy, dizzy, sedation, and their equivalents. If more than one of your prescriptions or OTC drugs warns against taking it while driving, or warns that it can make you drowsy, beware. This means the drug has a sedative effect on the central nervous system and shouldn't be combined with other drugs (including alcohol) that have the same effect.
Getting the dosage wrong
Drugs are prescribed in a variety of units of measure, units that are usually notated using abbreviations or symbols -- offering a host of opportunities for disaster. All it takes is a misplaced decimal point and 1.0 mg becomes 10 mg, a tenfold dosing error that could cause a fatal overdose.
Some of the most extreme dosage mistakes occur when someone mistakes a dose in milligrams with one in micrograms, resulting in a dose 1,000 times higher. This mostly happens in the hospital with IV drugs, but it's been known to happen with outpatient meds as well. Insulin, the primary treatment for diabetes, causes some of the worst medication errors because it's measured in units, abbreviated with a U, which can look like a zero or a 4 or any number of other things when scribbled.
Another common problem, says pharmacist Bona Benjamin, director of Medication-Use Quality Improvement at the American Society of Health-System Pharmacists, is getting the frequency wrong -- so, say, a drug that is supposed to be given once a day is given four times a day.
How to avoid it: Make sure your doctor's writing is clear on the original prescription; if you can't read the dosage indicated, chances are the nurse and pharmacist will have difficulty as well. When you pick up the prescription from the pharmacy, ask the pharmacist to check the dosage to make sure it's within the range that's typical for that medication. In the hospital, when a nurse is about to administer a new medication, ask what it is and request that he or she check your chart to make sure it's the right one for you and that the dosage is indicated clearly. Don't be afraid to speak up if you think you're about to get the wrong medicine or the wrong dose.
Mixing alcohol with medications
There are plenty of drugs that come with that cute bright orange warning sticker attached, telling you not to drink when taking them. However, the sticker can fall off, or not get attached in the first place, or you might just really need that cocktail and figure it'll be OK "just this once." But alcohol, combined with a long list of painkillers, sedatives, and other medications, becomes a deadly poison in these situations. In fact, many experts now say you shouldn't drink when on any medication without first checking with your doctor.
Alcohol can also have a dangerous interaction with OTC drugs such as diphenhydramine (Benadryl) and cough and cold medicines -- and if the cough or cold medicines themselves contain alcohol, you can end up with alcohol poisoning. Alcohol can also compete with certain medications for absorption, leading to dangerous interactions. Mix alcohol and certain antidepressants, for example, and you have the potential for a dangerous rise in blood pressure, while alcohol and certain sedatives such as Ativan or Valium can depress the heart rate enough to put you in a coma.
How to avoid it: When you get a new prescription, ask your doctor or a pharmacist if the medication is safe to take while drinking alcohol. If you're a heavy drinker and you know it's likely you'll drink while taking the medication, tell your doctor. She may need to prescribe something else instead. Also, read the handouts that come with your prescriptions to see if alcohol is mentioned as a risk. And read the labels of all OTC medications carefully, both to see if alcohol is mentioned as a risk and also to see if alcohol is an ingredient in the medication itself.
Double-dosing by taking a brand-name drug and the generic version at the same time
With insurance companies mandating the use of generic drugs whenever they're available, it's all too common for patients to get confused and end up with bottles of a brand-name drug and a generic version at the same time without realizing it. "For example, a common diuretic is furosemide. The brand name is Lasix. A patient might have a bottle of furosemide and a bottle of Lasix and not know they're the same thing," says internist Bruce Mann, M.D. "In essence, the patient is taking twice the dose." Since generic drugs don't list the equivalent brand name on the label, you might not spot this unless your brand-name version lists the generic name in the fine print.
How to avoid it: When your doctor prescribes a new medication, make sure you have a chance to go over all the details you might need to know later. Have the doctor write down the name of the drug (brand and generic, if available), what it's for, its dosage, and how often and when to take it. Try to remember both names for future reference. Also, look up the generic names for each of your brand-name prescriptions and vice versa; then line up all of your medicine bottles and see if you have any duplications.
Taking prescription drugs and over-the-counter or alternative medications without knowing how they interact
It's easy to think that something you can grab off the shelf at your local grocery or drug store must be safe, but some of the most common OTC drugs can cause serious reactions. A top contender is medicine-chest staple Maalox, meant to calm digestive upset. A new and very popular version, Maalox Total Relief, contains an ingredient called bismuth subsalicylate that can react dangerously with anticlotting drugs, drugs for hypoglycemia, and anti-inflammatories, particularly ibuprofen and other nonsteroidal anti-inflammatories, or NSAIDs.
Another standby to watch out for is aspirin, which thins the blood. If you forget to stop taking aspirin before a surgical procedure, the result can be life-threatening bleeding.
Then there's the herb Saint-John's-wort, which many people take for depression. The fact that Saint-John's-wort can interfere with prescription antidepressants has received a fair amount of attention, but few people know that it also interferes with the liver's processing of blood thinners such as Coumadin (warfarin) and heart medications such as Digoxin.
How to avoid it: When your doctor is writing out a new prescription, this is also the time to mention or remind her about any OTC meds or supplements you take. Never add a medication without discussing how it interacts with what you're already taking.
Foods That Can Have Dangerous Interactions With Your Medications
The most serious culprit in this situation is grapefruit juice, which has unique properties when it comes to inactivating or overactivating medications. Grapefruit juice inhibits a crucial enzyme that normally functions to break down and metabolize many drugs, such as antiseizure drugs and statins used to lower cholesterol. The result? The overloaded liver can't metabolize the medication, resulting in an overdose, with potentially fatal consequences.
Other less serious interactions to be aware of include coffee and iron; the coffee inhibits absorption. Doctors say they frequently see coffee drinkers who take their iron in the morning with breakfast, yet their anemia doesn't go away because the iron isn't absorbed. Grapefruit interactions are serious enough that they're often listed on medication handouts, but many food and drink interactions aren't mentioned.
How to avoid it: When you get a new prescription, ask your doctor or a pharmacist whether you should take it with food, without food, and if there are any particular dietary issues to watch out for.
Failing to adjust medication dosages when a patient loses kidney or liver function
Loss of liver or kidney function impairs your body's ability to rid itself of toxins, or foreign substances, so medications can build up in the body at higher dosages than intended. According to Bona Benjamin of the American Society of Health-System Pharmacists, a common -- and often serious or fatal -- mistake that doctors make is not decreasing medication dosages when patients begin to suffer impaired kidney or liver function. There are many medications that doctors shouldn't prescribe without first ordering liver and kidney function tests, but safety studies show that's often not happening.
How to avoid it: When you bring home a new prescription, read the fine print to see if liver or kidney function is mentioned. If so, ask your doctor if you've had recent liver and kidney function screenings.
Taking a medication that's not safe for your age
As we age, our bodies process medications differently. Also, aging brings with it an increased risk of many problems such as dementia, dizziness and falling, and high blood pressure, so drugs that can cause these side effects are much riskier for people over the age of 65.
Since the early 1990s, a research team led by Mark Beers, M.D., has compiled criteria for medications that should no longer be considered safe for those over 65. This list of Inappropriate Medications for the Elderly, known informally as the "Beers List," is a great resource if you or someone you're caring for is over 65.
How to avoid it: Take the Beers List to your doctor and ask her to check it against all medications prescribed. Sadly, a recent Beers survey found that among those over 65, more than 16 percent had recently filled prescriptions for two or more drugs on the Beers list, suggesting that many doctors are still uninformed about the risks of these drugs. If you discover that you or a family member over 65 is taking medications that are considered risky, you may need to be proactive and ask the doctor to find alternatives.