doctor in a lab coat with a handful of pills

The news this week about aggressive control of hypertension (see this news article) will doubtless lead to many more prescriptions for blood pressure medicine. As it is, Americans are taking more medicine than ever (JAMA, Nov. 3, 2015). The number of people taking five or more drugs simultaneously has nearly doubled from 8% to 15% in a decade. Many older people are taking far more than that.

When people take that many medicines together, the risk for a dangerous, or even a deadly drug interaction, goes up dramatically. One study revealed that prescribers performed terribly on a test of drug incompatibility (Drug Safety, 2008). The health care professionals classified less than half of the fourteen drug pairs they were tested on correctly. This was a take home test, so they could have looked up the right answers had they been so motivated.

The authors concluded: “This study suggests that prescribers’ knowledge of potential clinically significant DDIs [drug-drug interactions] is generally poor.”

Overriding Deadly Drug Interaction Warnings:

Computerized systems are supposed to alert doctors when a dangerous or a deadly combination has been prescribed to a patient. But another study found that doctors frequently override and ignore the drug interaction alert they may get on their smart phone or computer. The research was carried out at six Veterans Affairs (VA) medical centers (American Journal of Managed Care, Oct., 2007). Over a one-year period there were 291,880 drug-drug interaction alert overrides. Nearly three fourths of the overrides were considered “critical drug-drug interactions.”

We received this message from Nanci in Illinois:

Q. I see a cardiologist, a rheumatologist, have a primary doctor, and none of them ever gives me drug interaction information!! I asked one cardiologist about the side effects and interactions of a new beta blocker he was prescribing. His answer: “I don’t know.”

I changed doctors, but still have to ask. My current heart doc looks up interactions in his desk reference. If I don’t ask, he just writes the script with no instructions. The pharmacist is better and always asks me if I have any questions.

It would be nice if doctors were more knowledgeable about the side effects of the meds they pass out like candy.

I have a friend who is 85 years old and who takes a beta blocker, an ACE inhibitor, a calcium channel blocker (CCB) plus a diuretic at fairly high doses. His blood pressure is quite low. He said he passed out briefly in his garage at one time, but never questions his meds.

Doctors are overworked but they should do a better job of informing their patients of potential drug interactions and side-effects.

A. We agree with you Nanci. In fact it is critical that patients be warned by both physicians and pharmacists about both side effects and drug incompatibilities. Sadly, this does not happen nearly enough. Both pharmacists and physicians override interaction alerts with great regularity.

Is a Deadly Drug Interaction Warning Really Deadly?

Many doctors may override or ignore computer-generated drug interaction warnings because they don’t really think they are all that worrisome. That is a little like playing Russian Roulette with a patient’s life.

A study of 24,849 alerts at primary care practices affiliated with two Harvard teaching hospitals produced shocking results (PLoS One, Dec. 26, 2013):

“We found that, despite extensively modifying our CDS [clinical decision support] system to improve user acceptance and show only the most important alerts, providers continued to override these alerts that are likely to cause serious patient injuries. More needs to be done to effectively [provide] feedback to providers with high inappropriate override rates and improve prescribing safety in the primary care setting.”

The People’s Pharmacy translation of that stuffy medical language is: “we tried to make the deadly drug interaction alerts better and easier to use but doctors kept ignoring them anyway.”

What Are the Consequences of Ignoring a Deadly Drug Interaction Warning?

Canadian researchers have been concerned about a deadly drug interaction linked to a class of blood pressure medicines called RAS (Renin-Angiotensin System) inhibitors. These include the ACE inhibitors Nanci mentioned in her question as well as ARBs (angiotensin receptor blockers). Popular drugs in the RASi class include lisinopril (Prinivil, Zestril) and ramipril (Altace) as well as losartan (Cozaar) and valsartan (Diovan). You can find a more complete list of RAS inhibitors at this link.

When the Canadians combed through their patient database over a 17-year time period they discovered that people who had received either an ACE inhibitor or an ARB blood pressure drug together with co-trimoxazole were more likely to have died within two weeks of receiving the combination compared to people who had received a different kind of antibiotic (penicillin type). Described in BMJ (Oct. 30, 2014).

The investigators concluded that the combination of the co-trimoxazole antibiotic and the blood pressure medicine “increased risk of sudden death in older patients.” They also noted that such deaths were likely to be blamed on underlying heart disease rather than a drug interaction. To read more about this landmark research go to this link.

The Canadian researchers have also demonstrated that a popular diuretic (spironolactone) can also trigger life-threatening complications when it is combined with the same antibiotic (CMAJ, Mar. 3, 2015). Their interpretation:

“The antibiotic trimethoprim-sulfamethoxazole was associated with an increased risk of sudden death among older patients taking spironolactone.”

How Can Patients Protect Themselves from a Deadly Drug Interaction?

In our book, Top Screwups Doctors Make and How to Avoid them, you will find a whole chapter on this crucial subject. You will also discover our list of Top 11 Tips for Preventing Dangerous Drug Interactions. If you know someone who is taking a handful of pills every day, you may want to give him or her a copy of this book. The examples we have provided barely scratch the surface of the deadly drug interaction disaster that is played out every day in this country and around the world. Here is a link to Top Screwups.

Please share your own experience with drug interactions below in the comment section and vote on this article at the top of the page.

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  1. Nadine

    My husband had a massive coronary arrest back in 2008. He survived but his rehab was long and slow. He now is doing good. Back when he had his coronary arrest, it was discovered that Greg was diabetic. He also had 100% blockage in the Prox. LAD and further down 80% blockage around the OM. The stents that were placed and saved my husbands life were/are Antiplatelet Medication Stents, which means Greg has to take several medications.

    Since 2008, Greg has taken Plavix, Lipitor, Lisinopril, Lopressor, and Metformin. About 2 years ago the drug, Januvia, was added to the rest. Now, I have been reading this article, and some of the other articles and some of the reviews. I am very worried that some of the cognitive problems going on with my husband are the results of these drug interactions. Could there be interactions between all these drugs?

    • Terry Graedon

      This question is worth asking both the doctor and the pharmacist. We don’t see any red flags here, but his health care providers should be pro-active.

  2. Mary

    I am allergic to a number of meds but had been on blood pressure meds for several years. During that time I developed a cough that would not go away no matter what I did. I looked up the side effects of the drug and cough was among them. My doctor changed to another med and I had worse reaction–BP bottomed out, heart rate went crazy and kidneys were affected. I stopped it immediately. However, it took almost a month before I got back to normal. I insisted the doctor let me drop the meds except the fluid pill and he did. I am 80 yr. old and I have been able to keep the pressure at a reasonable level. In my case, I take as few meds as I possibly can. That would be my advice for everyone; at least ask about meds and side effects and be pro-active in your treatment as well as be informed.

  3. liz

    I, too, am concerned about so many medications and no one professional REALLY studying what is going on. I started taking notice when both feet, ankles and legs suddenly became swollen. Which doc to call? Nephrologist said do not worry – elevate legs. Cardiologist said do not stop Diltiazem because it is helping your a-fib so well – tolerate swelling. Long story short I finally received permission to stop Diltiazem and swelling is gone after two months with massage and exercise. Feet and ankles still very tender and painful when touched.

    I personally do not think it does any good to change doctors when you have a problem. That is unless you have a really good reason! It is difficult to get their attention but the long term goal is for the docs and patients to work together to get a good care plan. Patients have to do their homework, too.

    You can get an appointment with a doctor and say you want to develop a personal care plan based on what you say about your body and what the tests reveal. Medicare has covered these doctors visits so far. I am trying to do this very systematically, with one problem at a time; I think this way of working with the docs is going to be satisfying.

    So far, I am taking only two pills now: thyroid and blood thinner. I was taking ten. My blood pressure has stabilized at normal. My a-fib episodes are almost non existent. The challenge is that I am in charge of the plan and ultimately in charge of my treatment. It is difficult for the doctor to listen to this way of thinking by a patient. But if we would all do this, maybe our health care system will improve and become world class! What do other folks think about this way of taking hold of our health care?

  4. David

    As a Senior, I see a number of doctors for multiple health problems. Like many people, I’ve experienced the various side effects and interactions, sometimes very debilitating, from many different meds.

    Recently, I discovered through the internet, that some meds diminish or even elevate the efficacy/efficiency of others! ie: a drug taken for BP may increase risk, severity and/or duration of (hypoglycemia) blood sugar in people who take (certain?) antidiabetic meds.

    At least one of the steroid meds may reduce the effects of a different med taken for lowering BP. Thus the latter may be unable to treat, or be effective, as intended.

    Not all doctors know/think or have time to research this when prescribing for their specialty. I feel that such (interactions/effects) information would be helpful if the manufacturer would include it in the printed information sheets that accompany each drug, as a backup.

  5. Angie
    St. Louis, MO

    RXLIST.COM has a box on the left side of their homepage that checks medicine interactions. I have caught 2 possibly dangerous interactions by using it. It gives the warnings in yellow, orange, red and black. Anytime I get a new medicine, I check it there before taking.

  6. Gordon
    Eugene, OR

    I had heart bypass and valve replacement surgeries in March, 2015. I developed A-Fib a couple of days after the surgery and was immediately given amiodarone via IV and oral tablets after the “loading dose.” Amiodarone is FDA approved ONLY as a last resort drug for ventricular fibrillation, not atrial fibrillation,though it is routinely used for a-fib. In addition to amiodarone-induced major thyroid damage for which I am still being treated, I was placed in grave danger when a doctor prescribed Cipro for an infection I developed later. Thankfully, my pharmacist caught the warning about an amiodarone/Cipro combination being potentially fatal and I was switched to amoxicillin.

  7. Edwinna
    San Antonio, Tx

    Everyone reading this post has a computer/smartphone/tablet. We must take responsibility for going online to a reputable website and doing our own research any time we are given a new prescription! If you are a caregiver for someone without online access, take the responsibility of doing it for them.

  8. wendy

    Please send further conversations in this thread.

  9. ariel

    when i ask a dr this they say ask the pharmacist. I recently got a script filled at a new drugstore and i thought to ask if she had checked the med against the list of meds that i could not take. She had not. I thought this was supposed to be routine.

  10. Cara

    I almost died from taking Actos. My doctor at the time didn’t listen to me. Neither did a hospital ER room doctor and two other doctors. They don’t want people to question them and don’t care about side effects or drug interactions. Ask a pharmacist about these things. They are better informed than the doctors.

  11. Carol

    Where do I find a physician that treats patients naturally and doesn’t continually push pills on you.

  12. V

    I had a valve replacement and was given Amiodarone last resort medicine for a brief afib episode. The Surgeon and hospital did not tell me anything about this drug. I should of never been on it because I have a thyroid condition. After a month on this drug I woke up one morning not being able to see out of my right eye. The drug caused optic nerve damage. All of this could of been prevented if the doctor would of read the side effects and told me to get an eye exam after two weeks of being on the drug also to get a thyroid test. My Thyroid went haywire for almost a year

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