David Lee, PharmD, PhD
David Lee, PharmD, PhD, assistant professor in the College of Pharmacy at Oregon State University in Portland. Dr. Lee is also a coauthor of a recent paper on therapeutic competition that was published in the journal PLOS ONE.
Most people who have a chronic health problem such as osteoarthritis, high blood pressure or diabetes are accustomed to taking medication to help control their symptoms.
But if you have more than one chronic condition—and take medication for each of them—you could be setting yourself up for other problems.
The risk that often goes undetected: Taking medication prescribed for one disease may actually worsen another health problem. This situation, known as “therapeutic competition,” has received surprisingly little attention from the medical profession.
Therapeutic competition can occur at any time in a person’s life. But the risk increases with age—the older we get, the more likely we are to have chronic medical conditions and use more medications. Because our bodies metabolize medication less efficiently as we age, we’re also more likely to develop side effects that can worsen other health problems.
Modern medicine has not done very much to help the situation. For one thing, polypharmacy—the use of multiple medications—has become more common than ever before.
For people with more than one chronic medical condition, frequent conflicts occur if you have…
If you also have chronic obstructive pulmonary disease (COPD), drugs that you take to ease your breathing, such as the beta-adrenergic agonist albuterol (Proventil) or a corticosteroid, may raise your blood pressure.
If you are also being treated for depression, an antidepressant such as venlafaxine (Effexor) or duloxetine (Cymbalta) could push your blood pressure higher. COX-2 inhibitors such as celecoxib (Celebrex), commonly used for osteoarthritis, also may increase blood pressure.
Corticosteroids taken for COPD can raise blood sugar levels, worsening diabetes. If you have an enlarged prostate and take an alpha-blocker such as tamsulosin (Flomax) or a beta-blocker such as atenolol (Tenormin) for high blood pressure, the drug can mask symptoms of low blood sugar, such as shakiness.
If you also have high blood pressure or angina and take a nonselective beta-blocker such as propranolol (Inderal), the drug could worsen lung symptoms.
COPD drugs, including albuterol…tricyclic antidepressants such as imipramine (Tofranil), taken for depression…and COX-2 inhibitors for osteoarthritis also can make heart disease worse.
Osteoporosis drugs, including bisphosphonates such as alendronate (Fosamax)…and Alzheimer’s drugs, including cholinesterase inhibitors such as donepezil (Aricept), may worsen atrial fibrillation.
Corticosteroids used to treat COPD often lead to significant bone loss. Glitazones taken for diabetes and proton pump inhibitors such as omeprazole (Prilosec), commonly prescribed for gastroesophageal reflux disease (GERD), can accelerate bone loss.
Warfarin (Coumadin) or clopidogrel (Plavix), often prescribed for atrial fibrillation or heart disease, as well as nonsteroidal anti-inflammatory drugs (NSAIDs), can cause bleeding that worsens GERD and ulcers. Bisphosphonates taken for osteoporosis may aggravate esophageal damage that commonly occurs with GERD and ulcers.
If you have more than one chronic condition and take two or more medications to treat them, it is crucial that you watch for signs of therapeutic competition, such as new symptoms that are unexplained or begin soon after a new medication is started. Any new health condition actually may be an adverse effect of medication.
Important steps to avoid therapeutic competition…
The less medication you’re on, the less likely one of your drugs will adversely affect another condition. Ask your doctor whether it’s advisable to reduce the overall number of prescriptions you take. A drug you have been taking for years may no longer be necessary. You may also be able to make lifestyle changes—such as getting more exercise—that will allow you to cut back on blood pressure or diabetes medication.
If it seems that a drug is worsening another condition, ask your doctor about less harmful alternatives. Some medications are more selective—that is, their effects on the body are more focused on the target illness, making unintended consequences for other conditions less of a danger.
Example: Nonselective beta-blockers, such as propranolol, often worsen COPD symptoms, but medications with more selective action, such as metoprolol (Lopressor), are usually just as effective for the heart problem they’re prescribed for without adversely affecting your lungs.
If you suffer from multiple ailments, you need to tell all your doctors about the medications you take. Also, talk to your pharmacist each time you pick up a new prescription to make sure your drugs aren’t working against each other.
To ensure that no drug-related problems develop: Once a year, have a pharmacist (ask one at your drugstore) review all your medications. This service includes a discussion of side effects, interactions and alternatives. For many people, Medicare Part D and some private health plans will pay for this service. If not, it usually costs less than $100.