Health Update

by Tyrone M. Reyes, M.D.

A doctor friend of mine recently had a consult with an older woman who was taking 26 medications. She was under the care of a family physician, a rheumatologist, a cardiologist, and a psychiatrist and none of them were aware of what the others were prescribing. To make matters worse, a recent visit to an emergency room for nausea added an antibiotic to the woman’s list of drugs. She didn’t need the antibiotic. Her nausea was being caused by digoxin, a drug prescribed by her cardiologist to control her heart rate but which can also bring gastrointestinal distress. Once the woman’s blood digoxin level was brought under control (she was taken off for a short while), her nausea subsided.

The antibiotic wasn’t the only drug the woman didn’t need. After reviewing all of his patient’s 26 medications, my doctor friend, using the Beers Criteria for Potentially Inappropriate Medication Use in Older Adults, was able to cut the number of drugs she was taking almost in half. Her particular case is extreme, but it’s illustrative of a broader phenomenon that needs more attention: People older than 65 may make up only about 15 percent of the population, but they consume 30 percent of all prescription drugs. In fact, many older adults take an average of three to five medications, and that doesn’t include over-the-counter products such as pain relievers, vitamin supplements, and herbs.

Taking several medications put older people “at greater risk for redundant drug effects, drug-drug interactions, and medication errors,” says Jerry Gurwitz, MD, chief of Geriatrics at the University of Massachusetts Medical School. Seeing more than one doctor only ups the chances that something could go wrong. Michael Langan, MD, a gerontologist who specializes in pharmacology at Massachusetts General Hospital, points out that “the medical community — from physician to pharmacy — is not a closed loop system. Oftentimes, even within the same hospital, there is no communication.” In other words, there is no central coordinating place to make sure the whole drug “menu” is right for a person. The lack of communication often leads to what is known as a prescribing cascade — giving medicine to treat symptoms that are not the result of a health condition but instead result from taking another drug. That’s what happened to my doctor friend’s patient. Her nausea led someone to assume she had a bacterial infection that required an antibiotic, when in fact the nausea was entirely due to another drug.

Drugs And The Aged

Along with having several doctors who may rarely — or never — consult with one another, older people are at risk because they’re more susceptible to adverse drug effects for physiologic reasons. For instance, with age, there’s an increase in body fat, and since many drugs are fat soluble, there’s a chance that they will remain stored in the body longer — increasing the chances for overdosing. Also, age harbingers a decline in liver and kidney function, which means drugs are not cleared from the body as effectively as they are in younger people.

A drug’s receptor site — where it’s supposed to act on a cellular level — might be different in older people, too. For example, the neurotransmitters of an older person’s central nervous system might not function exactly like those of a younger person, which could explain why the elderly are more likely to experience sleepiness when taking an antidepressant like Zoloft or Prozac. Since most drugs are tested in younger people, it is often not well known how older people will respond to them.

Drugs Older Adults Should Avoid

A report in the December 12, 2001 issue of the Journal of the American Medical Association (JAMA) suggests that millions of people aged 65 and older have taken medications that may cause problems for people their age. The study’s findings highlight the need for older persons to be informed about the medications they are taking — especially when adding a new prescription to their daily mix.

With help from an expert panel, the researchers composed a list of 33 medications considered to be “potentially inappropriate” for use by seniors due to serious side effects or the availability of safer and more effective alternatives. The experts divided the 33 drugs into the following three categories:

• Always inappropriate. The study determined that in 1996, nearly three percent (about 840,000) of older Americans living outside of nursing homes might have used one or more drugs that the panel agreed were never appropriate for use by this age group (See listing below.) A prime example is meperidine (Demerol), a pain reliever that may cause seizures in older people. There are so many better choices available for the treatment of pain. The panel believes there is no reason to choose Demerol.

• Rarely appropriate. Of the eight drugs on this list prescribed to an estimated nine percent of older adults in the US, only two are available in the Philippines. These are diazepam (Valium, Anxionil, and others) and chlorzoxazone (Parafon Forte). Those available in the US include chlordiazepoxide (Librium), propoxyphene (Darvon), carisoprodol (Sodol), cyclobenzaprine (Flexeril), metaxalone (Skelaxin), and methocarbamol (Delaxin). A good example of drugs in this list is propoxyphene, a commonly taken painkiller in the US. It is no more effective than aspirin or acetaminophen (Tylenol), has a sedative effect, and can be addictive.

• Appropriate for certain uses. The panel felt that these drugs can be prescribed in particular circumstances — for example, when the person doesn’t respond to a better drug — but should still be avoided, if possible. Prescribed in 13 percent of older adults in 1996, this list includes the following medications available in the Philippines: indomethacin (Indocid, Infree), dipyridamole (Persantin, Prexin, Aggrenox), ticlopidine (Ticlid), methyldopa (Aldomet and others), reserpine (Rauverid, Ser-Ap-Es), disopyramide (Norpace), oxybutynin (Driptane), chlorpheneramine (antihistaminic/decongestant mixed with other medications and sold under various brand names, such as Nafarin A, Sinutab Extra Strength, and others), diphenhydramine (Benadryl, Caladryl, and others), hydroxyzine (Iterax, Marax), and promethazine (Phenergan). In addition, it also includes the following drugs sold in the US but not available locally: amitriptylene (Elavil), doxepin (Adapin), and cyproheptadin (Periactin).

Inappropriate Drugs For Older Adults

Here are the medications considered inappropriate for older adults to take:

• Barbiturates (e.g. Luminal). Potential side effects: Clumsiness, unsteadiness, drowsiness, dizziness, memory impairment; potentially addictive.

• Flurazepam (e.g. Dalmane). Potential side effects: Memory impairment, confusion, dizziness, unsteadiness; daytime drowsiness; addictive.

• Meprobamate (e.g. Equanil — not available in RP): Potential side effects: Clumsiness, unsteadiness, drowsiness, muscle twitches.

• Chlorpropamide (e.g. Diabinese): Potential side effects: Low blood sugar, seizures, dizziness, loss of consciousness.

• Meperidine (e.g. Demerol). Potential side effects: Slow or labored breathing, confusion, drowsiness, seizures; potentially addictive.

• Pentazocine (e.g. Talwin — not available in RP). Potential side effects: Drowsiness, dizziness, blurred vision, confusion.

• Trimethobenzamide (e.g. Tigan — not available in RP). Potential side effects: Drowsiness, dizziness, blurred vision, confusion, seizures.

• Dicyclomine (e.g. Formulex — not available in RP). Potential side effects: Memory impairment, confusion, drowsiness, nervousness, urinary retention, seizures.

• Hyoscyamine (not available in RP). Potential side effects: Memory impairment, confusion, drowsiness, agitation, blurred vision, urinary retention.

• Propantheline (e.g. Pro-banthine — not available in RP). Potential side effects: Nervousness, drowsiness, confusion, blurred vision, sweating, rapid heartbeat (tachycardia).

• Belladonna alkaloids with phenobarbital (e.g. Donnatal — not available in RP). Potential side effects: Dry mouth, blurred vision, urinary retention, confusion, memory impairment, drowsiness.

How To Protect Yourself

If you currently take one of the potentially inappropriate medications mentioned in this article, don’t suddenly stop taking it. However, you should ask your doctor to explain why you are receiving it and ask if there is an alternative. The nomenclature of drugs can be complicated, and many drug names sound alike. Also, people oftentimes think of their medications very generally, in terms such as “my blue pill” or “water pill” or “heart pill.”

So, bring all your prescriptions and dietary supplements to your doctors every time you visit. This will allow your physicians to identify potential problems if your prescriptions and dosages change. The message is this: Be wary. Sometimes, too many drugs can create problems even while solving them, especially in older people.

Source: Philippine Star