How to avoid medication mishaps

Today’s medications offer longer and healthier lives to millions of people affected by heart disease, diabetes, arthritis, cancer, and many other diseases.  Many ailments that killed people in the past are now curable, and many short-term illnesses are more nuisances than serious problems because they can be managed well with medications.  But these benefits come with a caveat:  Used inappropriately or incorrectly, prescription drugs may not help a patient very much and may even cause harm.

It’s also clear from daily news reports that even though drugs are tested extensively, they can cause unanticipated problems.  For example, postmenopausal estrogen, after decades of immense popularity, tumbled from favor when a large, long-term study showed prolonged hormone therapy raised women’s risk of breast cancer, heart disease, and stroke.

Some unexpected consequences of medications may be more bizarre than dangerous.  For instance, a relatively small number of people taking the insomnia drug zolpidem (Silnox in PH; Ambien in the US) experience strange nocturnal behavior.  Some users arise during the night and, while unaware of doing so, walk or eat uncontrollably.  Incredibly, some even drive their cars.

Most side effects won’t kill you, but they can range from unpleasant to potentially harmful.  We have no accurate statistics available on how many serious drug complications occur in the Philippines.  But in the US, adverse drug reactions result in more than 700,000 visits to hospital emergency rooms each year, according to the Centers for Disease Control and Prevention.  Whenever you start a new medication, you should be aware that side effects might occur, and you should know what to do if you think you’re having one or more of them.  This is especially true for older adults, who are at greater risk of experiencing drug side effects.

WHAT ARE SIDE EFFECTS?

A drug side effect is simply an unwanted effect of a medication. Side effects are often predictable, based on how the drug functions in the body.  An example is low blood sugar (hypoglycemia) due to insulin and certain other diabetes drugs.  Almost everyone who takes too much of some of these medications will develop hypoglycemia.

All drugs have potential side effects.  Indeed, at some point, you’ve probably squinted down the list of possible side effects on the package insert of your medications.  They probably include a panoply of unpleasantries, such as blurred vision, drowsiness, dizziness, dry mouth, heart palpitations, erectile dysfunction, memory impairment or nervousness.  Fortunately, many of these side effects occur in only small numbers of people. And if you know how to interpret these lists of side effects, they may be a useful resource instead of a source of anxiety.

You should suspect a side effect any time you have symptoms not normally associated with your illness or medical condition. Side effects may appear shortly after you start a new medication, after you switch from one brand or formulation of a drug to another, after your doctor raises the dosage or when a new drug is added to your regimen and it interacts with one of your other medications. Though unlikely, you may also suddenly experience a side effect or unusual symptoms from a drug you previously had been taking with no ill effects.

Types of side effects

Adverse drug reactions may be surprising, but they often happen for a reason.  Finding out the cause can determine how to solve the problem.

• Dose-related side effects. One common type of side effect is the result of too much of a good thing.  For instance, drug for high blood pressure may cause dizziness or light-headedness if they lower blood pressure too much.  This can happen if the prescribed dosage is too high, if your body is unusually sensitive to the drug or if the blood-pressure drug interacts with another medication that amplifies its effects.

• Gastrointestinal side effects. Problems in the gastrointestinal tract, such as nausea, loss of appetite, constipation or diarrhea, are common side effects.  One reason is that drugs taken orally may irritate the sensitive lining of the stomach or intestines.

• Allergic reactions.  Immune system responses triggered by a medication can have widespread and occasionally even dangerous effects.  Symptoms of an allergic reaction to drugs vary but commonly include skin rashes, hives, and itching.  Less common but potentially deadly is a severe white-body allergic reaction called anaphylaxis.  Telltale signs of anaphylaxis include difficulty breathing, rapid pulse and stridor (a whistling or groaning sound while trying to inhale). Anaphylaxis demands emergency medical attention.

• Drug-drug interactions. Drugs sometimes interact in the body, either amplifying or weakening the effect of one or the other, which is why you need to keep your doctor fully informed about every medication or substance you take, including over-the-counter remedies and dietary supplements.  Important drug-drug interactions are commonly identified before most drugs reach the market.

• Drug-food interactions. Some foods and drinks don’t mix well with certain medications.  For example, grapefruit contains a substance that affects the activity of an enzyme that processes certain medications in the intestines and liver.  Eating grapefruit or drinking grapefruit juice could lead to a dangerous increase in the level of one of these drugs in your blood.

• Drug-alcohol interactions. Alcohol mixes badly with many medications.  Among the more dangerous alcohol-drug interactions are those that cause excessive drowsiness or difficulty breathing.  It’s wise to avoid alcohol altogether while taking a new medication unless you specifically ask your doctor whether it’s safe.

• Systemic side effects.  While some drugs act precisely to target the cause of a disorder, most don’t.  Most drugs act throughout the body, or systemically. These drugs affect tissues or systems not involved in the problem being treated. One example is nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin or ibuprofen.  NSAIDs reduce pain but can cause an upset stomach and, less commonly, gastrointestinal bleeding.

Drugs that act systemically are more likely to cause side effects than drugs that act locally.  One way around this problem is to deliver the drug closer to the organ or tissues that need the help.  Generally, locally delivered drugs include topical preparations applied to the skin, eyes, ears, hair or mucous membranes; injections of drugs into the skin or joints; and inhalers that deliver drugs to the lungs. All these local drugs have some systemic absorption, but it’s usually small and inconsequential.

IF YOU’RE AN OLDER ADULT

For people, aged 65 and older, drug safety takes on special importance. Older adults are more likely to experience side effects from prescription drugs than young people are, partly because of physiological changes in the body that commonly accompany aging.

Also, it’s common for older people to be on multiple medications — a practice referred to as polypharmacy.  People, aged 65 and older, usually comprise only about 13 percent of the population, but they consume 30 percent of all prescription drugs. The average older adults take between three and five prescription drugs, and many older adults take over-the-counter medications and supplements as well.

For older people, it’s especially important to take only the minimum effective dose of all drugs.  Younger people have a greater margin of safety for larger doses of prescription drugs because their livers and kidneys are in prime condition to remove medications from the blood.  In older adults, however, reduced liver and kidney function can impair the ability to remove unused or excess drugs from the blood.  The medication “left over” from one day to the next can build up in the blood. Eventually, the drug blood concentration may become high enough to cause side effects.

Older bodies have also more fat relative to bone and muscle. So when an older person takes a drug that dissolves in fat, the medication may become trapped in the body fat, making less of it available to treat the illness.  Older people’s stomachs may also produce less digestive acid.  This means that when an older person takes a drug that dissolves in acid, the drug takes longer to break down and be absorbed than it would be in a younger person.

Sidestepping drug side effects

The more you know about your medications, the less likely you’ll suffer preventable side effects.  Here are basic strategies for avoiding side effects and adverse drug reactions:

•  When you’re prescribed a new drug, ask your doctor to describe the most likely side effects and to distinguish between the most common side effects and the rare but more dangerous ones.

• Ask for specific instructions on the best way to take the drug — with or without food, for example, or whether the drug could interact harmfully with any over-the-counter medications, dietary supplements or alcoholic beverages.

•  Know which drugs you can’t stop taking all at once.  Some drugs must be tapered off gradually to prevent withdrawal or “rebound” effects.

• Always keep follow-up appointments.  If you’re supposed to return to the doctor regularly for physical exams or blood tests to check your response to the drug, make sure you go.

If you suspect you’re having a bad reaction to a drug, contact your doctor.  Don’t suddenly stop taking your medications if you think you are having a side effect. Always check with your doctor before changing your drug regimen in any way.  The more you know about the drug your doctor prescribes for you, the more likely you will avoid a medication mishap.