Prescription medications offer amazing benefits for controlling the symptoms of illness, or even leading to a cure. But they can also put you at risk for more serious illness, or even death.

According to experts, a staggering 1.5 million Americans die each year from medication mistakes, and many of them are senior citizens.

Dr. Patricia Salber, a leading internist and emergency care physician from San Francisco who runs the website TheDoctorWeighsIn.com, tells Newsmax that the numbers may be growing because so many baby boomers are now seniors, and are taking prescription drugs.

And many elderly people cannot tolerate certain medications — even medications the patient has taken before.

“Basically, any drug that needs to be cleared from the kidneys can be problematic for the elderly, who have reduced renal function,” says Salber. “Also, many drugs have anticholinergic effects, which can cause cognitive changes including delirium. They can also cause urinary retention and constipation. I always recommend a trial of nondrug intervention before resorting to prescription medication.”

Here are six most risky classes of drugs for seniors:

1. Diabetes drugs with a long half-life, in particular Diabinese (chlorpropamide), should be avoided by seniors because of the risk of prolonged and serious hypoglycemia (low blood sugar). Short-acting agents such as Glucotrol (glipizide) are good alternatives.

2. Anticholinergic antihistamines such as diphenhydramine (Benadryl and others) should also be avoided if possible because they can cause confusion, dry mouth, constipation, urinary retention, cognitive impairment, and delirium. Clearance of these drugs from the body is slower in elderly patients. Alternatives include Allegra (fexofenadine) and Claritin (loratadine).

3. Muscle relaxers like Flexeril, Robaxin, and others can also cause anticholinergic effects. Alternatives are to treat a muscle condition with physical therapy, ergonomics, and application of heat or cold.

4. Oral mineral oil for constipation can be aspirated and cause inflammation of the lungs. Alternatives are increased fiber in the diet along with adequate hydration.

5. Benzodiazepines for anxiety (like Valium) should be used with caution by seniors because they can lead to or worsen cognitive impairment. They can also cause delirium and an unsteady gait, which increases the risk of falls with serious consequences, including hip fractures. Alternative therapies for anxiety include nondrug interventions such as behavioral therapy or relaxation techniques like yoga.

6. Triamterene and other potassium-sparing diuretics, such as amiloride and spironolactone, should be used with extreme caution by the elderly, who may have reduced renal function. This could cause dangerous elevations in potassium levels, which can lead to serious or even fatal cardiac arrhythmias.

“It’s important to remember that these are very useful drugs, it’s just that they have to be used with caution by the elderly,” says Salber. “Remember that old age is no longer defined by a number. There are plenty of 60- to 70-year-olds who are vigorous and have good kidney function. And there are also many 50- to 60-year-olds who, as we say in medicine, appear older than their stated age.

“Recommendations need to be personalized based on the doctor’s evaluation of the overall physiological state of the individual. This is the age of personalized medicine, so we need to use all this information to help guide our decision in a more targeted way.”

It’s also important to read labels carefully and follow recommendations for taking the medication. If you are taking any prescription medications, make sure your doctor knows, so you don’t end up taking multiple drugs that have similar side effects.