When it comes to managing medications, it is paramount that you understand every drug you use, whether prescribed, over the counter, or “natural.” Negative drug interactions are the most common causes of hospital admission. A good example is taking an antidepressant together with alcohol, which neutralizes the benefits of the medication.

Another good example is the use of a beta blocker. This lowers the blood pressure, slows and prevents an irregular heart rate, and reduces the risk of a heart attack. Many patients requiring treatment for heart disease often have coexisting lung disease, including chronic obstructive lung disease and asthma. Here, treatment uses drugs having the exact opposite effect of a beta blocker. When used together, they neutralize each other.

With age, taking multiple medications is more and more common. Understanding your own medications can be difficult enough, but for the caregiver of a dependent loved one, the whole process can be particularly difficult.

This is especially true for patients with Alzheimer’s disease or other memory conditions, because so many medications can impair memory. A study just published in the Journal of the American Medical Association showed that dementia is far more likely in patients taking anticholinergic drugs, including the antihistamine Benadryl (diphenhydramine), Elavil (amitriptyline), antispasmodics to treat abdominal pain and medications used to treat overactive bladder. Earlier research has shown that these drugs often accelerate the rate of memory loss in patients with Alzheimer’s disease and other causes of dementia. Anticholinergic medications work by lowering acetylcholine levels in many parts of the body, including the brain.

Acetylcholine helps send neurological signals from one nerve cell to another. It mediates many important functions in the body, including retention of memory. One of the cardinal features of Alzheimer’s disease is an impaired ability to retain short-term memory caused by a depletion of acetylcholine levels in the brain. Today, the drugs used to treat Alzheimer’s disease attempt to raise concentrations of acetylcholine in brain cells by inhibiting the enzyme responsible for its breakdown. By increasing acetylcholine concentrations in the brain, we hope to improve memory and slow the progression of the disease.

Acetylcholine also plays a role in stimulating the bladder to contract (leading to urination) and regulates normal and integrated movement of the gastrointestinal tract (leading to the orderly movement of food). Acetylcholine is responsible for releasing saliva at the beginning of a meal, which explains why your mouth waters when you think of food.

Hyperactivity and dysfunctional contraction of the bowel and the bladder, such as “irritable bowel syndrome” or incontinence, are treated with anticholinergics — drugs that suppress acetylcholine levels. This causes the bowel to relax, relieving abdominal pain, and together with diet can help control the very uncomfortable symptoms of irritable bowel syndrome. In the case of the bladder, anticholinergics cause the bladder to relax, expand more and contract more slowly.

Simply put, for patients with memory loss, treatment will aim to boost acetylcholine levels. For patients with hyperactive bowel or bladder problems, treatment aims to suppress acetylcholine levels. If you have both conditions, the situation is not good.

In some cases, you may be forced to choose one issue over another. For example, it may be more important to treat urinary incontinence or other medical conditions benefiting from the use of anticholinergic drugs despite the negative impact on memory. Luckily, in the case of urinary incontinence there are newer, more expensive medications that do not cross into the brain. These include Vesicare, Enablex and Toviaz.

When it comes to managing medications, it is vitally important that you understand the function of every drug you take. For older adults, you should always avoid medications that can impair memory or contribute to memory loss. In the fight against negative drug interactions, a good pharmacist is your best asset. Find a good pharmacist, develop a relationship with him or her, and stick with the same pharmacy. This way, you and your pharmacist will be a strong team in identifying and avoiding any possible side effects..

Dr. David Lipschitz is the director of the Dr. David Health and Wellness Center in Little Rock. To find out more about Dr. David Lipschitz, visit www.drdavidhealth.com