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 a common cause for hospital admission. 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 explosive.

This is especially true for patients with Alzheimer's disease or other memory conditions, because so many medications can impair memory. A recent study presented before the American Academy of Neurology shows that anticholinergics, which are commonly prescribed for managing bowel and bladder conditions, directly conflict with the drugs commonly used to slow the progression of Alzheimer's disease.

Scientists at the Uniformed Services University of the Health Sciences in Bethesda, Md., studied the use of anticholinergics to treat urinary incontinence in 870 Catholic nuns and clergy members with an average age of 75. The results showed that cognitive function declined 50 percent faster in subjects who took anticholinergic drugs compared to those who did not. For the healthy individual, the impact of memory loss is minimal, but for patients with cognitive impairment such as Alzheimer's disease, this "speeding up" of memory decline is very serious.

Ultimately, this study highlights how the science behind specific treatments and medications can have multiple unintended effects. In this case, the chemical messenger acetylcholine plays opposing roles in two different illnesses.

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. The drugs Aricept, Razadyne and Exelon all inhibit this enzyme, called anticholinesterase; hence acetylcholine levels increase and memory improves.

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, explaining 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.

In the case of the bowel, the most commonly prescribed drugs are the anticholinergics Bentyl and Donnatol. They cause the bowel to relax, relieving abdominal pain, and together with diet they can help control the very uncomfortable symptoms of irritable bowel syndrome.

In the case of the bladder, the most common medication is Detrol. This drug causes 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 another medical condition benefiting from the use of anticholinergic drugs despite the negative impact on memory. Luckily, in the case of urinary incontinence, there are a series of newer, more expensive medications that do not cross into the brain. These include Vesicare, Enablex and Sanctura. It is said that these medications do not impair memory.

When it comes to managing medications, it is vitally important that you understand the function of every drug you take. Older adults should always avoid medications that can impair memory or contribute to memory loss. In the fight against negative drug interactions, a pharmacist is your best asset.

Find a good pharmacist, develop a relationship with him, 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 of the drugs that you are taking.

Dr. David Lipschitz is the author of the book "Breaking the Rules of Aging." To find out more about Dr. David Lipschitz and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com. More information is available at www.drdavidhealth.com.

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