Most people are familiar with at least some of the things that can impair memory, including alcohol and drug abuse, heavy cigarette smoking, head injuries, stroke, sleep deprivation, severe stress, vitamin B12 deficiency, and illnesses such as Alzheimer’s disease and depression.

But what many people don’t realize is that a number of commonly prescribed drugs also can interfere with memory. Here are seven of the top types of memory-robbing medications.

7. Antihistamines (first generation)

Why they are prescribed: These medications are used to relieve or prevent allergy symptoms or symptoms of the common cold. Some antihistamines are also used to prevent motion sickness, nausea, vomiting and dizziness, and to treat anxiety or insomnia.

Examples: Brompheniramine (Dimetane), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist), diphenhydramine (Benadryl) and hydroxyzine (Vistaril).

How they can affect memory: These medications (prescription and over-the-counter) inhibit the action of acetylcholine, a chemical messenger that mediates a wide range of functions in the body. In the brain, they inhibit activity in the memory and learning centers.

Caution! These Drugs Can Cause Memory Loss