10 Drugs That May Cause Memory Loss

10. Antihistamines (First-generation)

Why they are prescribed:
These medications are used to relieve or prevent allergy symptoms or those 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), carbinoxamine (Clistin), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist), diphenhydramine (Benadryl) and hydroxyzine (Vistaril).

How they can cause memory loss:
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, which can lead to memory loss.

Alternatives:
Newer-generation antihistamines such as loratadine (Claritin) and cetirizine (Zyrtec) are better tolerated by older patients and do not present the same risks to memory and cognition.