Do you sometimes think you are getting forgetful? Antihistamines (first-generation) may be contributing to your memory loss.
First-generation antihistamines treat allergies by blocking the action of histamine, a substance produced by your body in response to an allergen, causing your allergic symptoms. They are available over the counter and may cause drowsiness.
First-generation antihistamines generally cause more side effects because they can penetrate the brain tissue. Second-generation drugs have fewer side effects because they usually cannot enter the central nervous system.
Examples of first-generation antihistamines include: Brompheniramine (Dimetane), carbinoxamine (Clistin), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist), diphenhydramine (Benadryl) and hydroxyzine (Vistaril).
How do first-generation drugs 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.
What are the alternatives?
Newer-generation antihistamines such as loratadine (Claritin and Alavert)) and cetirizine (Zyrtec) do not present the same risks to memory and cognition.
Exampes of other second-generation antihistamines include: Astelin(azelastine), Clarinex (desloratadine), Allegra (fexofenadine), Xyzal(levocetirizine) and Patanase (olopatadine).
Many other commonly prescribed drugs also can cause memory loss. Antihistamines rank in the top ten. The other top nine include:
1. Antianxiety drugs (Benzodiazepines)
2. Cholesterol-lowering drugs (Statins)
3. Antiseizure drugs
4. Antidepressant drugs (Tricyclic antidepressants)
5. Narcotic painkillers
6. Parkinson's drugs (Dopamine agonists)
7. Hypertension drugs (Beta-blockers)
8. Sleeping aids (Nonbenzodiazepine sedative-hypnotics)
9. Incontinence drugs (Anticholinergics)