Antihistamines can be helpful when it comes to stomach acid problems, but they may also increase your risk for the Clostridium difficile infection. Here's what you need to know.
While we already knew that antibiotics – which kill bacteria by definition – can dramatically alter the gut microbiome, the team found that antihistamines, hormonal contraceptives and anti-inflammatory drugs also appear to have an effect.
Yep, antihistamines can have an effect on your bowel habits as well! Again, this is down to the medications' effects on acetylcholine signaling.
These common side effects include sedation, impaired motor function, dizziness, dry mouth and throat, blurred vision, urinary retention and constipation. Antihistamines can worsen urinary retention and narrow angle glaucoma. The antihistamines rarely cause liver injury.
In the GI tract, histamine is believed to impact at least 3 major functions: modulation of GI motility, enhancement of gastric acid production, and alteration of mucosal ion secretion.
The bacterial histamine then activates the gut immune system through histamine-4 receptor, which draws immune mast cells into the intestines. These activated mast cells produce even more histamine and other pain-signalling mediators, triggering inflammation and pain.
High levels of histamine can also trigger digestive symptoms like bloating [7], and diarrhea [8], heart rate changes or palpitations [9], low blood pressure [10], and headaches [11].
Newer antihistamines like Allegra and Claritin are generally safe for daily use. But allergy medications with decongestants, such as Claritin-D or Benadryl-D, could make your allergies worse with long-term use.
Long term use of some antihistamines may increase your risk of dementia. Diphenhydramine (Benadryl®) blocks the effects of a neurotransmitter called acetylcholine. This neurotransmitter is vital for memory and learning.
David Shih, executive vice-president of strategy and former chief medical officer at CityMD, explained to The Cut that second-generation antihistamines, like the commonly available over-the-counter drug loratadine, are generally safe for long-term use.
Patients with irritable bowel syndrome (IBS) have increased pain perception, but the underlying cause of this hypersensitivity is unknown.
You can also experience side effects from taking a regular antihistamine—like Zyrtec, Claritin, or Benadryl—including dry mouth, confusion, flushing, visual impairment, and fever. What's more—getting off antihistamines can cause allergic reactions as well.
Conclusion: Our findings indicate that sedating first-generation H1R antihistamines and H2R blockers might impair innate immune responses to bacteria and that these drugs should be used with caution in patients with severe bacterial infections.
No interactions were found between Benadryl Cold and Probiotic Formula.
Allergists recommend long-acting, non-sedating antihistamines — ones that won't make you sleepy — for everyday use. Though you may know them by their brand names, the generic versions tackle the same problems: Cetirizine (Zyrtec®, Aller-Tec®, Wall-Zyr®). Fexofenadine (Allegra®, Aller-ease®, Aller-Fex®, Wal-Fex®).
Is it safe to take Zyrtec every day? Yep. "When taken in the recommended doses, antihistamines can be taken daily. This is especially true with Zyrtec, since it doesn't show decreasing effectiveness if used daily," says Sima Patel, MD, an allergist at New York Allergy & Sinus Centers.
People who take antihistamines regularly may build up a tolerance to the drug, which means they need to take higher and higher doses to get the same effect. This can lead to addiction. Antihistamines are often addictive because they work by blocking histamine receptors.
Cetirizine is unlikely to do you any harm if you take it for a long time. However it's best to take cetirizine only for as long as you need to. If you take it regularly over a long period there's a very small chance of severe itching if you stop treatment suddenly.
You should not use Zyrtec-D if you have narrow-angle glaucoma, severe high blood pressure (hypertension), severe coronary artery disease, if you are unable to urinate, or if you are allergic to hydroxyzine (Atarax, Vistaril). Do not use this medicine if you have taken an MAO inhibitor in the past 14 days.
In general, wean gradually by 25-50% of the daily dose every 1-4 weeks. If reason for deprescribing is serious adverse effects, wean faster or cease immediately. Provide advice to patient/carer on self-monitoring and what to do if symptoms re-occur.
Magnesium is a mineral that relieves the constriction of the airways in the lungs. It's been found that magnesium deficiency can cause an increase in histamine levels in the blood after being exposed to allergens.
Among the putative histamine-secreting bacteria in GTDB, five genera including Bacteroides, Clostridium, Bifidobacterium, Fusobacterium, and Lactobacillus are common in the human gut microbiota [29,30,31,32].
Histamine is a signaling molecule, sending messages between cells. It tells stomach cells to make stomach acid. And it helps our brain stay awake.
Coffee contains histamines in low amounts, but for people who are sensitive to them, it contains plenty to get a reaction out of them. While the natural histamine content in coffee is low, some coffee processes can increase histamine levels.