When antihistamines block histamine, our appetite can increase. This, plus side effects like drowsiness, could lead to weight gain. Your risk of gaining weight from antihistamines may depend on many factors. But a healthy diet, physical activity, and other lifestyle factors can help you manage your risk.
Benadryl (diphenhydramine) has also been linked to weight gain in some patients. However, newer antihistamines such as Claritin (loratadine) are associated with lesser weight gain as compared to the antihistamines mentioned above.
It has long been known that the administration of antihistamines can cause weight gain. In fact, one antihistamine, cyproheptadine, has been used for this purpose. There are many postulations as to why this occurs.
Weight gain from medications is not uncommon, and in fact it is an often overlooked cause of weight gain or difficulty losing weight. Antihistamines are one such type of medication that has been associated with weight gain.
“The most common side effects you tend to see are fatigue, headaches, and dry mouth,” says Shih. If you're someone for whom the benefits of regular antihistamine use far outweighs the occasional minor side effect, longterm use is safe for most adults and children, he adds.
Side effects of antihistamines
sleepiness (drowsiness) and reduced co-ordination, reaction speed and judgement – do not drive or use machinery after taking these antihistamines. dry mouth. blurred vision. difficulty peeing.
Popping a Benadryl® or Claritin® for the occasional allergy attack won't put on the pounds. But longer-term use of some antihistamines may, according to a study published in the journal Obesity. Histamine, the chemical that makes your nose runny at peak pollen season, also plays a role in reducing hunger.
While newer-generation antihistamines like Allegra and Zyrtec are less likely to cause drowsiness than older drugs like Benadryl, they have been linked to an increased risk of weight gain in some users.
Common drugs that cause unwanted pounds include corticosteroids, antidepressants, diabetes medications such as insulin or those containing sulfonylureas, some heartburn drugs, hormone therapy/contraceptives, and anti-seizure drugs such as Depakote®.
H1 receptor antihistamines such as cetirizine, fexofenadine, and desloratadine are among the most commonly prescribed medications for the treatment of allergies and have been shown to stimulate appetite and weight gain as side effects of treatment (6).
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.
Antihistamines have side effects that include altered mental state, urinary retention and dry mouth. While these side effects are generally mild and well tolerated in young patients without other medical problems, they can pose a risk, especially for the elderly.
Antihistamines can ease your symptoms, but they work best when you take them before you feel a reaction. They can build up in your blood to protect against allergens and block the release of histamines. Ask your doctor if you should start taking allergy medicine a couple of weeks before you usually have symptoms.
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.
Claritin and Zyrtec are effective and safe for most people with minor allergies. However, as with all medications, there may be some side effects. Loratadine—present in Claritin—may not be safe for people with severe liver conditions.
For many people with allergies, symptoms are the worst around 4 a.m. to 6 a.m. Taking an antihistamine at bedtime may help you or your child feel better in the morning during allergy season.
While some over-the-counter antihistamines can cause drowsiness, routinely using them to treat insomnia isn't recommended.
How long should I take cetirizine for? It depends on why you're taking cetirizine. You may only need to take it for a short time or as a one-off dose. For example, if you have a reaction to an insect bite, you may only need to take cetirizine for a day or two.
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.
"Itching can occur within one-two days of stopping Zyrtec or Xyzal after long term daily use (months to years). It usually lasts a few days and then resolves. The intensity of the itching can be from mild to severe. Occasionally, a brief burst of oral steroids may be needed to help the patient get off the drug.