What are the side effects of antihistamines?

What are the side effects of antihistamines?
  • Drowsiness.
  • Dry mouth, dry eyes.
  • Blurred or double vision.
  • Dizziness and headache.
  • Low blood pressure.
  • Mucous thickening in the airways.
  • Rapid heart rate.
  • Difficulty urinating and constipation.
Takedown request   |   View complete answer on my.clevelandclinic.org


What are the side effects of taking antihistamines daily?

Are there side effects from taking antihistamines daily?
  • Drowsiness.
  • Constipation.
  • Urinary retention.
  • Dry mouth.
  • Increased appetite.
  • Weight gain.
  • Increased heart rate.
Takedown request   |   View complete answer on singlecare.com


Is it OK to take antihistamines every day?

Depending on your symptoms, you can take antihistamines: Every day, to help keep daily symptoms under control. Only when you have symptoms. Before being exposed to things that often cause your allergy symptoms, such as a pet or certain plants.
Takedown request   |   View complete answer on medlineplus.gov


What are three possible side effects when taking an antihistamine?

Drowsiness, dizziness, constipation, stomach upset, blurred vision, or dry mouth/nose/throat may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Takedown request   |   View complete answer on webmd.com


What drugs should not be taken with antihistamines?

Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication.
Takedown request   |   View complete answer on webmd.com


Side effects due to prolonged use of antihistamines - Dr. Sriram Nathan



Is there a natural antihistamine?

A common herb in natural medicine, stinging nettle, may also be a natural antihistamine. In a 2000 study, 58 percent of participants found their symptoms relieved with the use of freeze-dried nettles, and 69 participants rated it better than the placebo. Stinging nettle can be found online and at health food stores.
Takedown request   |   View complete answer on healthline.com


How long do antihistamines stay in your system?

For the average healthy adult, elimination half-life ranges from 6.7 to 11.7 hours. So between 6 to 12 hours after taking Benadryl, half the drug will be eliminated from the body. Within two days, the drug will be completely gone from the body.
Takedown request   |   View complete answer on riveroakstreatment.com


What is the safest antihistamine?

Loratadine, cetrizine, and fexofenadine all have excellent safety records. Their cardiovascular safety has been demonstrated in drug-interaction studies, elevated-dose studies, and clinical trials. These three antihistamines have also been shown safe in special populations, including pediatric and elderly patients.
Takedown request   |   View complete answer on pubmed.ncbi.nlm.nih.gov


Do antihistamines raise blood pressure?

"In general, antihistamines are safe in patients with high blood pressure and other forms of heart disease," explains Richard Krasuski, MD, director of adult congenital heart disease services at the Cleveland Clinic in Ohio, but an antihistamine may elevate blood pressure or increase heart rate, according to the U.S. ...
Takedown request   |   View complete answer on everydayhealth.com


Do antihistamines make you gain weight?

Studies suggest that the prolonged use of antihistamines like Allegra are linked to a roughly 10% increase in body weight, body mass index, and waist circumference. Children who use antihistamines also appear to be at risk.
Takedown request   |   View complete answer on verywellhealth.com


Does taking antihistamines weaken immune system?

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.
Takedown request   |   View complete answer on pubmed.ncbi.nlm.nih.gov


How do you wean off antihistamines?

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.
Takedown request   |   View complete answer on nswtag.org.au


How long does antihistamine withdrawal last?

The antihistamine withdrawal timeline depends on the specific drug. The withdrawal signs usually begin between 48 and 96 hours after the last dose. They usually peak between days 3 and 5 and can last between 1 and 7 days.
Takedown request   |   View complete answer on wellnessretreatrecovery.com


What happens if you take too many antihistamines?

In overdose symptoms can include dizziness, tachycardia, headache drowsiness or agitation. While the current generation of lesser sedating antihistamines do not affect the QT interval at normal doses (unlike the previous generation of medicines), there are concerns there may be some effect in overdose.
Takedown request   |   View complete answer on rch.org.au


Does your body get used to antihistamines?

The causes for the diminished effect of antihistamine drugs are far less clear. The bulk of evidence will tell you that drug tolerance does not occur no matter how long or aggressively the drugs are used. If anything, their prolonged use will reduce a person's tolerance to their side effects, particularly drowsiness.
Takedown request   |   View complete answer on verywellhealth.com


Which antihistamine is best for elderly?

So what can older adults safely take for allergy relief? Wozniak: Newer antihistamines such as Claritin® (loratadine) and Allegra® (fexofenadine) tend to be safer and better tolerated.
Takedown request   |   View complete answer on perks.optum.com


Do antihistamines affect your heart?

Antihistamines, which are commonly used to treat symptoms such as a runny nose or sneezing, are generally safe for patients with abnormal heart conditions. However, the FDA has warned that antihistamines taken in conjunction with some high blood pressure medications may cause a spike in blood pressure.
Takedown request   |   View complete answer on heartrhythmdoc.com


Can antihistamines cause heart palpitations?

Many medicines, including diet pills, antihistamines, decongestants, and some herbal products, can cause heart palpitations. Nearly everyone has palpitations from time to time.
Takedown request   |   View complete answer on myhealth.alberta.ca


Can you take antihistamines with blood pressure tablets?

While most antihistamines are generally safe to take with your blood pressure medication, we want you to keep in mind the following drug interactions if you are taking medicines for your blood pressure: Fexofenadine (Allegra) and Carvedilol (Coreg): This may increase the side effects of fexofenadine.
Takedown request   |   View complete answer on aspireallergy.com


Which foods are natural antihistamines?

People with allergies may find relief by using natural plant extracts and foods that act as antihistamines. Antihistamines are substances that block histamine activity in the body.
...
1. Vitamin C
  • bell peppers.
  • broccoli.
  • cantaloupe melon.
  • cauliflower.
  • citrus fruits.
  • kiwifruit.
  • strawberries.
  • tomatoes and tomato juice.
Takedown request   |   View complete answer on medicalnewstoday.com


Can antihistamines cause stroke?

Dr Eric Matheson and colleagues from the Medical University of South Carolina said in the Journal of the American Board of Family Medicine that their findings 'indicate that hay fever is an independent risk factor for first stroke. Patients with hay fever who use antihistamines may be at particularly great risk.
Takedown request   |   View complete answer on theguardian.com


Why is Benadryl not suitable for over 65s?

Because age-related changes occur in the cholinergic system, there is concern that strong anticholinergic effects may lead to a decline in cognitive function or even precipitate delirium in older adults. Diphenhydramine can have significant cognitive and performance-related adverse effects even in younger patients.
Takedown request   |   View complete answer on uspharmacist.com


Can antihistamines make you anxious?

Antihistamines

Antihistamines are known to cause extreme drowsiness; however, in certain people, they can cause insomnia, excitability, anxiety, restlessness, and a rapid heart rate.
Takedown request   |   View complete answer on ercare24.com


Can I drink alcohol while taking antihistamines?

Allergy medications can be used to treat seasonal and year-round allergies, but combining them with alcohol can be risky. Diphenhydramine (Benadryl) causes drowsiness, so it's especially dangerous to combine with alcohol.
Takedown request   |   View complete answer on goodrx.com


How much antihistamine can I take in 24 hours?

Adults—5 to 10 milligrams (mg) once a day. Children 6 years of age and older—5 to 10 mg once a day. Children 4 to 6 years of age—2.5 mg once a day, up to a maximum of 5 mg once a day or 2.5 mg twice a day.
Takedown request   |   View complete answer on mayoclinic.org