What are the side effects of long-term use of antihistamines?

What are the side effects of long-term use of antihistamines?

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.

What are older antihistamines?

The first-generation or “older” antihistamines (e.g., chlorpheniramine, diphenhydramine) are effective in reducing sneezing, itching, and rhinorrhea. They have untoward side effects, however, that are particularly notable in the elderly patient.

What are the side effects of first-generation antihistamines?

Some of the common side effects of first-generation antihistamines include:

• 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.

What should you not mix with antihistamines?

Some products that may interact with this drug are: antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray), blood pressure medications (especially guanethidine, methyldopa, beta blockers such as atenolol, or calcium channel blockers such as nifedipine).

What should you not take with antihistamines?

Examples of medicines that could cause problems if taken with antihistamines include some types of:

• antidepressants.
• stomach ulcer or indigestion medicines.
• cough and cold remedies that also contain an antihistamine.

What happens when you stop taking antihistamines?

The main withdrawal symptom is called pruritus— itching and burning sensations of the skin ranging from moderate to severe. Other antihistamine withdrawal symptoms include interruptions in sleep patterns.

Is it OK to take antihistamines to sleep?

While some over-the-counter antihistamines can cause drowsiness, routinely using them to treat insomnia isn’t recommended. Antihistamines, mainly used to treat symptoms of hay fever or other allergies, can induce drowsiness by working against a chemical produced by the central nervous system (histamine).

How long does it take for antihistamines to get out of your system?

Official Answer. The elimination half-life of Zyrtec is between 8 to 9 hours. It takes approximately 5.5 x elimination half-life for a medicine to be cleared from your system. For Zyrtec this is 5.5 x 9 hours which is about 2 days.

Can you become dependent on antihistamines?

Although widely used and generally considered safe, cases of antihistamine abuse and dependence, especially of DPH, have been described in the medical literature (Thomas et al. 2009). Those misusing antihistamines have listed calming effects (Cox et al.

How long before allergy testing should I stop taking antihistamines?

For best results from your skin test, you should avoid most antihistamines for at least 7 days prior to skin testing. Many guidelines only recommend 3-4 days of avoidance prior to skin testing, but a significant number of patients will still have some reduced skin test response for up to 7 days.

Should I stop taking antihistamines before allergy blood test?

Make sure you do not take antihistamines before the test, as they can interfere with the results. If your GP has recommended a skin prick test for you or your child, you can watch a video about how a skin prick test works and how to prepare for the test on The Health and Care Video Library.

What medications should I stop before allergy testing?

Medications to STOP 3-4 days prior to Testing

• Actifed, Dimetapp (Brompheniramine)
• Atarax, Vistaril (Hydroxyzine)
• Benadryl (Diphenhydramine)
• Chlortrimetron (Chlorpheniramine)
• Dexchlorpheniamine (Polaramine)
• Phenergan (Promenthazine)
• Vitamin C.
• All allergy eye drops OTC and RX (as tolerated)

Does antihistamine affect blood test?

Unlike the skin prick test, the blood test is not affected by antihistamines and can be performed for people with extensive rashes that prevent using skin tests.

Which is more accurate skin test or blood test for allergies?

Generally speaking, skin tests are more sensitive than blood tests, meaning they are more likely to detect allergies that a blood test may miss. Skin tests also require less wait time, as results are typically delivered in 15-20 minutes, rather than the one to two week wait time of blood tests.