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Doctor insights on: Antihistamine

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Dr. Paul Carter
634 Doctors shared insights

Antihistamine (Overview)

Sedating and non-sedating antihistamines prevent and treat allergic reactions, and are helpful to control itching.


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What do antihistamines do for vertigo?

What do antihistamines do for vertigo?

Vertigo: They may help if it is caused by an allergy but otherwise not much.

Dr. Paul Carter
634 Doctors shared insights

Antihistamine (Overview)

Sedating and non-sedating antihistamines prevent and treat allergic reactions, and are helpful to control itching.


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What exactly does an antihistamine do to the body? I have chronic nasal congestion, will it improve that or worsen it?

What exactly does an antihistamine do to the body? I have chronic nasal congestion, will it improve that or worsen it?

Decrease inflammatio: Antihistamines may decrease the inflammation caused by allergies causing your nasal congestion. It can't make it worse. It should improve it, if allergy is the cause. Try to figure out what the allergic cause is, if it is something like dust, a hepaair filter might help and you might need to rely on antihistamines. The causes are many including mold, dust, pollen, etc.

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What is the highest dosage of antihistamine that one person can take at one time?

Antihistamines: Safety of high dose medications is often unknown. Our experience comes from case reports of persons who intentionally or accidentally consumed unusually excessive quantities. When Claritin (loratadine) was first investigated, safety studies were done at 40 mg (4 times the current recommended dose). We take 10 mg because effectiveness is not significantly different between 10 mg and 40mg.

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If cilia flush mucus from the nose and antihistamines stop cilia function, wouldn't prescribing the antihistamine be counterproductive?

If cilia flush mucus from the nose and antihistamines stop cilia function, wouldn't prescribing the antihistamine be counterproductive?

Good question: Even if antihistamines may have an effect on muco-ciliary clearance from the nose, the drug does not completely eradicate mucus clearance and the benefit of the antihistamine should out-way any effect on ciliary movement. Viral infections have a more profound effect on ciliary motility. I doubt that antihistamines "stop" ciliary function. The drug is only indicated with allergy.

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Should I stay up overnight to keep an eye on my 3yr old after allergic reaction? She had lip swelling and was prescribed antihistamines.

Should I stay up overnight to keep an eye on my 3yr old after allergic reaction? She had lip swelling and was prescribed antihistamines.

Do not have to: Now that it's under control and you do not use the same substance that caused the reaction, it should be ok.

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Can we use antihistamine containing drugs in hypertensive ptn.

Can we use antihistamine containing drugs in hypertensive ptn.

Antihistamine and BP: Antihistamines are fine, but be cautious with those combinations that contain decongestants.

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What is the most effective antihistamine antihistamine with anti emetic properties?

Usually not: Antihistamine has minimal effect on vomiting although Phenergan (promethazine) may provide mild benefits. Zofran will likely be more effective. You need to find out what may be causing your vomiting first.

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Do antihistamines work for skin reactions?

Do antihistamines work for skin reactions?

Possible: Antihistamines work by blocking histamines. Histamine is a chemical that can cause itchiness and hives. So it is possible that antihistamines can help for skin reactions.

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How long until an antihistamine works on post nasal drip?

How long until an antihistamine works on post nasal drip?

THEY WON'T HELP MUCH: Other than drying it up a bit and thickening it, which can cause cough. The key in trying to eliminate postnasal drip is to cut the inflammatory or environmental response that it is caused by.

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When I take antihistamine pills for hives, I get more itchy right after taking the pills before they kick in a few hrs later. Am I allergic to pills?

When I take antihistamine pills for hives, I get more itchy right after taking the pills before they kick in a few hrs later. Am I allergic to pills?

Be specific: You fail to indicate WHICH antihistamine. All antihistamines need time to see effect. Some are more effective than others. What type of hives, what specific trigger? Allergy to antihistamine is possible but not likely. Vague itching soon after a dose is not a good reason to suspect allergy.

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Why is it dangerous to take antihistamines with addarall?

Why is it dangerous to take antihistamines with addarall?

Interaction: The potential sedating effect of an antihistamine will counteract the stimulant efect of Adderall (dextroamphetamine and racemic amphetamine). Speak to your doctor about an alternative combination.

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Is constant use of antihistamine toxic to body or not?

Not really: Antihistamines are generally safe for long term use.

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How can I safely test to see if an antihistamine produces drowsiness? I know even the new generation has this side effect.

How can I safely test to see if an antihistamine produces drowsiness? I know even the new generation has this side effect.

Wait until a day: When you don't have to go to school (weekend) and try it. It's the only way to know. Take the smallest dose available and see if it works.

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What are the side effects of antihistamines and what can we do about each?

3rd generation AH: Older antihistamines (AH) like Benadryl, (diphenhydramine) Atarax, Periactin caused drowsiness and dry mouth in at least 30% of the people. Weight gain in another potential side effect. Newer antihistamines like Zyrtec, Xyzal causes drowsiness in about 10% of the people 3rd generation AH like Allegra and Claritin are not expected to cause drowsiness in 95% of the people.

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What will happen if you take 80 sleepasil tablets + 5 antihistamines and half a bottle of gin?

Wanting to die: You will sleep and wake up with a very bad hangover and feel no different than you do right now. Nothing will be solved. Perhaps it is time to get to a drug and alcohol treatment center and just follow their suggestions and get into a fellowship of other hurting humans who will love you till you can love yourself again.

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