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Doctor insights on: Third Generation Antihistamine

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Which third generation antihistamine is best for itchy flaky scalp and skin levocetirizine, desloratadine or fexofenadine?

Which third generation antihistamine is best for itchy flaky scalp and skin levocetirizine, desloratadine or fexofenadine?

None of them!: Good morning,
itchy scalp is due to irritation to the nerves of skin of the scalp. There is a nerve signal going from the scalp to the brain telling that there is something not right on the scalp. Correcting the local condition of the scalp such as dryness, scaling, seborrhea, bacterial or fungal overgrowth, and skin flaking condition will relieve the itch. Antihistamines are not useful for this. ...Read more

Dr. Paul Carter
648 Doctors shared insights

Antihistamine (Definition)

Sedating and non-sedating antihistamines prevent and treat allergic reactions, and are ...Read more


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Which antihistamine is safe to take in the third trimester of pregnancy?

Which antihistamine is safe to take in the third trimester of pregnancy?

None: There is no anti-histamine that is 100% safe for use in pregnancy. This class of medications contains variants of amphetamines which can accelerate your heart rate and consequently the baby's. Fetal heart rates above 200 beats per minute can cause fetal cardiac arrest. A runny nose untreated will not put the fetus at risk. ...Read more

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What is the difference between first and second-generation antihistamines?

What is the difference between first and second-generation antihistamines?

Side effects: The second generation antihistamines were developed to try and decrease the side effects of the first generations. Many are "purified" first generation antihistamines so they have the active effects without the side effects of drowsiness, sedation, dry mouth etc. They also tend to have longer half lives, meaning they can be taken once or twice a day not every 4 hours. ...Read more

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Difference between first and second generation antihistamines? Why are 1st generation considered nonsedating?

Difference between first and second generation antihistamines? Why are 1st generation considered nonsedating?

Sedation: 1st generation are sedating because many people, up to 40%, get sleepy when taking them. 2nd generation antihistamines are chemically modified and are less likely to cause sedation. The generics of the less sedating are cetirizine, fexafenadine, and loratidine. They cause sedation in some people, up to 11%, but much less than the older drugs. ...Read more

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Are first generation antihistamines more effective than second generation? I always wonder why some are still on drugstore shelves, like chlorpheniram

Are first generation antihistamines more effective than second generation? I always wonder why some are still on drugstore shelves, like chlorpheniram

Less side effects: There are many medications that remain on shelves for over-the-counter use that probably should be removed. New generation antihistamines are as effective as old ones. Of interest is that some individuals respond favorably to one over the other. The side effect profile and frequency of dosing is what really separates the new from the old antihistamines. In this case, newer is better. ...Read more

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Doctors, what is the difference between first and second generation antihistamines?

CNS: The 1st generation AH gets into the brain area thereby blocking the stimulatory effect on alertness from histamine. The 2nd generations ones do not get into the brain and thus do not usually induce drowsiness.
1st gen- more drying and better for runny nose, the sedating effect also better for itching than 2nd gen. ...Read more

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Where can I find a reliable list of 2nd generation (and newer) oral antihistamines available in the US?

Where can I find a reliable list of 2nd generation (and newer) oral antihistamines available in the US?

No long List: The newer oral nonsedating antihistamines available without prescription in the US are: loratadine (Claritin), fexofenadine (Allegra), cetirizine (Zyrtec) and levocetirizine (Xyzal). Desloratadine (Clarinex) is available by prescription. Some of the insurance medication plans will cover some of the above over-the-counter antihistamines. ...Read more

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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. ...Read more

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Hi im at my wits end can you please help im a long term sufferer of urticaria on massive doses of second generation antihistamines and doxepin and?

Chronic urticaria: Chronic urticaria can be very difficult to manage, and requires a specialist. If you have already seen an allergist but s/he is not very gifted at managing severe hives, you may need a second opinion from another one. There are a number of allergists who do this across the country, but some are more comfortable with hard cases than others. You may need more labs or different medications ...Read more

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What's the difference between a first generation antihistamine like chlorpheniramine and second generation antihistamines like allegra (fexofenadine)?

1st and second: First generation antihistamines are sedating and short acting and have usually other properties such as anticholinergic or drying properties. Second generation antihistamines are long aciting, usually dosed once a day, and are less or non sedating and selective antihistamines with less active properties on other receptors. ...Read more

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Is antihistamines first generation effective drug for common cold and does vitamin c important during common cold?

Is antihistamines first generation effective drug for common cold and does vitamin c important during common cold?

Probably not: Antihistamines are effective for sneezing and runny nose due to allergies, by blocking histamine receptors, . but can over dry nasal passages during colds. Atrovent nasal spray helps runny nose and decongestants (use Short term only) help congestion. Vitamin C may help prevent colds, but not as effective once you have one. Rest, fluids, chicken soup, zinc, humidifier, and netipot help. ...Read more

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What is the reason behind 1st generation antihistamine induce sleep (by which mechanism cause sleepiness in our brain)?

What is the reason behind 1st generation antihistamine induce sleep (by which mechanism cause sleepiness in our brain)?

Anticholinergic: First generation antihistamines block the h1 and h2 histamine receptors but also have some anticholinergic effects by partially blocking other receptors. This can lead to dry mouth, urinary retention, sedation and other side effects. This is usually dose dependent and worsens with high doses. ...Read more

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What is the best OTC antihistamine?

OTC antihistamines: The second generation zyrtec, allergra or Claritin (loratadine) are comparative. None are perfect. Zyrtec is slightly more likely to make you tired ot sleepy. Often one works a little better than another and I adise you to test all three. ...Read more

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Is antihistamine harmful to the body?

No: Antihistamines are a class of medication used since the 1940s. They are used to treat allergic conditions and are very safe. The newer generation antihistamines have even less side effects compared to first generation or old antihistamines. ...Read more

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When should you take an antihistamine?

Multiple reasons: Depending on the type of antihistamine used they can be used to treat things such as allergy symptoms, nausea, dizziness, motion sickness, anxiety, itching, and difficulty sleeping. ...Read more

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What are the common uses of antihistamine?

Antihistamine 4 itch: Antihistamines (ah) block histamine receptors and stop histamine from causing itching and swelling. They are mainly used to treat allergies and hives. Some are sedating; those are used as sleep aids. Many otc sleep meds contain Diphenhydramine (benadryl). ...Read more

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What is the best time to take an antihistamine?

Any time: You can take antihistamines any time of the day. Take them same time of day everyday. ...Read more

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Why young people more sensitive to antihistamine?

Not true: Everyone reacts to medications differently although the differences may be minor in most cases. There is no study showing that young people are more sensitive to antihistamine, especially the newer ones. ...Read more

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Can I die by taking too many antihistamine tablets?

Can I die by taking too many antihistamine tablets?

Taking lethal over: Dose would do that. Lethal overdoses of antihistamines are rare. Are you considering taking an overdose of antihistamines? If so, please get help right away. You can use national suicide hotlines 24/7 at 1-800-suicide (1-800-784-2433) or 1-800-273 – talk (1-800-273-8255). If you have accidentally taken too many antihistamines please contact 1-800-222-1222 (poison control hotline). Take care. ...Read more

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What is the safest antihistamine for long term use?

What is the safest antihistamine for long term use?

New generation ones: Antihistamines in general are very safe. New generation products (Zyrtec, Claritin, (loratadine) Allegra, Xyzal) are just as effective with less side effects than older antihistamines (Benadryl, chlorpheniramine, hydroxyzine). However, it would be important to address WHY a person needs to take antihistamines long term? Consult with an allergist to assist in identifying the cause of symptoms. ...Read more

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Is there an herb which can be used as an antihistamine?

Yes: Butterbur has antihistamine-like effects. It can be found at health food stores. ...Read more

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Help please? What is a good yr round OTC antihistamine?

Antihistamine: All are good, zyrtec, allegra and claritin, (loratadine) but you should see an allergist if you need medicine all year round ...Read more

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Can you tell me what is the best medicine for antihistamine?

Can you tell me what is the best medicine for antihistamine?

New generation ones: The new generation antihistamines include Claritin, Zyrtec, Allegra and Xyzal (levocetirizine). These are as effective as older antihistamines (Benadryl, hydroxyzine, chlorpheniramine). Each person may respond differently to the different products and therefore trying them one at a time can be helpful. Since they are over-the-counter and generic (except for Xyzal (levocetirizine)), they are affordable and available. ...Read more

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Is it possible to die from an overdose of antihistamine pills?

Is it possible to die from an overdose of antihistamine pills?

Which one: First generation antihistamines are sedating, second generation ones are not, overdosing on the latter hardly kills, but may cause sedation. Overdosing on first generation antihistamines may be more of a problem, but again they are safe in high doses. ...Read more

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How many milligrams of antihistamine can a person take at one time?

Unclear: Different antihistamines have different potencies. 10 mg of Zyrtec is equivalent to 180mg of Allegra (fexofenadine). Mg doseage as in all medicines are drug specific. In regard to toxic levels, each has it's own known limit. However too much antihistamine can lead to deadly arrythmias/ Please use the recommended dose. ...Read more

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Is vistral and antihistamine the same or are they common medication?

Is vistral and antihistamine the same or are they common medication?

Antihistamine: Any medication that blocks chemical histamine, which causes allergy, is antihistamine. Vistaril (hydroxyzine) is one of these antihistamines. It is also used for sleep and sedation. ...Read more