Doctor insights on:
1st Generation Antihistamines
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
Whats 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 moreSee 1 more doctor answer
Allergic rhinitis and sinusitis. Went from loratadine claratin To Zyrtec To finally Xyzal (levocetirizine). The first 2 meds didn't help much. Is Xyzal (levocetirizine) more effective?
Allergy treatment: Basically, claritin, loratidine, zyrtec, allegra and xyzal (levocetirizine) are all 2nd generation antihistamines. If your symptoms are not controlled on these, you may need to be given intranasal steroids like flonase, nasonex or other treatments like singular, and also trying regular nasal saline. If still no improvement, time to see the allergist. ...Read more
Depends: Both Allegra and Claritin (loratadine) are antihistamines. They also come as "d" products which means they also contain a decongestant. The d products should not be taken more than prescribed. The antihistamine products are sometime recommended to be taken on the same day in the case of hives not controlled by only one. This should only be at the recommendation of your physician. ...Read moreSee 1 more doctor answer
Yes, but why: While it is best to avoid high doses of "d" which is pseudoephedrine-decongestant, an extra dose of Allegra (fexofenadine) is unlikely to be harmful. However, if a person needs extra medication, then it is best to do it under the direction of a physician and probably an allergist to assist in identifying the cause of the allergy. There are better ways to manage allergies than doubling up! ...Read more
Whats the best antihistamine for my 12y/o chronic sinusitis allegra Claritin zyrtec or Benadryl (diphenhydramine) and what dose ?
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
20 weeks preg. No sleep x 6 nights, severe nasal congestion. Is sudafed (pseudophedrine) best OTC choice? Safe? Better than sudafed pe (phenylephrine)?
See bellow: For allergic disorders in pregnancy: category a • doxylamine category b • Benadryl (diphenhydramine)-3rd trimester, Chlor-Trimeton (chlorpheniramine), cyproheptadine, gastrocrom (cromolyn sodium), singulair (montelukast), xyzal (levocetirizine), zyrtec (cetirizine hcl). ...Read moreSee 1 more doctor answer
Took a Claritin (loratadine) D 24 hrs 10 hours ago, forgot and took a allergy sinus med with acetaminophen, phenylephrine and diphenhydramine. Am I in danger?
Probably yes: Officially, that test is conclusive at 28 days. It's probably conclusive at 25 days, but to be absolutely certain, have another test in a week or so. ...Read more
6 hrs ago had Allergic reaction to bee sting, emt gave Benadryl, (diphenhydramine) then doctors at hospital gave prednisone and pepcid, Can next dose benadryl (diphenhydramine) b taken?
Yes: If you feel you still need it, but don't exceed recommended daily dose for diphenhydramine from all sources (300 mg /day), depends on the reaction too was it a local or whole body reaction? keep taking the benadryl for the next 24 -48 hours every 4-6 hours as needed 25- 50 mg , don't drive, and take the medicines prescribed at ER, if it was a whole body reaction, see an allergist, take care ...Read moreSee 1 more doctor answer
If allergic to 1 antihistamine, am i allergc to all? Have seen a few hives after benadryl, (diphenhydramine) xyzal, & now allegra. Coincidence or true allergy?
PROBABLY COINCIDENT: It is not possible to be allergic to all antihistamines and these are all different componds you listed.Benadryl, (diphenhydramine) xyzal and allegra.I will like to know what you call allergy, what are the symptoms and what kind of rash if any with these three antihistamine. It is possible but this kind of allergy will be considered rare consult your doctor who treated your allergies in first place;may beallergist. ...Read moreSee 2 more doctor answers
Was on xyzal (levocetirizine) for med allergies & chronic hives. Didn't like it so now trying allegra. Will allegra protect me during an alrgc reaction just as well?
Yes: Claritin (loratadine) and zyrtec are both oral antihistamine agents that block the effects of histamine on what is called the h1 receptor. By doing this, they reduce the release of histamine, a substance that causes itching, runny nose, and sneezing. Zyrtec blocks the receptor a bit better, but the clinical effect of the medications is roughly the same. Zyrtec may cause some drowsiness, but may last longer. ...Read moreSee 1 more doctor answer
Yes, but why: Zyrtec, Claritin (loratadine) and Allegra are all new generation antihistamines. While there is no contraindication to taking them on the same day, usually it is not necessary. If symptoms are not controlled, consider seeing an allergist to identify the trigger---with allergen avoidance, comes less symptoms and less medication! ...Read more
Yes, antihistamine: Zyrtec (cetirizine) *is* an antihistamine. Zyrtec (cetirizine) is an antihistamine used for treating allergy symptoms and itching due to hives. There are no other ingredients in zyrtec; however, zyrtec-d, a separate formulation, has in addition to the antihistamine a decongestant. ...Read moreSee 1 more doctor answer
Can I mix allegra (fexofenadine) & zyrtec for my allegy relief if allegra (fexofenadine) alone is not enough?
You could, but: They do exactly the same thing so taking both is just like taking a double dose of one. Instead, you should try something from a different medication category, like a prescription nasal steroid spray. ...Read more
Dx w/ chronic sinusitis. Dr says try Zyrtec (cetirizine) & flunisolide 2 wks minimum & wait on allergy tests. F/u appt in May. Meds not helping after 5 days.
Call doc again: If you have sinusitis which has not responded to flunisolide after 5 days, you likely need an antibiotic now. I don't see how the finding from allergy test would alter your current treatment (for long term , likely yes). In the meanwhile try saline irrigation on the sinuses. ...Read more