Antihistamines
Description
Antihistamines are medications that have some similarities in structure to the histamines that cause allergic reactions. Histamines are released during allergic reactions. They cause sneezing, itching and watery mucus in the upper airway. Antihistamines work by attaching to the same receptors that histamines use to cause allergic symptoms. By occupying these sites, they effectively block histamines from causing allergic symptoms. Therefore antihistamines prevent the effects of histamine.
Use
Antihistamines are effective if you have allergies. If you have allergic asthma, antihistamines may be effective in controlling your upper respiratory allergies and therefore help control your asthma. These medications may or may not play a role in the treatment of sinus disease. Many commonly used over the counter and prescription antihistamines are listed below. Some are antihistamines alone while others are combination products with decongestants, mucolytics, or drying agents. Astelin® is currently the only antihistamine available for nasal use.
| Brand Name | Antihistamine |
| Actifed® Cold and Allergy Tablets* (OTC) | triprolidine 2.5mg |
| AccuHist® LA* (OTC) | chlorpheniramine 8mg |
| Alavert™ Tablets (OTC) | loratadine 10mg |
| Allegra® Tablets | fexofenadine 30, 60, 180mg |
| Allegra-D® (12 Hr and 24 Hr) Extended-Release Tablets* | fexofenadine 60, 180mg |
| AlleRx® Dose Pack PM Tab | chlorpheniramine 8mg |
| Antivert® Tabs | meclizine 12.5, 25, 50mg |
| Astelin® Nasal Spray | azelastine 137mcg/spray |
| Atarax® Tablets and Syrup | hydroxyzine 10, 25, 50mg |
| Atrohist® Pediatric Capsules | chlorpheniramine 4mg |
| Atrohist® LA Tab | chlorpheniramine 8mg |
| Benadryl® Allergy Chewables (OTC) | diphenhydramine 12.5mg |
| Benadryl® Allergy Kapseal Capsules (OTC) | diphenhydramine 25mg |
| Benadryl® Allergy Liquid Medication (OTC) | diphenhydramine 12.5mg/5mL |
| Benadryl® Allergy Ultratab Tablets (OTC) | diphenhydramine 25mg |
| Benadryl® Allergy/Congestion LiquidMedication* (OTC) | diphenhydramine 12.5mg/5mL |
| Benadryl® Allergy/Congestion Tablets* (OTC) | diphenhydramine 25mg |
| Chlor-Trimeton® Tablets (OTC) | chlorpheniramine 4, 8, 12mg |
| Clarinex®/Clarinex-D® | desloratadine 5mg |
| Clarinex Reditabs® | desloratadine 5mg |
| Clarinex® Syrup | desloratadine 0.5mg/mL |
| Claritin-D® 12Hr ER Tablets* (OTC) | loratadine 5mg |
| Claritin-D® 24Hr ER Tablets* (OTC) | loratadine 10mg |
| Claritin Reditabs® (OTC) | loratadine 10mg |
| Claritin® Syrup (OTC) | loratadine 1mg/mL |
| Claritin® Tablets (OTC) | loratadine 10mg |
| Dallergy tab | chlorpheniramine 4mg |
| Dallergy tab (extended-release) | chlorpheniramine 12mg |
| Dallergy syrup | chlorpheniramine 2mg |
| Deconamine® Caps (sustained-release) | chlorpheniramine 8mg |
| Deconamine® Tablets | chlorpheniramine 4mg |
| Deconamine® Syrup | chlorpheniramine 2mg |
| Dimetapp® Cold & Allergy Chewable Tablets* (OTC) | brompheniramine 1mg |
| Dimetapp® Elixir* (OTC) | brompheniramine 2mg |
| Dimetapp® Tablets* (OTC) | brompheniramine 4mg |
| Duradryl® Syrup* (OTC) | chlorpheniramine 2mg |
| Dura-Vent/DA® Tablets* | chlorpheniramine 8mg |
| Extendryl® Chewable Tablets* | chlorpheniramine 2mg |
| Extendryl® Sr. T.D. Capsules* | chlorpheniramine 8mg |
| Extendryl® Jr. Capsules* | chlorpheniramine 4mg |
| Extendryl® Syrup* | chlorpheniramine 2mg/5mL |
| Nolahist® Tablets* dye and alcohol free | phenindamine tartrate 25mg |
| Periactin® Syrup | cyproheptadine 2mg/5mL |
| Periactin® Tablets | cyproheptadine 4mg |
| Phenergan® Suppositories | promethazine 12.5, 25, 50mg |
| Phenergan® Syrup | Fortis promethazine 25mg/5mL |
| Phenergan® Syrup Plain | promethazine 6.25mg/5mL |
| Phenergan® Tablets | promethazine 12.5, 25, 50mg |
| Phenergan® with Codeine | promethazine 6.25mg/5mL |
| Poly-Histine® D ped caps* | pyrilamine 8mg |
| Poly-Histine® D elixir* | pyrilamine 4mg |
| Rondec® Oral Drops (1 - 18 months)* | carbinoxamine 2mg |
| Rondec® DM Oral Drops (1 - 18 months)* | carbinoxamine 2mg |
| Rondec® Syrup* | brompheniramine 4mg/5mL |
| Rynatan® Tablets* | chlorpheniramine 8mg |
| Rynatan® Suspension* | chlorpheniramine 2mg/5mL |
| Rynatuss® Tablets* | chlorpheniramine 5mg |
| Rynatuss® Pediatric Suspension | chlorpheniramine 4mg/5mL |
| RYNA®-12 | pyrilamine 30mg |
| Semprex-D® Capsules* | acrivastine 8mg |
| Sinequan® (doxepin)** | doxepin 10, 25, 50, 75, 100mg |
| caps & oral | concentrate 10mg/mL |
| Sinutab® Sinus Allergy Tablets (OTC) | chlorpheniramine 2mg |
| Tavist-1® 12 Hour Relief Tablets (OTC) | clemastine fumarate 1.34mg |
| Trinalin® Repetab | azatadine 1mg |
| Viravan-S®* | pyrilamine 30mg/5mL |
| Viravan-T®* | pyrilamine 25mg |
| Zyrtec® Chewable Tablets | cetirizine 5, 10mg |
| Zyrtec® Syrup | cetirizine 5mg/5mL |
| Zyrtec® Tablets | cetirizine 10mg |
| Zyrtec D® Tablets* | cetirizine 5mg |
* Medication also includes a decongestant OTC = over the counter
**Medication also has antidepressant activity (at higher doses)
Antihistamine and Decongestant Combinations
Brand Name
Ingredients
Allegra-D® Extended Release Tablets
fexofenadine, 60mg
pseudoephedrine 120mg
AlleRx® Dose Pack AM Tab
pseudoephedrine 120mg
methscopolamine 2.5mg
PM Tab
chlorpheniramine 8mg
methscopolamine 2.5mg
Atrohist® Pediatric Capsules
chlorpheniramine 4mg
pseudoephedrine 60mg
Atrohist® LA Tab
chlorpheniramine 8mg
phenylephrine 20mg
hyoscyamine 0.19mg
scopolamine hydrobromide 0.01mg
Bellahist-D® LA
chlorpheniramine 8mg
phenylephrine 20mg
hyoscyamine 0.19mg
scopolamine 0.01mg
Clarinex D®
desloratadine 5mg
pseudoephedrine 240mg
Dallergy® Tab
chlorpheniramine 4mg
phenylephrine 10mg
methscopolamine 1.25mg
Dallergy® Tab (extended-release)
chlorpheniramine 12mg
phenylephrine 20mg
methscopolamine 2.5mg
Dallergy® Syrup
chlorpheniramine 2mg
phenylephrine 10mg/5mL
methscopolamine 0.625mg
Deconamine® Caps (sustained-release)
chlorpheniramine 8mg
pseudoephedrine 120mg
Deconamine® Tab
chlorpheniramine 4mg
pseudoephedrine 60mg
Deconamine® Syrup
chlorpheniramine 2mg/5mL
pseudoephedrine 30mg/5mL
Extendryl® Chewable Tablets
chlorpheniramine 2mg
phenylephrine 10mg
methscopolamine 1.25mg
Extendryl® Sr. T.D. Capsules
chlorpheniramine 8mg
phenylephrine 20mg
methscopolamine 2.5mg
Extendryl® Jr. Capsules
chlorpheniramine 4mg
phenylephrine 10mg
methscopolamine 1.25mg
Extendryl® Syrup
chlorpheniramine 2mg/5mL
phenylephrine 10mg/5mL
methscopolamine 1.25mg/5mL
Rondec® Oral Drops
carbinoxamine 2mg/5mL
pseudoephedrine 25mg/5mL
Rondec® Syrup
brompheniramine 4mg/5mL
pseudoephedrine 45mg/5mL
Ryna 12X® Suspension
pyrilamine 30mg/5mL
phenylephrine 5mg/5mL
Rynatan® Tablets
chlorpheniramine 9mg
phenylephrine 25mg
Rynatan® Suspension
chlorpheniramine 4mg/5mL
phenylephrine 5mg/mL
Rynatuss® Tablets
chlorpheniramine 5mg
ephedrine 10mg
phenylephrine 10mg
carbetapentane 60mg
Rynatuss® Pediatric Suspension
chlorpheniramine 4mg/5mL
ephedrine 5mg/5mL
phenylephrine 5mg/5mL
carbetapentane 30mg/5mL
Semprex®-D Capsules
acrivastine 8mg
pseudoephedrine 60mg
Viravan® T Chewables
pyrilamine 30mg
phenylephrine 25mg
Viravan® S Suspension
pyrilamine 30mg/5mL
phenylephrine 12.5mg/5mL
Zyrtec-D® Tablets
cetirizine 5mg
pseudoephedrine 120mg
Antihistamine/Mast Cell Stabilizer
Astelin® Nasal Spray
azelastine 137mcg/spray
Risks and Precautions
Older antihistamines (for example, Benadryl®) have a drying effect. This drying effect can thicken secretions. This can lead to sinus problems. Second generation antihistamine products like Claritin, Allegra, Clarinex, Zyrtec and generic loratadine do not have drying effects.
Some common side effects of antihistamines include:
- Fatigue and drowsiness (classical antihistamines)
- Dry mouth, nausea, gastritis, stomach ache (classical antihistamines)
- Dizziness, excitement, personality changes, irritability
- Central nervous system depression if used with alcohol or other drugs
- Tendency to worsen glaucoma, urinary tract obstructions (classical antihistamines)
- Abnormalities of the blood
- Slowed reflexes (classical antihistamines)
News Alerts and Recalls
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