II. Indications
III. Pathophysiology
- Second Generation Antihistamine
IV. Preparations: Advantages and Disadvantages
- Fexofenadine (Allegra)
- Least sedating, even in higher doses
- Loratadine (Claritin)
- Sedating at higher doses
- Less potent than Allegra and Zyrtec
- Cetirizine (Zyrtec) and Levocetirizine (Xyzal)
- May be sedating even at normally recommended doses (Hydroxyzine analog); reported by 10% of patients
- More rapid onset than other Non-Sedating Antihistamines (1 hour instead of 3 hours)
- Only significant if Antihistamine is taken as needed (instead of daily)
V. Preparations: Oral by Age Restrictions
- Age 6 months and older
- Cetirizine (Zyrtec, Pregnancy category B)
- Desloratadine (Clarinex, Pregnancy category C)
- Fexofenadine (Allegra, Pregnancy category C)
- Age 2 years and older
- Loratadine (Claritin, Pregnancy category B)
- Age 12 years and older
- Levocetirizine (Xyzal, Pregnancy category B)
VI. Preparations: Oral
- Fexofenadine (Allegra, OTC, Tabs 30-60-180 mg, Dissolving 30 mg, Suspension 30 mg/5ml)
- Adult Dose (ages 12 and over): 60 mg orally twice daily or 180 mg orally daily
- Child Dose (ages 6-11 years): 30 mg orally twice daily
- Low sedation and highly effective
- Loratadine (Claritin, OTC, tabs 10 mg, Dissolving 5-10 mg, Syrup 1mg/ml)
- Adult Dose (ages 6 and over): 10 mg orally daily
- Child Dose (ages 2-5 years): 5 mg orally daily
- Cetirizine (Zyrtec, OTC, Tabs or Chewables 5-10 mg, Syrup 5 mg/5 ml)
- Adult Dose (includes ages 6-11): 5 or 10 mg orally daily
- Child Dose (ages 2-5 years): 2.5 mg orally daily to twice daily
- Infant Dose (ages 6 months to 2 years): 2.5 mg orally daily
- Levocetirizine (Xyzal, OTC, Scored Tabs 5 mg, solution 2.5 mg/5ml)
- Active isomer of Cetirizine (Zyrtec)
- Adult Dose (ages 12 and over): 5 mg orally daily
- Child Dose (ages 6-11 years): 2.5 mg orally daily
- Desloratadine (Clarinex, prescription only, tabs 5 mg, Dissolving 2.5-5 mg, Syrup 0.5 mg/ml)
- Adult Dose (ages 12 and over): 5 orally daily
- Child Dose (ages 6-11 years): 2.5 mg orally daily to twice daily
- Preschool Dose (ages 12 months to 5 years): 1.25 mg orally daily
- Infant Dose (ages 6-12 months): 1 mg orally daily
VII. Preparations: Nasal
- Azelastine (Astelin) 1-2 sprays per nostril twice daily (ages 5 and over)
- Olopatadine (Patanol) 2 sprays per nostril twice daily (ages 12 and over)
VIII. Safety: Pregnancy and Lactation
- Contraindicated in Lactation
- Pregnancy Class B agents (other agents are Category C)
- Cetirizine (Zyrtec)
- Loratadine (Claritin)
- Levocetirizine (Xyzal)
- Pregnancy Class C agents
- Fexofenadine (Allegra)
- Appears as safe in pregnancy as other Non-Sedating Antihistamines that are category B (Cetirizine, Loratadine)
- Andersson (2020) JAMA Pediatr 174(8): e201316 [PubMed]
- Fexofenadine (Allegra)
IX. Drug Interactions
- Historical Only: Astemizole (Hismanal) and Terfenadine (Seldane)
- Prolong QT Interval
- Contraindicated with Erythromycin, Ketoconazole
- Resulted in fatal Arrhythmias in multiple cases
- Fexofenadine
- Absorption decreased by orange juice, Grapefruit juice, apple juice (separate by at least 4 hours)
X. References
- Howarth (1999) J Allergy Clin Immunol 104:927 [PubMed]
- Walsh (2001) Drugs 61:207 [PubMed]
- (2001) Med Lett Drugs Ther 43(1103):35
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Related Studies
| Loratadine (on 6/18/2017 at Walmart.com) | ||
| Loratadine 10mg | #30 tablets for $4.00 | $0.13 each |
| Loratadine 10mg | #90 tablets for $10.00 | $0.11 each |
| loratadine (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| LORATADINE 10 MG TABLET | Generic OTC | $0.06 each |
| LORATADINE 5 MG/5 ML SOLN | Generic OTC | $0.04 per ml |
| LORATADINE 5 MG/5 ML SYRUP | Generic OTC | $0.04 per ml |
| LORATADINE ALLERGY 5 MG/5 ML | Generic OTC | $0.04 per ml |
| LORATADINE HIVES 5 MG/5 ML | Generic OTC | $0.04 per ml |
| LORATADINE-D 12 HOUR TABLET | Generic OTC | $0.76 each |
| LORATADINE-D 24HR TABLET | Generic OTC | $0.42 each |
| cetirizine (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| CETIRIZINE HCL 1 MG/ML SOLN | Generic | $0.02 per ml |
| CETIRIZINE HCL 1 MG/ML SYRUP | Generic | $0.02 per ml |
| CETIRIZINE HCL 10 MG TABLET | Generic OTC | $0.07 each |
| CETIRIZINE HCL 5 MG CHEW TAB | Generic OTC | $2.53 each |
| CETIRIZINE HCL 5 MG TABLET | Generic OTC | $0.06 each |
| CETIRIZINE-PSE ER 5-120 MG TAB | Generic OTC | $0.65 each |
| fexofenadine (on 5/17/2017 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| FEXOFENADINE HCL 180 MG TABLET | Generic OTC | $0.34 each |
| FEXOFENADINE HCL 30 MG/5 ML | Generic OTC | $0.05 per ml |
| FEXOFENADINE HCL 60 MG TABLET | Generic OTC | $0.33 each |
| FEXOFENADINE-PSE ER 60-120 TAB | Generic OTC | $0.71 each |
Ontology: Cetirizine (C0055147)
| Definition (NCI) | Cetirizine is a metabolite of hydroxyzine and a selective peripheral histamine H1-receptor antagonist. It is used for symptomatic treatment of seasonal and perennial allergic rhinitis and for chronic urticaria. (NCI) |
| Definition (MSH) | A potent second-generation histamine H1 antagonist that is effective in the treatment of allergic rhinitis, chronic urticaria, and pollen-induced asthma. Unlike many traditional antihistamines, it does not cause drowsiness or anticholinergic side effects. |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | D017332 |
| SnomedCT | 108655000, 372523007 |
| English | Cetirizine, (2-(4-((4-Chlorophenyl)phenylmethyl)-1-piperazinyl)ethoxy)acetic Acid, Acetic acid, (2-(4-((4-chlorophenyl)phenylmethyl)-1-piperazinyl)ethoxy)-, cetirizine, Cetirizine [Chemical/Ingredient], CETIRIZINE, Cetirizine (product), Cetirizine (substance) |
| Swedish | Cetirizin |
| Czech | cetirizin |
| Finnish | Setiritsiini |
| Russian | TSETIRIZIN, ЦЕТИРИЗИН |
| Japanese | セチリジン, セテリジン |
| Polish | Cetyryzyna |
| Spanish | cetiricina, cetirizina (producto), cetirizina (sustancia), cetirizina, Cetirizina |
| French | Cétirizine |
| German | Cetirizin |
| Italian | Cetirizina |
| Portuguese | Cetirizina |
Ontology: Loratadine (C0065180)
| Definition (NCI) | A piperidine histamine H1-receptor antagonist with anti-allergic properties and without sedative effects. Loratadine blocks the H1 histamine receptor and prevents the symptoms that are caused by histamine activity on capillaries, bronchial smooth muscle, and gastrointestinal smooth muscle, including vasodilatation, increased capillary permeability, bronchoconstriction, and spasmodic contraction of gastrointestinal smooth muscle. Loratadine does not cross the blood-brain barrier and does not cause central nervous system effects. |
| Definition (MSH) | A second-generation histamine H1 receptor antagonist used in the treatment of allergic rhinitis and urticaria. Unlike most classical antihistamines (HISTAMINE H1 ANTAGONISTS) it lacks central nervous system depressing effects such as drowsiness. |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | D017336 |
| SnomedCT | 108652002, 386884002 |
| LNC | LP21145-5, MTHU012784 |
| English | Loratadine, 4-(8-Chloro-5,6-dihydro-11H-benzo(5,6)cyclohepta(1,2-b)pyridin-11-ylidene)-1-piperidinecarboxylic Acid Ethyl Ester, 1-Piperidinecarboxylic acid, 4-(8-chloro-5,6-dihydro-11H-benzo(5,6)cyclohepta(1,2-b)pyridin-11-ylidene)-, ethyl ester, loratadine (medication), 1-Piperidinecarboxylic acid, 4-(8-chloro-5,6-dihydro-11H-benzo(5,6)cyclohepta(1,2-b)pyridin-11-ylidene)-, Ethyl Ester, loratadine, LORATADINE, Loratadine [Chemical/Ingredient], Loratadine product, Loratadine (product), Loratadine (substance) |
| Swedish | Loratadin |
| Czech | loratadin |
| Finnish | Loratadiini |
| Russian | LORATADIN, ЛОРАТАДИН |
| Japanese | ロラタジン |
| Polish | Loratadyna |
| Spanish | loratadina (producto), loratadina (sustancia), loratadina, Loratadina |
| French | Loratadine |
| German | Loratadin |
| Italian | Loratadina |
| Portuguese | Loratadina |
Ontology: Zyrtec (C0162723)
| Definition (CHV) | brand name of an allergy medicine |
| Definition (CHV) | brand name of an allergy medicine |
| Definition (CHV) | brand name of an allergy medicine |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | D017332 |
| English | Zirtek, zyrtec [brand name], zirtek, zyrtec, ZyrTEC, Zyrtec, Pfizer Brand of Cetirizine Dihydrochloride, Pfizer Consumer Healthcare Brand of Cetirizine Dihydrochloride, Reactine, UCB Brand of Cetirizine Dihydrochloride, UCB Pharma Brand of Cetirizine Dihydrochloride, United Drug Brand of Cetirizine Dihydrochloride, Voltric |
Ontology: fexofenadine (C0296800)
| Definition (NCI_NCI-GLOSS) | A drug used to treat certain allergy symptoms. It blocks a chemical released during an allergic response that causes itching, sneezing, runny nose, wheezing, and watery eyes. It is a type of antihistamine. |
| Definition (NCI) | A second generation, long-lasting selective histamine H1 receptor antagonist with antiinflammatory property. Fexofenadine is a highly selective and reversible competitor at peripheral H1 histamine receptors in the gastrointestinal (GI) tract, blood vessels, and bronchial smooth muscle. This agent interferes with mediators release from mast cells either by inhibiting calcium ion influx across mast cell/basophil plasma membrane or by inhibiting intracellular calcium ion release within the cells. In addition fexofenadine may also inhibit the late-phase allergic reaction by acting on leukotrienes or prostaglandins, or by producing an anti-platelet activating factor effect. Overall, this agent blocks the actions of endogenous histamine, thereby leads to temporary relief of the negative symptoms associated with histamine and achieve effects such as decreased vascular permeability, reduction of pruritus and localized smooth muscle relaxation. |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | C093230 |
| SnomedCT | 108650005, 372522002 |
| LNC | LP101033-1, MTHU036232 |
| English | alpha-(4-(1-carboxy-1-methylethyl)phenyl)-4-hydroxydiphenylmethyl-1-piperidinebutanol, fexofenadine, fexofenadines (medication), fexofenadines, FEXOFENADINE, fexofenadine [Chemical/Ingredient], Fexofenadine, Fexofenadine (product), Fexofenadine (substance) |
| Spanish | fexofenadina (producto), fexofenadina (sustancia), fexofenadina |
Ontology: Claritin (C0701055)
| Definition (CHV) | brand name of loratadine |
| Definition (CHV) | brand name of loratadine |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | D017336 |
| English | claritin, claritin [brand name], Claritin |
Ontology: Allegra (C1110594)
| Definition (CHV) | brand name of an allergy medicine |
| Definition (CHV) | brand name of an allergy medicine |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | C093230 |
| English | telfast, allegra, allegra [brand name], Telfast, Aventis Behring brand of fexofenadine hydrochloride, Aventis Pharma brand of fexofenadine hydrochloride, Aventis brand of fexofenadine hydrochloride, Hoechst brand of fexofenadine hydrochloride, Allegra |
Ontology: Histamine H1 Antagonists, Non-Sedating (C1136312)
| Definition (MSH) | A class of non-sedating drugs that bind to but do not activate histamine receptors (DRUG INVERSE AGONISM), thereby blocking the actions of histamine or histamine agonists. These antihistamines represent a heterogenous group of compounds with differing chemical structures, adverse effects, distribution, and metabolism. Compared to the early (first generation) antihistamines, these non-sedating antihistamines have greater receptor specificity, lower penetration of BLOOD-BRAIN BARRIER, and are less likely to cause drowsiness or psychomotor impairment. |
| Concepts | Pharmacologic Substance (T121) |
| MSH | D039563 |
| SnomedCT | 349956006, 372624008 |
| French | Anti-histaminiques H1 non sédatifs, Antihistaminiques de seconde génération, Anti-histaminiques de seconde génération, Antagonistes de l'histamine H1 non sédatifs, Antihistaminiques H1 non sédatifs |
| Swedish | Histamin H1-blockerare, icke-sederande |
| English | HISTAMINE H1 ANTAG NON SEDATING, HISTAMINE ANTAGONISTS H 001 NON SEDATING, antihistamines non sedating, non-sedating antihistamine, second generation antihistamine, antihistamines second generation, antihistamine non sedating, second generation antihistamines, Antihistamines, Second Generation, H1 Antihistamines, Non Sedating, H1 Antihistamines, Non-Sedating, Histamine H1 Antagonists, Non Sedating, Histamine H1 Antagonists, Non-Sedating, Non-Sedating H1 Antihistamines, Second Generation Antihistamines, Second Generation H1 Antagonists, Non-sedating antihistamine, Non-sedating antihistamine (product), Non-sedating antihistamine (substance), Histamine1 (H1) Blocking Agents, Mildly/Non-sedating |
| Czech | histaminové H1-receptory - blokátory nesedativní, histamin H1 - antagonisté nesedativní |
| Finnish | Väsyttämättömät antihistamiinit |
| German | H1-Antagonisten der zweiten Generation, HISTAMIN ANTAGONISTS H 001 NICHT SEDIERENDE, Histamin-H1-Antagonisten, nicht sedierende |
| Russian | GISTAMINA H1 ANTAGONISTY NESEDATIVNYE, ГИСТАМИНА H1 АНТАГОНИСТЫ НЕСЕДАТИВНЫЕ |
| Japanese | 非鎮静性ヒスタミンH1拮抗剤, 非鎮静性H1抗ヒスタミンザイ, H1抗ヒスタミンザイ-非鎮静性, ヒスタミンH1拮抗剤-非鎮静性 |
| Polish | Antagoniści histaminy H1 bez działania uspokajającego, Antyhistaminiki H1 II generacji, Leki antyhistaminowe H1 II generacji, Leki przeciwhistaminowe H1 II generacji |
| Portuguese | Antagonistas dos Receptores Histamínicos H1 não Sedativos, Antagonistas dos Receptores H1 da Histamina não Sedativos, Antagonistas dos Receptores H1 de Histamina não Sedativos |
| Spanish | Antagonistas de los Receptores Histamínicos H1 no Sedantes, Antagonistas de los Receptores H1 de la Histamina no Sedantes, Antagonistas de los Receptores H1 de Histamina no Sedantes, antihistamínico no sedante (producto), antihistamínico no sedante (sustancia), antihistamínico no sedante |
| Italian | Antagonisti dell'istamina H1, non sedativi |
