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September 19, 2020

Cetirizine indications and dosage in dermatology

Indications of Cetirizine in dermatology

Acute urticaria.
Chronic urticaria : Higher doses may be required (e.g., 20 to 40 mg of cetirizine each day)
Cholinergic urticaria: 20 mg daily.
Cold urticaria.
Heat urticaria.
Solar urticaria.
Mastocytosis : fexofenadine 360 mg in the morning and up to 40 mg of cetirizine at night in adults.
Eosinophilic folliculitis.

Dosage of Cetirizine in adults

5–10 mg PO qd.
RENAL DOSING : CrCl < 30: 5 mg PO qd.
HEPATIC DOSING: 5 mg PO qd.

Dosage of Cetirizine in chlidren

Here are the recommended cetirizine dosages for children:

Age of child	Recomedned dose
6-11 months	0.25 mg/kg (maximum of 2.5mg) taken orally once daily
1-2 years	2.5mg taken orally twice daily
2-6 years	5mg taken orally once daily or 2.5mg taken orally twice daily
6-12 years	10mg taken orally once daily or 5mg taken orally twice daily
12-18 years	10mg taken orally once daily

For chonic urticaria patients, the maximum daily dose of cetirizine can be increased up to four times the recommended amount. For instance, in children aged 6 years and above, the highest total daily dose of cetirizine is 40mg.

Mechanism of action

Cetirizine is a second-generation H1 histamine receptor blocker that is a carboxylic acid metabolite of the first-generation antihistamine hydroxyzine.
It also inhibits eosinophil chemotaxis and accumulation in the skin.
Cetirizine is a long acting, minimally sedating antihistamine.

Side effects

COMMON: somnolence, fatigue, dry mouth, pharyngitis, dizziness, abdominal pain, nausea, vomiting, diarrhea, headache, coughing, epistaxis,
bronchospasm.

RARE: hepatitis, hypersensitivity reaction, anorexia, flushing, increased salivation, urinary retention, cardiac failure, hypertension, palpitation,
tachycardia, abnormal coordination, ataxia, confusion, dysphonia, hyperesthesia, leg cramps, migraine, myelitis, paralysis, paresthesia, ptosis,
syncope, tremor, twitching, vertigo, visual field defect, constipation, dyspepsia, flatulence, gastritis, hemorrhoids, increased appetite, melena, rectal hemorrhage, stomatitis, tongue edema, tongue discoloration, cystitis,
dysuria, hematuria, polyuria, urinary incontinence, deafness, ear ache, ototoxicity, tinnitus, dehydration, diabetes, thirst, arthralgia, arthritis,
arthrosis, myalgia, muscle weakness, agitation, amnesia, anxiety, decreased libido, depression, emotional lability, euphoria, impaired concentration,
insomnia, nervousness, paranoia, bronchitis, dyspnea, pneumonia, increased sputum, sinusitis, upper respiratory tract infection, dysmenorrhea, breast pain, intermenstrual bleeding, leukorrhea, menorrhagia, vaginitis, lymphadenopathy, acne, alopecia, angioedema, bullous eruption, dermatitis, dry skin, eczema, furunculosis, hyperkeratosis, hypertrichosis, rash, photosensitivity, pruritus, purpura, seborrhea, urticaria, parosmia, ageusia, blindness, conjunctivitis, glaucoma, ocular hemorrhage, xeropthalmia, asthenia, back pain, face edema, fever, increased weight, pallor, nasal polyps, edema, rigors.

Contraindications

Hypersensitivity to drug/class.
Hypersensitivity to hydroxyzine.
Impaired liver or renal function.
Concurrent use of central nervous system depressants.

Interactions

INCREASED CENTRAL NERVOUS SYSTEM DEPRESSION: opiates, tramadol, antidepressants, antihistamines, antipsychotics, propoxyphene, barbiturates, benzodiazepines, droperidol, ethanol, meperidine, central alpha-2 agonists, meprobamate, metoclopramide, muscle relaxants, phenothiazines, promethazine, sedatives/hypnotics, thalidomide.
INCREASED RISK OF HYPERTENSION: central alpha-2 agonists (eg, methyldopa).

Pregnancy &Lactation

Pregnancy category B.
Current guidelines on urticaria support the use of cetirizine beyond the first trimester of pregnancy if the benefits of an antihistamine are considered to outweigh any risks of administration for an individual patient.
Lactation: Excreted in breast milk; small doses are accepted but large doses may cause drowsiness in infants and may decrease milk supply.

Precautions

Caution is advised at doses exceeding 10 mg daily.
High doses may be sedating in some patients.
Reduce dosage is recommended in patients with impaired liver and kidney function.
Avoid cetirizine or levocetirizine in patients who have experienced AGEP.

Drug Info

Cetirizine is the carboxylic acid metabolite of the first generation H1 antihistamine hydroxyzine.
Cetirizine is generally considered the most sedating of the second-generation H1 antihistamines.

Sources

Dermatology , Edited by Jean L. Bolognia , Julie V. Schaffer , Lorenzo Cerroni Fourth edition: Elsevier, 2018, ISBN 978–0‐7020–6275–9.
Griffiths, C., Barker, J., Bleiker, T. O., Chalmers, R., & Creamer, D. (Eds.). (2016). Rook’s textbook of dermatology. John Wiley & Sons.
Lebwohl, M. G., Heymann, W. R., Berth-Jones, J., & Coulson, I. (2013). Treatment of skin disease E-Book: comprehensive therapeutic strategies. Elsevier Health Sciences.
https://www.rch.org.au/clinicalguide/guideline_index/Urticaria/

Cetirizine indications and dosage in dermatology

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