More frequently reported side effects include: abdominal pain, drowsiness, and fatigue. See below for a comprehensive list of adverse effects.

Applies to cetirizine: oral solution, oral tablets and chewable tablets

Side effects include:

Adults and children ≥12 years of age: Somnolence, fatigue, dry mouth. Insomnia reported with cetirizine hydrochloride-pseudoephedrine hydrochloride fixed combination.

Children 2–11 years of age: Headache, pharyngitis, abdominal pain.

Children 6 months to 2 years of age: Irritability, fussiness, insomnia, fatigue, malaise.

Applies to cetirizine: oral capsule, oral liquid, oral syrup, oral tablet, oral tablet chewable, oral tablet dispersible

The most commonly reported side effects include somnolence, dizziness, and headache.

Very common (10% or more): Somnolence (up to 14.3%), headache (up to 14%)

Common (1% to 10%): Dizziness

Frequency not reported: Altered sense of taste, paresthesia, hypertonia, tremor, abnormal coordination/incoordination, ataxia, hyperesthesia, hyperkinesia, hypoesthesia, migraine, paralysis, twitching, parosmia, taste loss/perversion

Postmarketing reports: Convulsions, dysgeusia, dyskinesia, dystonia, syncope, amnesia, vertigo, memory impairment

Common (1% to 10%): Dry mouth, nausea, diarrhea, vomiting, abdominal pain

Uncommon (0.1% to 1%): Dyspepsia

Frequency not reported: Tongue disorder, constipation, flatulence, increased salivation, aggravated tooth caries, eructation, gastritis, hemorrhoids, melena, rectal hemorrhage, stomatitis/ulcerative stomatitis, tongue discoloration/edema, enlarged abdomen

Common (1% to 10%): Pharyngitis, rhinitis, coughing, epistaxis

Frequency not reported: Dyspnea, respiratory disorder, bronchospasm, upper respiratory tract infection, dysphonia, bronchitis, hyperventilation, increased sputum, pneumonia, sinusitis, nasal polyp

Common (1% to 10%): Fatigue

Frequency not reported: Earache, tinnitus, fever, pain, rigor, thirst, deafness, ototoxicity, accidental injury, face edema, leg edema, malaise

Postmarketing reports: Asthenia, stillbirth

Common (1% to 10%): Insomnia

Frequency not reported: Nervousness, impaired concentration, confusion, decreased libido, abnormal thinking, anxiety, depersonalization, emotional lability, euphoria, paroniria, sleep disorder

Postmarketing reports: Agitation, aggression/aggressive reaction, depression, hallucination, tic, suicidal ideation/suicide

Very rare (less than 0.01%): Myelitis

Frequency not reported: Back pain, myalgia, arthralgia, bone disorder/fracture, leg cramps, arthritis, arthrosis, muscle weakness

Frequency not reported: Pruritus/intense itching, increased sweating, acne, alopecia, bullous eruption, dermatitis, dry skin, eczema, erythematous rash, furunculosis, hyperkeratosis, hypertrichosis, maculopapular rash, photosensitivity/photosensitivity toxic reaction, purpura, seborrhea, skin disorder/nodule

Postmarketing reports: Rash, urticaria, angioneurotic edema, fixed drug eruption, acute generalized exanthematous pustulosis (AGEP)

Frequency not reported: Eye abnormality, periorbital edema, abnormal vision, eye pain, conjunctivitis, ptosis, visual field defects, blindness, glaucoma, ocular hemorrhage, xerophthalmia, periorbital edema/eye swelling

Postmarketing reports: Accommodation disorder/loss of accommodation, blurred vision, oculogyration, orofacial dyskinesia

Frequency not reported: Polyuria, urinary retention, urinary tract infection, dysmenorrhea, hematuria, micturition frequency, urinary incontinence, female breast pain, intermenstrual bleeding, leukorrhea, menorrhagia, vaginitis

Postmarketing reports: Dysuria, enuresis

Frequency not reported: Flushing, palpitations, tachycardia, edema/general edema, chest pain, cardiac failure, hypertension, hot flashes, peripheral edema, pallor

Postmarketing reports: Severe hypotension

Frequency not reported: Increased appetite, anorexia, increased weight, dehydration, diabetes mellitus

Frequency not reported: Reversible transaminase elevations

Postmarketing reports: Abnormal hepatic function (increased transaminases, alkaline phosphatase, GGT, bilirubin), cholestasis, hepatitis

Frequency not reported: Allergic reactions/delayed allergic reactions

Postmarketing reports: Hypersensitivity, anaphylactic shock

Frequency not reported: Lymphadenopathy

Postmarketing reports: Thrombocytopenia, hemolytic anemia

Frequency not reported: Cystitis

Postmarketing reports: Glomerulonephritis