Antihistamines

All antihistamines are of potential value in the treatment of nasal allergies, particularly seasonal allergic rhinitis (hay fever), and they may be of some value in vasomotor rhinitis. They reduce rhinorrhoea and sneezing but are usually less effective for nasal congestion. Antihistamines are used topically in the eye, in the nose and on the skin. Oral antihistamines are also of some value in preventing urticaria and are used to treat urticarial rashes, pruritus, and insect bites and stings; they are also used in drug allergies. Injections of chlorphenamine (chlorpheniramine) or promethazine are used as an adjunct to adrenaline (epinephrine) in the emergency treatment of anaphylaxis and angioedema.

Sedating Antihistamines

Chlorpheniramine maleate:

Indications: Allergic Conjunctivitis, Allergic Rhinitis, Anaphylaxis Adjunct, Dermatographic Urticaria, Nasal Congestion, Pruritus of Skin, Rhinorrhea, Sneezing, Urticaria, Vasomotor Rhinitis.

Contraindications: Acute Asthma Attack, Narrow Angle Glaucoma, Benign Prostatic Hypertrophy, Bladder Outflow Obstruction, Chronic Idiopathic Constipation, Gastrointestinal Obstruction, Illus, And Urinary Retention

Dose and Administration: By mouth, 4 mg every 4–6 hours max. 24 mg daily; for Children, 1–2 years 1 mg twice daily; 2–6 years 1 mg every 4–6 hours, max. 6 mg daily; 6–12 years 2 mg every 4–6 hours, max. 12 mg daily. By subcutaneous or intramuscular injection or by intravenous injection over 1 minute, 10–20 mg, repeated if required up to 4 times in 24 hours; max. 40 mg in 24 hours; child 1 month–1 year 250 micrograms/kg, repeated if required up to 4 times in 24 hours; 1–12 years 200 micrograms/kg or 1–6 years 2.5–5 mg, repeated if required up to 4 times in 24 hours; 6–12 years 5–10 mg, repeated if required up to 4 times in 24 hours

CYPROHEPTADINE HYDROCHLORIDE:

Indications: Allergic Conjunctivitis, Allergic Rhinitis, Dermatographic Urticaria, Nasal Congestion, and Pruritus of Skin, Rhinorrhea, Sneezing, and Urticaria

Contraindications: Acute Asthma Attack, Lactating Mother, Benign Prostatic Hypertrophy, Bladder Outflow Obstruction, Chronic Idiopathic Constipation, Glaucoma, Stenosing Peptic Ulcer, And Urinary Retention

Dose and Administration: Allergy, usual dose 4 mg 3–4 time’s daily; usual range 4–20 mg daily maxes. 32 mg daily; infant under 2 years not recommended, child 2–6 years 2 mg 2–3 times daily, max. 12 mg daily; 7–14 years 4 mg 2–3 times daily, max. 16 mg daily. Migraine, 4 mg with a further 4 mg after 30 minutes if necessary; maintenance, 4 mg every 4–6 hours

DIMETHINDENE MALEATE:

Indications: indicated as symptomatic treatment of allergic reactions: urticaria, allergies of the upper respiratory tract such as hey fever and perennial rhinitis, food and drug allergies; pruritus of various origins, also indicated for pruritus in eruptive skin diseases such as chicken pox.

Contraindications: When the patient is hypersensitive to the active substance

Dose and Administration: Average daily dosage (in three doses spread over the day)

KETOTIFEN:

Indications: allergic rhinitis

Contraindications: pregnancy and breast-feeding

Dose and Administration:

1 mg twice daily with food increased if necessary to

2 mg twice daily; initial treatment in readily sedated patients 0.5–1 mg at night;

child 3 years and over, 1 mg twice daily

PROMETHAZINE HYDROCHLORIDE:

Indications: symptomatic relief of allergy such as hay fever, urticaria; premedication; emergency treatment of anaphylactic reactions, sedation and motion sickness.

Contraindications: Coma, Lactating Mother, Agranulocytosis, Bone Marrow Depression, Chronic Idiopathic Constipation, Chronic Obstructive Pulmonary Disease, CNS Depression, Extrapyramidal Disease, Gangrene, Injection Site Sequelae, Leukopenia, Lower Seizure Threshold, Narrow Angle Glaucoma, Neuroleptic Malignant Syndrome, Respiratory Depression, Seizure Disorder, Sleep Apnea, Tissue Necrosis

Dose and Administration: By mouth, 25 mg at night increased to 25 mg twice daily if necessary or 10–20 mg 2–3 times daily; child under 2 years not recommended, 2–5 years 5–15 mg daily in 1–2 divided doses, 5–10 years 10– 25 mg daily in 1–2 divided doses. Premedication, child under 2 years not recommended, 2–5 years 15–20 mg, 5–10 years 20–25 mg. By slow intravenous injection in emergencies, 25–50 mg as a solution containing 2.5 mg/mL in water for injections; max. 100 mg.

Non-Sedating Antihistamines

LORATIDINE:

Indications: Allergic Rhinitis, Chronic Idiopathic Urticaria, Nasal Congestion, and Sneezing.

Contraindications: Disease of Liver, Hepatic Failure, Renal Disease with

Moderate to Severe Function Impairment

Dose and Administration:

adult and child over 6 years 10 mg once daily;

child2–6 years 5 mg once daily

CETIRIZINE HYDROCHLORIDE:

Indications: Allergic Rhinitis, Atopic Rhinitis, Chronic Idiopathic Urticaria, Seasonal Allergic Rhinitis, Atopic Dermatitis, and Urticaria

Contraindications: Renal Disease, Disease of Liver, Glaucoma, And Urinary Retention.

Dose and Administration: adult and child over 6 years, 10 mg once daily or 5 mg twice daily; child 2–6 years, hay fever, 5 mg once daily or 2.5 mg twice daily

DESLORATADINE:

Indications: Allergic Rhinitis, Atopic Rhinitis, Chronic Idiopathic Urticaria, And

Seasonal Allergic Rhinitis

Contraindications: Disease of Liver, Renal Disease

Dose and Administration:

Adults 5 mg once daily;

child 1–6 years 1.25 mg once daily,

6–12 years 2.5 mg once daily

LEVOCETIRIZINE HYDROCHLORIDE:

Indications: Allergic Rhinitis, Atopic Rhinitis, Chronic Idiopathic Urticaria, Seasonal Allergic Rhinitis, Atopic Dermatitis, and Urticaria

Contraindications: Chronic Renal Failure Syndrome, Hemodialysis with High-Flux Membrane

Dose and Administration: adult and child over 6 years, 5 mg once daily

FEXOFENADINE HYDROCHLORIDE:

Indications: Allergic Rhinitis, Chronic Idiopathic Urticaria, And Seasonal Allergic Rhinitis

Contraindications: Renal Disease

Dose and Administration: Seasonal allergic rhinitis, 120 mg once daily; child 6–12 years, 30 mg twice daily. Chronic idiopathic urticaria, adult and child over 12 years, 180 mg once daily