3.4.1 Antihistamines

Many of these products are cheap to buy and are readily available, along with advice, from pharmacies. Some self-care medicines are available in shops and supermarkets. Please click here for further information and a patient leaflet

Cetirizine
  • Tablets 10mg (£0.77)
  • Oral solution 5mg/5ml (£1.52 = 200ml)

Indications

Dose

  • Adult and child over 12 years, 10mg once daily;
  • Child, 2–6 years 2.5mg twice daily, 6–12 years 5mg twice daily
Chlorphenamine
  • Tablets 4mg (£3.04 = 4mg six hourly)
  • Liquid 2mg/5ml (£2.62 = 150ml)
  • Injection 10mg/ml (£4.50 = 1ml amp)

Indications

Dose

  • Oral, 4mg every 4–6 hours, maximum 24mg daily (elderly maximum 12mg daily);
  • Oral, child 1–2 years 1mg twice daily; 2–6 years 1mg every 4–6 hours, maximum 6mg daily; 6–12 years 2mg every 4–6 hours, maximum 12mg daily
  • I/M or I/V over 1 minute, 10mg, repeated if required up to maximum 4 doses in 24 hours; child under 6 months 250 micrograms/kg (maximum 2.5mg); 6 months–6 years 2.5mg; 6–12 years 5mg; these doses may be repeated if required up to maximum 4 doses in 24 hours
Loratadine
  • Tablets 10mg (£0.81)
  • Syrup 5mg/5ml (£1.89 = 100ml)

Indications

Dose

  • Adult and child over 12 years 10mg once daily;
  • Child 2–12 years, body-weight under 30 kg, 5mg once daily; body-weight over 30 kg, 10mg once daily
Hydroxyzine
  • Tablets 10mg, 25mg (£0.62 = 28 x 25mg)

Indications

Notes

  1. MHRA Drug Safety Update (April 2015):
    1. do not prescribe hydroxyzine to people with a prolonged QT interval or who have risk factors for QT interval prolongation
    2. avoid use in the elderly - they are more susceptible than younger patients to the side effects of hydroxyzine
    3. consider the risks of QT interval prolongation and Torsade de Pointes before prescribing to patients taking medicines that lower heart rate or potassium levels
    4. the maximum daily dose is now
      1. 100mg for adults
      2. 50mg for the elderly (if use cannot be avoided)
      3. 2mg per kg body weight for children up to 40kg in weight
    5. prescribe the lowest effective dose for as short a time as possible
Promethazine hydrochloride
  • Tablets 10mg, 25mg (£4.65 = 56 x 25mg)

Indications

Dose

  • Insomnia: 25-50mg at night
  • Nausea and vomiting in pregnancy and Hyperemesis Gravidarum: Initially 25mg at night; can be increased to 25mg morning and evening

Notes

  1. Promethazine may be a useful alternative to benzodiazepines and other hypnotics for night time sedation, also where possible benzodiazepine dependence is a major concern. However, residual sedation may occur the following day and its sedative effects may diminish after a few days of continued treatment.
Fexofenadine
  • Tablets 180mg (£2.73)

Indication

  • For the treatment of chronic idiopathic urticaria in patients not adequately treated with cetirizine.

Dose

  • Chronic idiopathic urticaria, adult and child over 12 years, 180mg once daily

Notes

  1. Fexofenadine 180mg is only included in the formulary for chronic idiopathic urticaria.
  2. The 120mg tablets are not included in the formulary

 

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