Dr Sharon Rees @reesprescribe
Day 1: Technological advances allowed the development of a humanised anti-IgE monoclonal antibody (MAB) capable of neutralising immunoglobulin E (IgE) action for the management of allergic asthma and chronic urticaria. #omalizumab is 95% human and 5% murine. Licensed by the European Medicines Agency in 2005.
Dr Sharon Rees @reesprescribe
Day 2: #omalizumab is used in people ≥ 6 years old for moderate to severe IgE-mediated allergic asthma, with frequent symptoms/exacerbations despite optimum therapy and proof of one or more aeroallergen. Usually added into other therapies.
Dr Sharon Rees @reesprescribe
Day 3: #omalizumab subcutaneous injection(s) dosing is based on serum IgE levels and body weight (kg); range 75–600 mg every 2–4 weeks. UK license also for idiopathic chronic urticaria ≥12 years 300 mg once/month for 6 months.
Dr Sharon Rees @reesprescribe
Day 4:#omalizumab kinetics; subcutaneous injection gives moderate absorption (1 week to cmax) and 62% bioavailability. Breakdown is via IgE clearance processes ie recycled and degraded by liver phagocytic cells (reticuloendothelial system) and endothelial cells. T½ 24–26 days, so can take 12–16 weeks to work. Check efficacy at this point.
Dr Sharon Rees @reesprescribe
Day 5: #omalizumab blocks the IgE domain which binds to the Fc receptors on mast cells, basophils and other inflammatory cells. This lowers IgE levels, down-regulates IgE receptor expression on allergic cells and decreases mediator release; the combination of effects reduces allergic symptoms.
Dr Sharon Rees @reesprescribe
Day 6: #omalizumab common adverse drug events include headaches, abdominal pain, pruritus, arthralgia and pyrexia (children). Rare/serious: anaphylaxis, serum sickness, angioedema, systemic lupus erythematosus. There are no drug–drug interactions stated in the summary of product characteristics or British National Formulary. #omalizumab may attenuate the immunological response to helminth infections and/or treatment for helminth infections.
Dr Sharon Rees @reesprescribe
Day 7: The optimum duration for #omalizumab use is not established for asthma, but the treatment can continue if working.
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In addition to the tweets, read the BNF treatment summary on antihistamines, allergen immunotherapy and allergic emergencies, as well as the monograph on omalizumab. Another useful source is the Summary of Product Characteristics for omalizumab– see links below. Please submit the answers to reesprescribe@gmail.com as a numbered list with TRUE/FALSE or the correct A,B,C,D option. If you achieve 8 or more out of ten on the questions, a CPD certificate will be emailed to you.
- Omalizumab is an immunoglobulin found naturally in the body TRUE or FALSE?
- The half-life for omalizumab is very long, which means the drug can take months to work TRUE or FALSE?
- Omalizumab is a fully humanised monoclonal antibody TRUE or FALSE?
- Omalizumab is associated with multiple drug-drug interactions TRUE or FALSE?
- Omalizumab is designed to bind to many immunogloblulins, but its main target is IgE TRUE or FALSE?
- Which of the following is TRUE about omalizumab?
- It is licensed in the UK for use in allergic rhinitis
- It is a first-line drug for acute asthma if very severe
- It is given by intramuscular injection
- It is given by subcuteneous injection
- Dosing for omalizumab is based on age and weight TRUE or FALSE?
- Which of the following is TRUE?
- Omalizumab should not be used with anti-muscarinic inhalers
- Omalizumab down-regulates the allergic cascade
- The drug works rapidly after giving the injection
- Omalizumab is known to be safe in pregnancy
- People with asthma can come off all their other asthma medications once they start omalizumab TRUE or FALSE?
- Which pair are common adverse drug events for omalizumab?
- Alopecia and cough
- Systemic lupus erythematosus and myalgia
- Hypersensitive reactions and weight gain
- Headache and skin reactions