Antihistamines, Allergen Immunotherapy And Allergic Emergencies

Question 1

All ________________ are of potential value in the treatment of nasal allergies, particularly seasonal allergic rhinitis (hayfever), and they may be of some value in vasomotor rhinitis

Answer 1

antihistamines

Question 2

All antihistamines are of potential value in the treatment of nasal ______________, particularly ______________ rhinitis, and they may be of some value in ______________ rhinitis

Answer 2

nasal allergies

seasonal allergic (hayfever)

vasomotor

Question 3

Antihistamines reduce ______________ and ________________ but are usually less effective for ________________

Answer 3

rhinorrhoea

sneezing

nasal congestion

Question 4

Antihistamines are used ________________ in the eye, in the nose, and on the skin

Answer 4

topically

Question 5

Oral antihistamines are also of some value in preventing ____________ and are used to treat ______________ rashes, ____________, and __________; they are also used in drug allergies

Answer 5

urticaria

urticarial

pruritus

insect bites and stings

Question 6

Antihistamines may also be given in ______________ following initial stabilisation of the patient, especially in patients with persistent cutaneous symptoms

Answer 6

anaphylaxis

Question 7

Antihistamines may also be given in anaphylaxis following initial stabilisation of the patient, especially in patients with persistent _____________ symptoms

Answer 7

cutaneous

Question 8

Antihistamines (including cinnarizine, cyclizine, and promethazine teoclate) may also have a role in ________________ and _______________

Answer 8

nausea

vomiting

Question 9

Buclizine is included as an anti-emetic in a preparation for _____________

Answer 9

migraine

Question 10

Buclizine is included as an ________________ in a preparation for migraine

Answer 10

anti-emetic

Question 11

Antihistamines may also have a role in occasional _____________

Answer 11

insomnia

Question 12

All older antihistamines cause sedation but ________________ and ________________ may be more sedating whereas chlorphenamine maleate and cyclizine may be less so

Answer 12

alimemazine tartrate

promethazine

Question 13

All older antihistamines cause sedation but alimemazine tartrate and promethazine may be more sedating whereas _______________ and _________________ may be less so

Answer 13

chlorphenamine

cyclizine

Question 14

Non-sedating antihistamines such as acrivastine, bilastine, cetirizine hydrochloride, desloratadine (an active metabolite of loratadine), fexofenadine hydrochloride (an active metabolite of terfenadine), levocetirizine hydrochloride (an isomer of cetirizine hydrochloride), loratadine and mizolastine cause less sedation and psychomotor impairment than the older antihistamines because they ___________________

Answer 14

penetrate the blood brain barrier only to a slight extent

Question 15

The use of first-generation antihistamines in _____________ patients is potentially inappropriate (STOPP criteria) as safer, less toxic antihistamines are widely available

Answer 15

elderly

Question 16

The use of ________________ antihistamines in elderly patients is potentially inappropriate (STOPP criteria) as safer, less toxic antihistamines are widely available

Answer 16

first-generation

Question 17

What are the second generation antihistamines? (3)

Answer 17

1. Cetirizine
2. Fexofenadine
3. Loratadine

• the fox, the satyr, and the rat

Question 18

What are the main first generation antihistamines? (5)

Answer 18

1. Diphenhydramine
2. Carbinoxamine
3. Clemastine
4. Chlorpheniramine
5. Brompheniramine

Question 19

Immunotherapy using ____________________ containing house dust mite, animal dander (cat or dog), or grass pollen extract and tree pollen extract can reduce symptoms of asthma and allergic rhinoconjunctivitis

Answer 19

allergen vaccines

Question 20

Immunotherapy using allergen vaccines containing house dust mite, animal dander (cat or dog), or grass pollen extract and tree pollen extract can reduce symptoms of ______________ and allergic __________________

Answer 20

asthma

rhinoconjunctivitis

Question 21

Vaccines containing wasp venom extract or bee venom extract may be used to reduce the risk of severe ______________ and systemic reactions in individuals with hypersensitivity to wasp and bee stings.

Answer 21

anaphylaxis

Question 22

An ____________ preparation of grass pollen extract is licensed for disease-modifying treatment of grass pollen-induced rhinitis and conjunctivitis, and an ____________ preparation of house dust mite extract is licensed for disease-modifying treatment of house dust mite allergic rhinitis or asthma in certain patients

Answer 22

oral

oral

Question 23

______________ is a monoclonal antibody that binds to immunoglobulin E (IgE). It is used as additional therapy in individuals with proven IgE-mediated sensitivity to inhaled allergens, whose severe persistent allergic asthma cannot be controlled adequately with high dose inhaled corticosteroid together with a long-acting beta2 agonist

Answer 23

Omalizumab

Question 24

What is anaphylaxis?

Answer 24

a severe, life-threatening, generalised or systemic hypersensitivity reaction

Question 25

Anaphylaxis is characterised by rapidly developing _____________ and/or ______________ and/or ______________ problems, and is usually associated with skin and mucosal changes; prompt treatment is required.

Answer 25

airway breathing circulation

Question 26

What are the most common allergens that cause anaphylaxis? (4)

Answer 26

1. Food (e.g. peanuts, sesame, tree nuts, soy, shellfish, and cow's milk) 2. Drugs (e.g. antibacterials, aspirin and other NSAIDs, neuromuscular blocking drugs, chlorhexidine, contrast media, and vaccines) 3. Venom (e.g. insect stings) 4. Latex

Question 27

In the case of drugs, anaphylaxis is more likely after _____________ administration

Answer 27

parenteral

Question 28

Anaphylactic reactions may also be associated with ____________ and ____________ in foods and medicines

Answer 28

additives excipients

Question 29

Is refined arachis (peanut) oil present in some medical products likely to cause an allergic reaction?

Answer 29

Unlikely — nevertheless it is wise to check the full formula of preparations which may contain allergens

Question 30

Certain patients may be at higher risk of anaphylaxis, either because of ________________ or because of _________________

Answer 30

an existing comorbidity (such as asthma) an increased likelihood of repeated exposure to the same allergen (such as those with venom or food allergies)

Question 31

_________________ may follow an anaphylactic reaction

Answer 31

Cardiopulmonary arrest; start cardiopulmonary resuscitation (CPR) immediately

Question 32

What is the immediate management of anaphylaxis? (10)

Answer 32

1. Immediately call for an ambulance or the resuscitation team 2. Remove the trigger if possible (eg drug or insect stinger) 3. Place patient in a comfortable (eg flat to aid in the restoration of blood pressure OR semi-recumbent if airway or breathing problems and no evidence of CV instability OR in the recovery position for unconscious patients who are breathing normally) 4. IM adrenaline 5. Assess response to treatment by monitoring vitals and auscultate for wheeze 6. Repeat dose of IM adrenaline given after 5-min if there is no improvement in the patient’s condition 7. Nebulized adrenaline may be added as an adjunct to treat upper airway obstruction (but only after treatment with IM adrenaline and NOT as an alternative) 8. High flow O2 given as soon as it is available 9. IV fluids for patients with which or if there is poor response to initial dose of adrenaline 10. Inhaled bronchodilator therapy may also be considered for patients with persistent respiratory problems but should NOT be used as an alternative to further treatment with adrenaline *antihistamines are NOT part of the initial emergency treatment of anaphylaxis but may be used following stabilization in patients with persistent cutaneous symptoms (same with oral steroids)

Question 33

What is the dose of adrenaline used to treat anaphylaxis in adults?

Answer 33

IM 500 micrograms of adrenaline 1 in 1000 *same for children 12-17 yo

Question 34

What is the dose of adrenaline used to treat anaphylaxis in children under 12 yo?

Answer 34

6-11 yo: 300 micrograms adrenaline 1 in 1000 6 mo-5 yo: 150 micrograms adrenaline 1 in 1000 Up to 6 mo: 100-150

Question 35

What is the dilution of adrenaline used in CPR vs anaphylaxis?

Answer 35

CPR: 1 in 10,000 or 100 micrograms/mL (1 mg for adults) Anaphylaxis: 1 in 1,000 or 1 mg/mL (500 micrograms for adults)

Question 36

Patients who have no improvement in respiratory and/or cardiovascular problems despite _______ appropriate doses of intramuscular adrenaline/epinephrine, should have their care escalated quickly and managed as having refractory anaphylaxis

Answer 36

2

Question 37

Nebulised adrenaline/epinephrine may be effective as an adjunct to treat upper airways obstruction caused by laryngeal oedema, but only after treatment with _______________ and not as an alternative

Answer 37

intramuscular adrenaline/epinephrine

Question 38

Antihistamines _________ (are/are not) recommended as part of the initial emergency treatment of anaphylaxis

Answer 38

Are not; may be used following stabilization, especially in patients with persistent cutaneous symptoms

Question 39

The routine use of corticosteroids for the emergency treatment of anaphylaxis ______ (is/is not) recommended

Answer 39

Is not; may be used after initial resuscitation for refractory reactions or ongoing asthma/shock

Question 40

Can corticosteroids be given instead of adrenaline in the initial treatment of anaphylaxis?

Answer 40

Nooope; only after initial resuscitation with adrenaline for refractory reactions or ongoing asthma/shock Oral route where possible

Question 41

Refractory anaphylaxis is defined as anaphylaxis that requires ongoing treatment due to persisting respiratory and/or cardiovascular problems despite ____ appropriate doses of intramuscular adrenaline/epinephrine

Answer 41

2

Question 42

Adrenaline/epinephrine therapy should be supported with ____________ therapy

Answer 42

intravenous fluid

Question 43

Patients should be treated with an intravenous adrenaline/epinephrine infusion. Intravenous adrenaline/epinephrine should only be given by experienced specialists and in a setting where patients can be carefully monitored. If an intravenous infusion cannot be administered safely (e.g. due to a patient being outside a hospital setting), __________________

Answer 43

continue to give intramuscular adrenaline/epinephrine at 5-minute intervals while life-threatening cardiovascular and/or respiratory features persist

Question 44

If pregnant, what position should patients be put in during an episode of anaphylaxis?

Answer 44

Lie on left side to prevent aortic compression

Question 45

Where should IM adrenaline be given?

Answer 45

Anterolateral aspect — middle third of thigh

Question 46

What are the signs of life-threatening airway problems? (2)

Answer 46

1. Hoarse voice | 2. Stridor

Question 47

What are the signs of life-threatening breathing problems? (5)

Answer 47

1. Increased work of breathing 2. Wheeze 3. Fatigue 4. Cyanosis 5. SpO2<94%

Question 48

What are the signs of life-threatening circulation problems? (4)

Answer 48

1. Low BP 2. Signs of shock 3. Confusion 4. Reduced consciousness

Question 49

What volume of fluids should be given to adults in the treatment of anaphylaxis following IM adrenaline administration?

Answer 49

IV fluid challenge with crystalloid — 500-1000 mL (10 mL/kg in children) https://www.resus.org.uk/sites/default/files/2021-04/Anaphylaxis%20algorithm%202021.pdf

Question 50

How should patients be managed prior to discharge following an episode of anaphylaxis? (3)

Answer 50

1. Provided with 2 adrenaline auto-injectors 2. Trained on their correct use 3. Advised to carry them at all times

Question 51

The provision of adrenaline/epinephrine auto-injectors are appropriate for all patients who have had anaphylaxis, with the exception of those with a _____________

Answer 51

drug-induced reaction (unless future exposure to the trigger drug will be difficult to avoid)

Question 52

______________ can be caused by an allergic reaction. It involves the swelling of deeper tissues, most commonly in the eyelids and lips, and sometimes the tongue and throat

Answer 52

Angioedema

Question 53

Allergic angioedema that occurs with life-threatening airway and/or breathing and/or circulatory problems should be managed as _______________

Answer 53

anaphylaxis

Question 54

Unlike allergic angioedema, adrenaline/epinephrine, corticosteroids, and antihistamines should not be used for the treatment of acute attacks of ______________________

Answer 54

Hereditary angioedema (including attacks involving laryngeal oedema) as they are ineffective and may delay appropriate treatment—intubation may be necessary *C1-esterase inhibitors should be used instead

Question 55

What is the treatment of choice for acute hereditary angioedema?

Answer 55

C1-esterase inhibitors, an endogenous complement blocker derived from human plasma

Question 56

Which drugs can be used for short-term prophylaxis of hereditary angioedema? (2)

Answer 56

1. Tranexamic acid 2. Danazol (unlicensed) *started several days before planned procedures (eg dental work) and continued for 2-5 days afterwards

Question 57

Non-sedating antihistamines such as certirizine hydrochloride cause less ____________ and ______________ impairment than the older antihistamines, but can still occur; sedation is generally minimal

Answer 57

sedation psychomotor

Question 58

Children under _______ years should not be given over-the-counter cough and cold medicines containing chlorphenamine

Answer 58

6

Question 59

Children under 6 years should not be given over-the-counter cough and cold medicines containing ____________

Answer 59

chlorphenamine (a 1st gen antihistamine)

Question 60

Older antihistamines should be prescribed with caution in patients with which conditions? (5)

Answer 60

1. Epilepsy 2. Prostatic hypertrophy 3. Pyloroduodenal obstruction 4. Susceptibility to angle-closure glaucoma 5. Urinary retention (Due to anti-cholinergic effects)

Question 61

What are the common side effects of first generation antihistamines? (8)

Answer 61

1. Impaired concentration 2. Abnormal coordination 3. Dizziness 4. Dry mouth 5. Fatigue 6. Headache 7. Nausea 8. Blurred vision (Due to anti-cholinergic effects)

Question 62

What advice should be given to patients and carers regarding antihistamines?

Answer 62

Drowsiness may affect performance of skilled tasks eg cycling or driving Sedating effects are enhanced by alcohol

Question 63

Sedating effects of antihistamines are enhanced by consumption of ___________

Answer 63

Alcohol

Question 64

Adrenaline is not licensed for the treatment of CPR in ____________ and infants with body-weight under ____________

Answer 64

Infants 5 kg (But still used in this group)

Question 65

Adrenaline should be prescribed with caution in which patients? (20)

Answer 65

1. Arteriosclerosis 2. Arrhythmias 3. Cerebrovascular disease 4. Cor pulmonale 5. DM 6. Elderly 7. Hypercalcemia 8. Hyperreflexia 9. HTN 10. Hyperthyroidism 11. Hypokalemia 12. IHD 13. Obstructive cardiomyopathy 14. Occlusive vascular disease 15. Organic brain damage 16. Pheochromocytoma 17. Prostate disorders 18. Psychoneurosis 19. Severe angina 20. Susceptibility to angle closure glaucoma **cautions are only for non-life-threatening situations

Question 66

What is the main side effect of adrenaline?

Answer 66

Cardiomyopathy and MI but also may cause injection site necrosis, CNS hemorrhage, hepatic/renal/ intestinal necrosis, pulmonary edema

Question 67

IM use of adrenaline in pregnancy may reduce ___________ and cause ___________, ___________, and ___________ in fetus. Can delay second stage of labor

Answer 67

placental perfusion tachycardia cardiac irregularities extrasystoles **only use if benefits outweigh risk

Question 68

Is adrenaline safe to administer while breastfeeding?

Answer 68

Yes; present in milk but poor oral bioavailability so unlikely to cause harm

Question 69

What monitoring is required when administering adrenaline?

Answer 69

Monitor BP and ECG

Question 70

Which antihistamines are used in the management of nausea and vomiting? (4)

Answer 70

1. Cyclizine 2. Cinnarizine 3. Promethazine 4. Buclizine