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Drug allergy and anaphylaxis
Allergy status
Distinguishing allergic reactions
Cross reacting drugs
Risk factors
Treatment
Patient follow up
Investigations
Allergy status
You should take a full allergy history before prescribing any medications. It can be
obtained from:
Patient Care home
Carer Medical notes
GP Summary care records
Community pharmacist
When taking an allergy history you
should confirm and document:
All current and any recent drugs
(OTC drugs, herbal drugs and any
injections.)
The generic name for the drug
suspected to cause a reaction
The exact signs, symptoms and the
severity of the allergic reaction
When the reaction occured
Drug allergy and anaphylaxis 1
, How long the drug was taken before
the reaction occured
Whether the allergy is a first hand
recollection
Before prescribing for a patient check:
The drug allergy box on the drug chart or electronic system
Red drug allergy band
Medical notes for documented allergies
If re-writing drug chart ensure to transcribe allergy status
Document allergy status in medical notes, discharge prescriptions, discharge letters
and primary care referral information.
Distinguishing allergic reactions
Type 1 allergic reactions occur within
minutes to 2 hours of exposure to the
triggering drug. It may not always occur
with the first dose of the drug given.
Symptoms can occur very rapidly with
parenteral drug, the median time to
cardiac arrest in fatal drug induced
anaphylaxis is 5 minutes.
Symptoms include:
Urticaria (can arise due to infection
so determine whether it started
before or after drug)
Itching
Hypotension
Angioedema (ACE-inhibitors can
cause pure angioedema, can result
Drug allergy and anaphylaxis 2
Drug allergy and anaphylaxis
Allergy status
Distinguishing allergic reactions
Cross reacting drugs
Risk factors
Treatment
Patient follow up
Investigations
Allergy status
You should take a full allergy history before prescribing any medications. It can be
obtained from:
Patient Care home
Carer Medical notes
GP Summary care records
Community pharmacist
When taking an allergy history you
should confirm and document:
All current and any recent drugs
(OTC drugs, herbal drugs and any
injections.)
The generic name for the drug
suspected to cause a reaction
The exact signs, symptoms and the
severity of the allergic reaction
When the reaction occured
Drug allergy and anaphylaxis 1
, How long the drug was taken before
the reaction occured
Whether the allergy is a first hand
recollection
Before prescribing for a patient check:
The drug allergy box on the drug chart or electronic system
Red drug allergy band
Medical notes for documented allergies
If re-writing drug chart ensure to transcribe allergy status
Document allergy status in medical notes, discharge prescriptions, discharge letters
and primary care referral information.
Distinguishing allergic reactions
Type 1 allergic reactions occur within
minutes to 2 hours of exposure to the
triggering drug. It may not always occur
with the first dose of the drug given.
Symptoms can occur very rapidly with
parenteral drug, the median time to
cardiac arrest in fatal drug induced
anaphylaxis is 5 minutes.
Symptoms include:
Urticaria (can arise due to infection
so determine whether it started
before or after drug)
Itching
Hypotension
Angioedema (ACE-inhibitors can
cause pure angioedema, can result
Drug allergy and anaphylaxis 2
