Angioedema from ACE inhibitors and related blood pressure medicines

Angioedema is swelling in the deeper layers of the skin or the lining of the mouth, throat or gut. The NHS describes the lips, tongue and eyelids as the most commonly affected areas, with the hands, feet and genitals also involved at times. If the throat swells, breathing can become difficult, which is a medical emergency.

With ACE inhibitors the swelling often builds more slowly than a typical allergic reaction, and the MHRA notes that it usually happens without hives. A person might first notice a thick-feeling tongue, a puffy lip or a change in voice. Some people have abdominal pain and cramping because the bowel wall is swollen.

• Swelling of the lips, tongue, face or throat, which may become obvious over hours rather than minutes

• Difficulty swallowing, a muffled voice or a tight throat

• Colicky tummy pain or cramps that have no other explanation

• No itchy raised rash in many cases, which can make it easy to mistake for something minor

ACE inhibitors work partly by blocking the enzyme that also breaks down bradykinin, a chemical that makes blood vessels leaky. When bradykinin builds up in susceptible people, fluid can escape into tissues and cause swelling. The MHRA separates this bradykinin-mediated form from histamine-mediated (allergic) angioedema, because the treatment strategies differ significantly.

The same drug class is also behind the persistent dry cough some people develop; the two reactions are not the same problem, but both relate to this pathway. The MHRA review of UK Yellow Card reports found that about half of the reports giving a time to onset described swelling that began 30 days or more after starting treatment. That is why the regulator has asked for product information to be strengthened on delayed-onset angioedema.

The MHRA also lists groups who may be at higher risk: older adults, women, people who smoke, and people of Black or African Caribbean ethnicity. The NHS ramipril page makes a similar point about black skin. None of this means other people are safe from it.

The NHS lists angioedema as a recognised problem with ramipril and other ACE inhibitors. For angiotensin receptor blockers such as losartan, the NHS asks people to say if they have ever had angioedema before starting, which tells you the prescriber treats a previous episode as a relevant risk. Doctors do sometimes consider an ARB for people who need the benefit of this type of medicine after an ACE inhibitor has caused problems, but that is a specialist-guided judgement made case by case, not a rule to apply yourself.

Angioedema can also come from allergic reactions to foods or other medicines, from hereditary and acquired C1-inhibitor problems, or occur for no clear reason. The MHRA points out that a clinician may still recommend an ACE inhibitor for someone whose earlier angioedema had another cause, so the full history matters.

NHS advice is to call 999 if the lips, mouth, throat or tongue suddenly swell, or if there is difficulty breathing or swallowing, and not to drive to A&E yourself. The MHRA advice to patients is to stop taking the ACE inhibitor if angioedema is suspected, tell a healthcare professional immediately, and not restart it afterwards.

In hospital, emergency teams assess and protect the airway first. The MHRA tells clinicians that a poor response to the usual anaphylaxis treatment should prompt them to consider a bradykinin cause, and that tests such as a C4 level may help identify non-allergic causes. Antihistamines and steroid tablets form part of standard angioedema care in the NHS description, but they are not guaranteed to work for this type.

Bring the packet or a list of every medicine, because other blood pressure or heart tablets may need to be reviewed at the same time.

A reaction like this should be written into the GP record and the hospital notes as a medicine reaction, with the name of the drug class rather than only the tablet you were taking. This stops a different "-pril" being prescribed by accident and gives pharmacists something to check against.

Blood pressure or heart-failure treatment still needs to continue in some form. The prescriber will discuss alternative classes and decide whether an ARB or a different type of medicine is appropriate. Bring up any family history of swelling attacks, as that can point towards hereditary angioedema, a separate condition that needs specialist care.

Anyone who has had angioedema should ask their pharmacist to flag it on their medication record, and mention it to every new prescriber, dentist and hospital team.

The Yellow Card scheme lets patients, carers and healthcare professionals report suspected side effects directly to the MHRA. The 2026 ACE inhibitor safety update was built partly from Yellow Card data, and the regulator described a phased update of the product information and patient leaflets for the whole class.

Reporting does not replace getting treatment; it is something to do once the person is safe. Details such as the medicine name, how long it was taken, when the swelling began and the outcome all help the MHRA see patterns.