What Lisinopril Does

Lisinopril blocks ACE (angiotensin-converting enzyme), which normally causes blood vessels to constrict. By blocking ACE, blood vessels relax, blood pressure falls, and the heart and kidneys are protected from pressure damage.

Condition	Typical Dose	Goal
Hypertension	5–40 mg once daily	BP <130/80 mmHg
Heart failure	2.5–35 mg once daily	Reduce symptoms, hospitalisation
Diabetic kidney disease	10–20 mg once daily	Reduce protein leak (ACR)
Post heart attack	5–10 mg once daily	Reduce mortality

The ACE CoughBetween roughly 5% and 20% of people develop a persistent dry tickly cough on an ACE inhibitor, with higher rates reported in women and in some populations. This is a class effect: not an allergy. If it's troublesome, you can switch to an ARB (e.g. losartan) which works the same way without the cough.

Blood Tests to Monitor

Test	Timing	Why
Potassium	1–2 weeks after starting / dose change	ACE inhibitors raise potassium
Creatinine / eGFR	1–2 weeks after starting	A rise of <30% is acceptable
Blood pressure	1–4 weeks after each change	Ensure BP at target
Urine ACR	Annually in diabetics	Monitor kidney protein leak

First-Dose WarningThe first dose of lisinopril can cause a significant drop in blood pressure, especially if you are dehydrated or on diuretics. Take the first dose at night and get up slowly in the morning.

The Cough, and Why It Is Not an Infection

A dry, tickling cough is the most common reason people stop taking lisinopril. It is not a chest infection and not an allergy. ACE does two jobs: it makes angiotensin II, which raises blood pressure, and it breaks down bradykinin. Blocking the enzyme achieves the first and unavoidably causes the second, so bradykinin accumulates and irritates the airway.

Two things about it surprise people. It can begin weeks or months after starting, so the connection is easily missed and antibiotics are often tried first. And it does not respond to cough medicines, because nothing is wrong with the airway other than the bradykinin. It settles after the drug is stopped, though it can take weeks. There is a straightforward alternative — an angiotensin receptor blocker lowers blood pressure by a different step and does not raise bradykinin — so persisting with a cough that is spoiling your sleep is rarely necessary.

Angioedema: Rare, Not Allergic, and an Emergency

Swelling of the face, lips, tongue or throat affects roughly 0.1–0.7% of people taking an ACE inhibitor.² It is uncommon, but it is the reason this drug class carries a warning, and there are three things worth knowing in advance.

It is not an allergic reaction, and allergy treatment does not workThe swelling is caused by bradykinin building up, not by histamine. Antihistamines and corticosteroids — the standard treatment for an allergic reaction — have not been shown to be effective for it.² Swelling of the tongue or throat, or any difficulty breathing or swallowing, is an emergency: call your local emergency number. Do not wait to see whether an antihistamine helps.

Second, it can appear at any time. People assume a drug reaction happens in the first days, but ACE inhibitor angioedema can begin after months or years of uneventful treatment. A long uneventful period does not rule it out. Episodes typically last two to three days and usually need hospital care.²

Third, risk is not equal. There is a clear ethnic predisposition, with higher prevalence in people of African and Hispanic descent than in white populations, which appears to have a genetic basis in how bradykinin is metabolised.² There is no blood test that diagnoses it; the diagnosis is made from the clinical picture.³

If it happens, the ACE inhibitor is stopped permanently. Switching to an angiotensin receptor blocker is possible and is often done: some individuals do have a further episode, but large studies have not found ARBs to raise the overall risk of angioedema compared with other blood pressure drugs.² That decision belongs with your doctor, not with a page.

What to Avoid on Lisinopril

NSAIDs (ibuprofen, naproxen): raise blood pressure and potassium
Potassium supplements or potassium-sparing diuretics: dangerous hyperkalaemia
Salt substitutes: most contain high potassium
Pregnancy: ACE inhibitors are teratogenic (harm the baby)
Combined with another ACE inhibitor or ARB

Can I take ibuprofen with lisinopril?

Generally no. NSAIDs block the blood pressure lowering effect of lisinopril and can cause dangerous rises in potassium and kidney damage. Use paracetamol instead.

My creatinine rose after starting lisinopril: should I stop?

A rise of up to 30% in creatinine is expected and acceptable: it reflects reduced intraglomerular pressure, which is the protective mechanism. Stop only if it rises >30% or potassium >5.5 mmol/L.

Does lisinopril protect kidneys in diabetes?

Yes. It reduces the pressure within kidney filters (glomeruli) and decreases protein leakage in the urine. It's recommended for all diabetics with any signs of kidney involvement.

References

The clinical information on this page is based on peer-reviewed sources indexed in PubMed, the biomedical literature database of the US National Library of Medicine.

Yılmaz İ. Angiotensin-converting enzyme inhibitors induce cough. Turk Thorac J. 2019;20(1):36-42. doi:10.5152/TurkThoracJ.2018.18014 · PMID 30664426
Montinaro V, Cicardi M. ACE inhibitor-mediated angioedema. Int Immunopharmacol. 2020;78:106081. PMID 31835086 · doi:10.1016/j.intimp.2019.106081
Baram M, Kommuri A, Sellers SA, Cohn JR. ACE inhibitor-induced angioedema. J Allergy Clin Immunol Pract. 2013;1(5):442–5. PMID 24565614 · doi:10.1016/j.jaip.2013.07.005

Lisinopril: ACE Inhibitor Patient Guide