Lisinopril: Answers to the Most Frequently Asked Questions

What Is Lisinopril Used For?

Lisinopril is an ACE inhibitor (angiotensin-converting enzyme inhibitor) FDA-approved for three main conditions:

1. Hypertension (high blood pressure) — [lisinopril](/drugs/lisinopril) is one of the most commonly prescribed blood pressure medications in the US.
2. Heart failure — lisinopril reduces hospitalizations and mortality in patients with [heart failure](/conditions/heart-failure) with reduced ejection fraction.
3. Post-myocardial infarction (heart attack) — started within 24 hours of a heart attack to protect the heart muscle and reduce mortality.

Lisinopril is also used off-label for diabetic kidney disease (nephropathy) to slow progression to kidney failure.

How Does Lisinopril Lower Blood Pressure?

Lisinopril blocks the angiotensin-converting enzyme (ACE), which normally converts angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor — it narrows blood vessels and signals the kidneys to retain sodium and water, both of which raise blood pressure. By blocking ACE, lisinopril reduces angiotensin II levels, causing blood vessels to relax (vasodilation) and the kidneys to excrete more sodium and water, lowering blood pressure.

How Long Does Lisinopril Take to Work?

Lisinopril begins lowering blood pressure within 1–2 hours of the first dose, with peak effect at 6–8 hours. However, the full antihypertensive effect may take 2–4 weeks of consistent daily dosing to manifest. If your blood pressure is not at goal after 2–4 weeks, your doctor may increase the dose or add another medication.

What Are the Most Common Side Effects of Lisinopril?

The most common side effect is a persistent, dry cough that affects 10–15% of patients (up to 40% in Asian patients). This is a class effect of all [ACE inhibitors](/drug-classes/ace-inhibitors) caused by bradykinin accumulation in the lungs. If the cough is bothersome, switching to an ARB (such as [losartan](/drugs/losartan)) eliminates it.

Other common side effects include:

• Dizziness, especially when standing up quickly (orthostatic hypotension) — more common when starting or increasing the dose
• Elevated potassium (hyperkalemia) — monitor potassium levels, especially if also taking potassium supplements or potassium-sparing diuretics
• Elevated creatinine — a small rise in creatinine is expected and usually not concerning; a rise >30% from baseline warrants evaluation

A rare but serious side effect is angioedema — sudden swelling of the face, lips, tongue, or throat. This is a medical emergency. Stop lisinopril immediately and seek emergency care if this occurs.

What Foods and Drugs Interact with Lisinopril?

Foods: High-potassium foods (bananas, oranges, potatoes, tomatoes, spinach) can raise potassium levels when combined with lisinopril, especially in patients with kidney disease. Salt substitutes often contain potassium chloride — avoid these while taking lisinopril.

Drugs:

• NSAIDs (ibuprofen, naproxen): Reduce lisinopril's effectiveness and increase kidney injury risk — avoid regular use
• Potassium supplements or potassium-sparing diuretics (spironolactone, triamterene): Increase hyperkalemia risk
• Lithium: Lisinopril can increase lithium levels to toxic ranges
• [ARBs](/drug-classes/arbs) or aliskiren: Dual RAAS blockade increases hyperkalemia and kidney injury risk — avoid combining

What Happens If I Miss a Dose?

Take the missed dose as soon as you remember, unless it is almost time for your next dose — in that case, skip the missed dose and continue your regular schedule. Do not double up. Missing an occasional dose will not cause immediate harm, but consistent missed doses will reduce blood pressure control.

Can I Stop Taking Lisinopril Suddenly?

Unlike [beta-blockers](/drug-classes/beta-blockers), lisinopril does not need to be tapered — it can be stopped abruptly if necessary. However, stopping lisinopril will cause blood pressure to rise again, which can increase the risk of stroke and heart attack. Do not stop lisinopril without talking to your doctor first, who can prescribe an alternative if needed.

Is Lisinopril Safe During Pregnancy?

No. Lisinopril is contraindicated in pregnancy (FDA Category D/X). ACE inhibitors can cause fetal kidney damage, oligohydramnios (low amniotic fluid), limb contractures, and death when used in the second and third trimesters. If you become pregnant while taking lisinopril, stop it immediately and contact your doctor. Safe alternatives for blood pressure control in pregnancy include labetalol, nifedipine, and methyldopa.

How Much Does Lisinopril Cost Without Insurance?

Lisinopril is one of the least expensive medications available. Generic lisinopril typically costs $4–$10 for a 30-day supply at most pharmacies using GoodRx or RxGo coupons. Walmart's $4 prescription program includes lisinopril. A 90-day supply is often available for $10–$15.

References

1. Whelton PK, et al. 2017 ACC/AHA Guideline for High Blood Pressure. J Am Coll Cardiol. 2018;71(19):e127-e248.
2. Yancy CW, et al. 2013 ACCF/AHA Guideline for the Management of Heart Failure. J Am Coll Cardiol. 2013;62(16):e147-e239.