Zestril Side Effects: What to Expect and When to Call Your Doctor

Zestril (lisinopril) is generally well tolerated, and most people take it for years without major problems. But like all medications, it can cause side effects. Knowing what to expect — and which symptoms require immediate medical attention — is an important part of taking Zestril safely.

Common Side Effects of Zestril (Lisinopril)

Most people taking lisinopril experience few side effects. The most common ones include:

• Dry, persistent cough: The most well-known ACE inhibitor side effect. It's caused by accumulation of bradykinin in the lungs and affects approximately 10-20% of patients. The cough typically starts within the first few weeks of treatment and doesn't go away on its own as long as you're taking the medication.
• Dizziness or lightheadedness: Especially common when first starting the medication or when your dose is increased. Usually improves as your body adjusts.
• Headache: Common early in treatment, usually mild and self-limiting.
• Fatigue: Some patients report feeling tired, particularly early in treatment.
• Elevated potassium (hyperkalemia): Lisinopril can raise blood potassium levels. This is usually mild and monitored with blood tests, but can become dangerous if levels rise too high.
• Nausea: Usually mild and often resolves with continued use. Taking lisinopril with food may help.

The Lisinopril Cough: What You Should Know

The dry cough associated with ACE inhibitors like lisinopril is the most common reason patients stop taking the medication. Important facts about the lisinopril cough:

• It is a class effect — all ACE inhibitors can cause it
• It is not dangerous, but can be bothersome
• It typically resolves within 1-4 weeks after stopping the medication
• If the cough is intolerable, your doctor can switch you to an ARB (like losartan or valsartan), which works similarly but does not cause this side effect

Serious Side Effects: Call Your Doctor Right Away

While rare, these side effects require immediate medical attention:

• Angioedema (EMERGENCY — call 911): Rapid, severe swelling of the face, lips, tongue, throat, hands, or feet. This is a rare but life-threatening reaction. If your tongue or throat swells, call 911 immediately — airway obstruction can occur rapidly.
• Severe hypotension (very low blood pressure): Fainting, extreme dizziness, blurred vision, or feeling like you might pass out — especially in heart failure patients or those who are dehydrated.
• Kidney problems: Decreased urine output, swelling of ankles/feet/hands, unusual fatigue. These may indicate acute kidney injury.
• Hyperkalemia (high potassium): Muscle weakness, numbness or tingling, slow or irregular heartbeat, and overall weakness. High potassium can cause dangerous heart rhythm problems.
• Liver injury (rare): Yellow skin or eyes (jaundice), right upper abdominal pain, dark urine, unusual fatigue.
• Signs of infection: Fever, chills, sore throat — rarely, lisinopril can suppress white blood cells (neutropenia/agranulocytosis).

The Black Box Warning: Fetal Toxicity

Zestril (lisinopril) carries a Black Box Warning — the FDA's most serious drug warning — for fetal toxicity. Lisinopril can cause serious injury or death to a developing baby when taken during the second or third trimester of pregnancy. If you are pregnant or become pregnant while taking Zestril, stop the medication immediately and call your doctor. Do not take Zestril if you are planning to become pregnant without discussing it with your healthcare provider first.

38,004+ patients found their medications in stock

38K+

Find Zestril In Stock Today →

Monitoring Tests While on Zestril

Your doctor will typically monitor:

• Blood pressure at each visit
• Serum creatinine and BUN (kidney function) — typically 2-4 weeks after starting and periodically thereafter
• Serum potassium — elevated potassium is a known risk, especially in patients with kidney disease or diabetes

Managing Side Effects

Most side effects can be managed by adjusting the dose, timing of medication, or dietary changes (such as limiting high-potassium foods). Never adjust your lisinopril dose or stop taking it without talking to your doctor. For more on what to avoid while taking Zestril, see our guide on Zestril drug interactions.