Lisinopril is an Angiotensin-Converting Enzyme (ACE) inhibitor, commonly prescribed to manage high blood pressure and treat heart failure. This medication works to reduce strain on the heart and blood vessels. Dizziness is a frequently reported side effect associated with lisinopril use, as it lowers blood pressure.
How Lisinopril Affects Blood Pressure
Lisinopril blocks the Angiotensin-Converting Enzyme (ACE), preventing the formation of Angiotensin II, a powerful protein that narrows blood vessels. By interrupting this process, lisinopril promotes vasodilation (widening of arteries and veins). This allows blood to flow more easily and reduces pressure against the vessel walls, effectively lowering blood pressure.
The physiological reason for dizziness is often orthostatic hypotension, a sudden drop in blood pressure upon standing. When the medication dilates blood vessels, the body sometimes struggles to quickly adjust blood flow to the brain when changing position. This temporary lack of adequate blood flow to the head causes lightheadedness or dizziness.
This side effect is most likely to occur when a person first begins taking the medication or immediately following an increase in dosage. The body needs time to acclimate to the drug’s pressure-lowering effects. Patients taking diuretics, or “water pills,” may experience a heightened risk of low blood pressure and subsequent dizziness.
Reducing the Risk of Dizziness
Since dizziness is related to a rapid drop in blood pressure, simple behavioral changes can mitigate the risk. The most direct action is to rise slowly and deliberately when moving from a seated or reclined position. Before standing, sit on the edge of the bed or chair for a few moments. If lightheadedness occurs, sitting or lying down immediately helps prevent a potential fall or fainting episode.
Maintaining adequate hydration is helpful in stabilizing blood volume. Dehydration can exacerbate the pressure-lowering effect of lisinopril, increasing the likelihood of dizziness. This is particularly relevant during periods of heavy sweating, illness involving vomiting or diarrhea, or intense physical activity.
It is recommended to avoid or limit alcohol intake, especially when first adjusting to the medication. Alcohol can further widen blood vessels and intensify the drug’s hypotensive effect.
Consistent medication timing is also helpful; some healthcare providers suggest taking the initial dose at bedtime. This minimizes initial daytime dizziness by allowing the body to experience the peak pressure-lowering effect while the patient is asleep. Avoiding sudden temperature changes, such as hot baths or showers, is prudent because heat can cause further vasodilation and drop blood pressure.
Recognizing Serious Adverse Effects
While mild dizziness is a common and manageable side effect, patients must learn to distinguish it from symptoms that require urgent medical evaluation. Fainting (syncope) or persistent, severe lightheadedness that does not improve indicates that blood pressure may be too low. If fainting occurs, emergency medical help should be sought immediately.
A rare but potentially life-threatening reaction associated with lisinopril is angioedema, which involves severe swelling beneath the skin. Symptoms include swelling of the face, lips, tongue, or throat, which can quickly lead to difficulty breathing or swallowing. Any sign of facial or throat swelling requires immediate emergency intervention.
Other signs that necessitate prompt communication with a healthcare provider include chest pain, a rapid heart rate, or symptoms of hyperkalemia, such as muscle weakness or an irregular heartbeat. Lisinopril can sometimes increase potassium levels, which can be dangerous for the heart.
It is important to never suddenly stop taking lisinopril without consulting the prescribing physician, even if side effects are bothersome. Abruptly discontinuing a high blood pressure medication can lead to dangerous pressure spikes.