7 Medications That Can Cause Dangerously Low Blood Pressure

Maintaining a healthy blood pressure is vital for your overall well-being. High blood pressure (hypertension) often gets the most attention. But low blood pressure (hypotension) can also be dangerous. When your blood pressure drops too low, your vital organs may not receive enough oxygen, potentially leading to serious complications.

Hypotension has many causes, including dehydration, heart problems, and neurologic conditions like Parkinson’s disease. But medications are another common trigger, especially when taken in high doses or combined with other drugs. This can lead to symptoms such as dizziness, lightheadedness, or even fainting in more serious cases.

Below, we’ll discuss seven medications that can cause low blood pressure and share practical tips to help you manage your risk.

1. Blood pressure medications

Blood pressure medications are designed to lower your blood pressure. But sometimes they can lower it too much. This is especially the case with higher doses or if you’re taking more than one. Examples of blood pressure medications include:

• Angiotensin-converting enzyme (ACE) inhibitors like lisinopril (Zestril, Qbrelis)

• Calcium channel blockers like amlodipine (Norvasc)

• Diuretics like hydrochlorothiazide (Microzide)

• Beta blockers like metoprolol (Lopressor, Toprol XL)

• Alpha blockers like prazosin (Minipress)

It’s common to feel dizzy when starting a blood pressure medication or after your dose is increased. But persistent dizziness or low blood pressure readings at home could mean your dose is too high. Contact your healthcare team to discuss possible adjustments.

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2. Nitrates

Nitrates, such as nitroglycerin (Nitrostat, Nitromist), are used to treat and prevent chest pain. They work by widening blood vessels to improve blood flow to the heart, which can also lead to low blood pressure. To reduce the risk of dizziness or falls, it’s recommended to sit down when taking nitrates and stand up slowly afterward. 

Dangerously low blood pressure is also possible with nitrates, especially if you take them with certain medications and substances. Avoid combining nitrates with:

• Sildenafil (Viagra, Revatio) and tadalafil (Cialis, Adcirca)

• Riociguat (Adempas)

• Alcohol

Good to know: Another nitrate, nitroglycerin (Rectiv), is applied topically to treat anal fissure pain. Some medication still gets absorbed into the bloodstream. This can occasionally cause lightheadedness from a drop in blood pressure.

3. PDE5 inhibitors like sildenafil

Phosphodiesterase 5 (PDE5) inhibitors, such as sildenafil and tadalafil, are used for erectile dysfunction and certain lung and prostate conditions. They work by relaxing blood vessels, which can cause a drop in blood pressure. This is usually small, but it can be more significant in certain people.

The risk of hypotension is higher if you combine PDE5 inhibitors with:

• Alpha blockers, which are used for high blood pressure or prostate conditions

• Alcohol, which can amplify their blood pressure-lowering effects

• Nitrates or riociguat, which should be avoided with PDE5 inhibitors

4. Parkinson’s disease medications like pramipexole

Parkinson’s disease (PD) is associated with lower levels of a chemical called norepinephrine, making it harder to regulate blood pressure. And many PD medications, such as pramipexole and levodopa, can further lower blood pressure. This can increase the risk of orthostatic hypotension — a drop in blood pressure when changing positions (such as standing up after sitting). When this happens, it can result in falls or other serious injuries.

To minimize dizziness or fainting, rise slowly from sitting or lying down positions. Your healthcare team may recommend other tips, such as increasing your water or salt intake or adjusting your medications.

5. Opioid pain medications

Opioid pain medications, such as morphine and oxycodone, can cause hypotension (including orthostatic hypotension). This may be more likely to happen in older adults. Combining opioids with alcohol and certain other medications, such as benzodiazepines, may also increase this risk.

Not everyone experiences low blood pressure from opioids. But if you feel dizzy or lightheaded after taking them, let your prescriber know. They can check your medication list for anything that may also be contributing to your symptoms. If needed, they may decide to lower your dose.

6. Antipsychotic medications

Antipsychotic medications can cause orthostatic hypotension, especially at higher doses. This effect is more common with older antipsychotics, like chlorpromazine, or with clozapine (Clozaril) and quetiapine (Seroquel). Antipsychotics like ziprasidone (Geodon) and olanzapine (Zyprexa) may have a lower risk.

For some people, the drops in blood pressure may improve within a few weeks. But they may last longer for others. If you experience ongoing dizziness or other symptoms of low blood pressure, your prescriber may adjust your dose or recommend switching medications.

7. Certain antidepressants

Some antidepressants, such as tricyclic antidepressants (TCAs), trazodone, and monoamine oxidase inhibitors (MAOIs), can cause orthostatic hypotension. That’s because they can relax blood vessels or interfere with blood pressure regulation.

This risk is higher in older adults, those taking higher doses, and people combining antidepressants with other blood pressure-lowering medications. In contrast, selective serotonin reuptake inhibitors (SSRIs) don’t commonly cause orthostatic hypotension. But some SSRIs may interact with blood pressure medications, increasing the risk of hypotension.

Who is at risk for low blood pressure from medications?

Not everyone experiences hypotension from these medications. But your risk may be higher if:

• Your dose is high

• You take multiple medications that lower blood pressure

• You’re age 65 or older

• You’re dehydrated

• You drink a lot of alcohol

• You have a health condition such as Parkinson’s disease, heart failure, or diabetes

Talk to your prescriber if you’re concerned about how your medication may affect your blood pressure. They can provide tips for managing your specific risks and help you recognize symptoms and know when to get help. Share your current medication list so they can screen for potential interactions. 

Tell them if you experience dizziness or lightheadedness, or if your blood pressure readings are lower than they should be. They may need to lower your dose or adjust other medications.

When should you contact your prescriber about low blood pressure?

If you think your blood pressure may be too low, monitor your symptoms and reach out to your prescriber for guidance. To stay safe, try these steps if you feel dizzy or lightheaded:

• Sit or lie down until the dizziness passes.

• If you have a blood pressure monitor at home, take a few readings. A reading below 90 mmHg (top number) and 60 mmHg (bottom number) is typically considered low.

• Once you’re feeling better, stand up slowly to avoid further dizziness or falls. Make sure you have something sturdy to support yourself. Sit back down if you get dizzy.

• Avoid activities that could be dangerous if you’re dizzy, such as driving a car.

There are certain situations where it’s best to go to the ER for low blood pressure. Examples of these include:

• Your blood pressure isn’t improving, especially after a few hours.

• You are experiencing chest pain or heart palpitations.

• Your heart rate is above 100 beats per minute, or below 50 beats per minute.

• You have noticed a significant change in the color or amount of urine. 

• You have heart failure and notice swelling in your leg, ankles, or abdomen.

• You have any symptoms of an infection.

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Written by:

Kristianne Hannemann, PharmD

Kristianne Hannemann, PharmD, is a licensed pharmacist in California. She has been a retail pharmacy manager and staff pharmacist for over 7 years and has contributed drug information content to different health companies.

Edited by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

Reviewed by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

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