When a beta blocker is not a safe choice

Why screening matters for an 'as-needed' tablet

It is easy to think of a pre-presentation tablet as harmless. But a beta blocker slows the heart, lowers blood pressure and can narrow the airways in sensitive people. In a healthy adult those effects are usually mild. In someone with an undiagnosed or poorly controlled heart or lung condition, they can be serious.

Your HealifyMD assessment asks about these conditions directly, and your clinician may follow up with questions about symptoms such as wheezing, fainting or breathlessness before deciding.

What the assessment asks

Expect questions about any history of asthma, wheezing or chronic cough; fainting or dizzy spells; a slow pulse or known heart rhythm problem; heart failure or chest pain; diabetes and the medicines you use for it; thyroid disease; and severe allergic reactions. You will also be asked to list current medicines and supplements and whether you are pregnant or breastfeeding.

Answer as fully as you can. If you are unsure about something, such as whether a childhood diagnosis of asthma still counts, say so; your clinician can follow up rather than guess.

Lung conditions

Beta blockers like propranolol are 'non-selective,' meaning they also act on receptors in the airways. Blocking those receptors can tighten the airways and trigger wheezing or an asthma attack. MedlinePlus advises that your doctor may tell you not to take propranolol if you have asthma or other lung disease, and the National Institute of Mental Health notes that beta blockers generally are not recommended for people with asthma.

This applies even if your asthma is mild or you rarely need an inhaler. COPD and other chronic lung conditions raise similar concerns.

Heart rhythm, heart failure and low blood pressure

Because beta blockers slow the heart, they are generally avoided in people whose heart is already slow or whose electrical signals are delayed, such as some types of heart block. MedlinePlus lists slow or irregular heartbeat and heart failure among the conditions where you may be told not to take propranolol.

If your blood pressure is naturally low, or you have fainted in the past, a beta blocker may cause lightheadedness or fainting. Your clinician will ask about these episodes and may recommend checking your resting heart rate and blood pressure before deciding.

Diabetes and low blood sugar

MedlinePlus notes that propranolol can increase the risk of low blood sugar and may hide its warning signs, such as a fast heartbeat and shakiness. That matters most if you use insulin or a sulfonylurea. NIMH also says beta blockers generally are not recommended for people with diabetes when used for anxiety. If you have diabetes, your clinician will weigh whether the benefit for an occasional event justifies the risk.

Other conditions that need a closer look

• Overactive thyroid: a beta blocker can mask symptoms such as a fast heartbeat
• Liver or kidney disease, which can change how the drug is processed
• Severe allergies: reactions may be worse and may respond less to usual doses of epinephrine
• Pheochromocytoma, a rare adrenal tumor
• Circulation problems in the hands and feet, such as Raynaud's
• Depression, since some people report low mood or fatigue on beta blockers
• Pregnancy or breastfeeding, which require an individual discussion

Medicines and substances that interact

Combining a beta blocker with other medicines that slow the heart or lower blood pressure can push both too low. Some calcium channel blockers, other beta blockers, certain heart rhythm drugs and clonidine are examples your clinician will ask about. MedlinePlus also lists interactions with cimetidine, aluminum-containing antacids and anti-inflammatory painkillers such as ibuprofen.

Alcohol can raise propranolol levels, and smoking may reduce how well it works. Tell your clinician about everything you take, including supplements and anything prescribed by another doctor.

If you already take a beta blocker

Some people are already on a daily beta blocker for blood pressure, migraine or heart rhythm. In that case an extra tablet for performance nerves may not be appropriate, and your prescribing doctor should be involved. MedlinePlus warns that stopping propranolol suddenly can cause serious heart problems, so never stop a daily beta blocker without medical advice.

Warning signs after taking a dose

Seek urgent care for wheezing or trouble breathing, swelling of the face or throat, fainting, or chest pain. Dizziness, tiredness and cold hands are more common and usually pass. If you are not a candidate, your clinician can talk through other approaches, such as therapy or different medicines. When a beta blocker is appropriate, the HealifyMD price is $149 one-time, confirmed at the eligibility review.