Some people taking metoprolol notice that their fingers or toes feel unusually cold.

Mayo Clinic lists paleness or a cold feeling in the fingertips and toes among potential less-common effects, while more significant circulation-related symptoms may require medical attention.

A little coldness is not automatically dangerous.

However, if your fingers or toes become very cold, pale, blue, numb, painful, or noticeably different from before, tell your healthcare professional.

Those symptoms can have causes unrelated to metoprolol as well, so an evaluation is more useful than guessing.

9. Digestive changes or dry mouth

Metoprolol can sometimes affect the digestive system.

Possible effects include diarrhea, bloating, indigestion, gas, constipation, or a dry mouth, depending on the person and formulation. MedlinePlus lists diarrhea and dry mouth among possible side effects, while Mayo Clinic lists several additional digestive symptoms.

These symptoms may seem minor, which is one reason people don’t always mention them.

If they are persistent, severe, or interfering with eating, drinking, or daily life, bring them up at your next appointment.

10. Changes in blood sugar warning signs

This one is especially important for people with diabetes.

Metoprolol can affect how some warning signs of low blood sugar are noticed. In particular, beta-blockers can mask certain symptoms, such as a fast heartbeat, that normally alert someone that their blood sugar may be falling.

That doesn’t mean people with diabetes cannot take metoprolol. It means they should understand how their medication can affect the way hypoglycemia presents.

If you have diabetes and take metoprolol, ask your healthcare professional what symptoms you should watch for and how you should monitor your blood sugar.

Some symptoms should not be brushed off

Most medication side effects are not emergencies.

But some symptoms while taking metoprolol require prompt medical attention.

MedlinePlus advises contacting a doctor immediately or seeking emergency treatment for symptoms such as difficulty breathing, significant swelling, fainting, rapid or irregular heartbeats, or unusual weight gain.

Mayo Clinic also advises prompt medical attention for problems such as chest pain, severe breathing difficulty, significant swelling, worsening heart-failure symptoms, or major changes in heartbeat.

If symptoms are severe or sudden, especially chest pain, severe shortness of breath, fainting, or a serious change in consciousness, seek emergency medical care.

Don’t stop metoprolol suddenly

This may be the most important medication-related point in the entire article.

If metoprolol is making you feel tired, dizzy, or uncomfortable, it can be tempting to simply stop taking it.

Don’t do that without talking to your healthcare professional.

MedlinePlus specifically warns that suddenly stopping metoprolol can lead to serious heart problems. Mayo Clinic likewise recommends discussing any planned discontinuation with your doctor, who may reduce the dose gradually when appropriate.

The right response to a troublesome side effect is usually a conversation with the prescriber, not abruptly stopping treatment.

Why keeping a symptom record can help

If you think metoprolol may be causing a new symptom, keep a simple record for several days.

Write down:

• When you take your medication
• When the symptom appears
• How long it lasts
• Your blood pressure, if your doctor has asked you to monitor it
• Your heart rate, if you have been instructed to monitor it
• Any other medications or supplements you take
• Whether the symptom is getting better, worse, or staying the same

This gives your healthcare professional something much more useful than simply saying, “I don’t feel right.”

It may also help identify whether the problem is related to metoprolol, another medication, your underlying condition, or something unrelated.

A medication review can be worthwhile

If you take several medications, don’t assume that every new symptom comes from metoprolol.

Other prescription drugs, over-the-counter medicines, supplements, and medical conditions can contribute to dizziness, fatigue, sleep problems, low blood pressure, or changes in blood sugar.

MedlinePlus recommends telling your doctor or pharmacist about all prescription and nonprescription medicines, vitamins, supplements, and herbal products you take because interactions can sometimes require changes in treatment.

A complete medication review can therefore be more useful than focusing on one drug in isolation.

The bottom line

Metoprolol is an established medication used for several important cardiovascular conditions, and for many people its benefits are significant.

But side effects can happen.

Tiredness, dizziness, changes in exercise tolerance, sleep problems, mood changes, sexual side effects, cold extremities, digestive symptoms, and changes in blood-sugar warning signs are among the effects that may deserve discussion with a healthcare professional.

The important distinction is between recognizing a possible side effect and deciding what to do about it.

If a symptom is new, persistent, worsening, or interfering with your daily life, bring it up with your doctor or pharmacist.

And never stop metoprolol abruptly without medical guidance.

Sometimes a small conversation about a symptom can lead to a medication adjustment, a different explanation, or simply reassurance that everything is working as intended.