Are Heart Palpitations and a Racing Heart Normal During Benzodiazepine Withdrawal?

Key Takeaways

• Palpitations and a racing heart are common and expected during benzodiazepine withdrawal, and in an otherwise healthy heart they are usually not dangerous.
• The heart races because the nervous system has lost some of its brake after the dose falls, and fear of the pounding adds more adrenaline on top.
• With a short-acting drug such as Xanax (alprazolam), palpitations often appear between doses, which is one reason the Ashton Manual recommends a crossover taper to diazepam for many people.
• New palpitations deserve one proper evaluation by the prescriber, with a pulse and blood pressure reading, an electrocardiogram, and blood tests for thyroid function and electrolytes, because other causes can feel the same from the inside.
• Call 911 for chest pain or pressure, fainting, shortness of breath at rest, a pulse that stays very fast at rest, or a rhythm that feels chaotic, and call or text 988 for a mental health crisis.
• Palpitations that flare after each reduction mean the last cut was more than the nervous system could absorb, and the answer is a change of pace agreed with the prescriber, a short hold at the present dose and a smaller next step for some patients and a steady pace for others, never an abrupt stop.
• Caffeine, nicotine, energy drinks, decongestants, and alcohol all push the heart in the wrong direction during a taper, while slow breathing and gentle activity help in the moment.
• Withdrawal palpitations fade as the nervous system settles, in windows and waves, and a pulse written down once or twice a day beside the dose history helps the prescriber more than a wrist device checked every few minutes.

Are palpitations and a racing heart a normal part of benzodiazepine withdrawal?

In most cases, yes. Palpitations are the awareness of one’s own heartbeat: the heart seems to race, pound, flutter, or skip. During benzodiazepine withdrawal they are common and expected, and in an otherwise healthy heart they are usually not dangerous.

Professor C. Heather Ashton lists palpitations, together with flushing and sweating, in the table of withdrawal symptoms in Chapter III of the Ashton Manual. When the United States Food and Drug Administration (FDA) required updated benzodiazepine labeling in 2020, the labels listed a fast heart rate (tachycardia) and high blood pressure among the signs of acute withdrawal.

Palpitations rarely arrive alone. Patients often describe sweating, flushing, a fine tremor, a tight chest, lightheadedness, and a surge of fear that something is wrong with the heart itself. That fear is reasonable. What does the pounding mean, and when is it something more?

The heart races because the nervous system has lost its brake.

Benzodiazepines strengthen gamma-aminobutyric acid (GABA), the brain’s main calming signal. The first chapter of the Manual describes GABA’s message as an inhibitory one that tells neurons to slow down or stop firing. It adds that benzodiazepines lower the brain’s output of excitatory messengers, including norepinephrine, a close relative of adrenaline.

After months or years of a daily dose, the nervous system adjusts to that extra braking. When the dose falls, the brake eases before the system has readjusted, and the sympathetic nervous system, the body’s alerting side, runs ahead for a while. It is like a car with the idle set too high. Nothing is wrong with the engine, yet it revs while standing still.

Anxiety then adds to the problem. A pounding heart is alarming, alarm releases more adrenaline, and adrenaline makes the heart pound harder. In Chapter III, Professor Ashton writes that palpitations, a pounding heart, and a rapid pulse do not signify heart or lung disease, and are simply the expression of an overactive autonomic nervous system.

This adaptation has a name, physical dependence, and it happens to people who took their medication exactly as prescribed. Physical dependence is not addiction. The difference matters here, because the remedy for a dependent nervous system is a slower taper, not a treatment model built for a different problem.

Why do palpitations come between doses of Xanax?

Xanax (alprazolam) is short acting. The drug table in the first chapter of the Ashton Manual gives it a half-life of 6 to 12 hours, so the blood level rises and falls several times a day.

Chapter II describes these peaks and troughs and notes that many people feel a small withdrawal between each dose. That is interdose withdrawal, and the heart is often where it is felt. A person who takes Xanax three times a day may notice the pounding late in the morning, in the early evening, and in the small hours, shortly before each dose is due.

Klonopin (clonazepam) lasts longer, 18 to 50 hours in the same table, so the dips are shallower and symptoms tend to appear later after a reduction. Diazepam (Valium) lasts longer still, at 20 to 100 hours.

So, the Manual recommends a crossover taper to diazepam for many people on short-acting drugs. A longer-acting drug keeps the level even, and the heart has less to react to.

Unfortunately, a racing heart can have other causes, and they should be ruled out.

While withdrawal is the usual explanation for palpitations that begin during a taper, it does not protect anyone from an unrelated problem. An overactive thyroid, an electrolyte imbalance, dehydration, a cold remedy, or a rhythm disturbance in the heart itself can feel the same from the inside.

So, new palpitations are worth one proper evaluation by the prescriber. That usually means a history of when the episodes happen in relation to doses and reductions, a pulse and blood pressure reading, an electrocardiogram (ECG), blood tests for thyroid function and electrolytes, and a review of every other medication and supplement.

When the tests are normal and the episodes track the dose changes, the patient can stop wondering about the heart and attend to the taper. In most cases the rhythm turns out to be a normal one running fast, which doctors call sinus tachycardia.

Blood pressure can rise during withdrawal for the same reason, so both are worth measuring. A person with known heart disease needs closer monitoring through a taper, and both the prescriber and the cardiologist should know the plan.

Chest pain, fainting, and breathlessness need emergency care.

A slower taper is the wrong tool for some symptoms. Chest pain or pressure is one, especially when it comes with exertion or spreads to the arm, jaw, or back. Fainting, shortness of breath at rest, a pulse that stays very fast at rest, and a rhythm that feels chaotic instead of fast and regular are the others.

Call 911 for any of these, for a seizure, or for any other medical emergency. A person with known heart disease should not wait. For a mental health crisis or thoughts of suicide, the 988 Suicide & Crisis Lifeline answers calls and texts at any hour.

No article can tell a panic surge from a cardiac event, and often the patient cannot either. In fact, being examined and told the heart is fine is a good outcome. A companion article explains when a racing heart in withdrawal needs same-day care.

Fortunately, the main remedy is a slower taper.

Palpitations that flare after each reduction are information. They say the last cut was more than the nervous system could absorb. One answer is a short hold, in which the patient stays at the present dose for a time before a smaller next step. Everybody is different, though, and some patients do better continuing at a steady pace than waiting out a long hold, so the change is planned with the prescriber and the medication is never stopped suddenly.

In Chapter II, Professor Ashton proposes steps of up to one tenth of the dose, permits standing still for a few weeks, and writes that the person tapering is usually the best judge of the pace. She prefers holding to going back up. Yet, where a cut has proved too large, a small step back up is a legitimate choice to make with the prescriber.

The Maudsley Deprescribing Guidelines add the hyperbolic shape: every reduction is sized to the dose that remains, so the cuts get smaller as the taper goes on. Either way, a taper is measured in months, and sometimes in more than a year.

Dr. Mark Leeds, an osteopathic physician and deprescribing specialist in Fort Lauderdale, Florida, uses the crossover to diazepam where it helps and hyperbolic reductions as the dose gets low. Palpitations are one of the signals that set the pace.

Stopping abruptly is never the answer to a frightening symptom. The Manual warns that abrupt or over-rapid withdrawal can cause convulsions, and the FDA’s 2020 update states that abrupt discontinuation or rapid dose reduction can bring on life-threatening withdrawal reactions.

What about medication for the palpitations?

Chapter III of the Manual notes that in a few cases severe palpitations or tremor hinder progress in withdrawal, and that medication can control or lessen them. Such a medication treats the symptom. The withdrawal itself is unchanged.

Which medication, if any, fits is a patient-specific decision for a physician who knows the patient, made with the risks discussed first and the right to decline. A medication for a symptom carries risks of its own, and it is never a reason to taper faster.

Caffeine, decongestants, stimulants, and alcohol push the heart in the wrong direction.

Caffeine, nicotine, and energy drinks all speed the heart. So do the decongestants in many cold and allergy remedies, and so do stimulant medications, which are a matter to raise with the prescriber, not something to stop alone.

In Chapter III, Professor Ashton allows coffee or tea in moderation for most people. However, a patient whose main symptom is a racing heart has good reason to be stricter with caffeine until the heart settles.

Alcohol works on the same GABA receptors as a benzodiazepine, so it is best avoided during a taper. A drink in the evening can calm the heart for a few hours and leave it pounding at three in the morning, and it can unsettle the taper itself. Chapter II warns against compensating for a falling dose with alcohol.

Slow breathing and gentle activity help in the moment. The Manual advises slow, deep breathing during an episode, and a daily walk, regular meals, enough fluids, and a steady bedtime are sensible habits for a long taper. Yet, they are support. The treatment is the slower taper.

Checking the pulse at home helps when it is limited. A reading once or twice a day, taken seated and written down beside the dose history, gives the prescriber something to work with. A wrist device consulted every few minutes mostly feeds the fear.

Patients also ask about Klonopin, Xanax, and the heart.

Does Klonopin (clonazepam) slow the heart rate?

Not in a way that explains symptoms during a taper. The Klonopin label lists a drop in blood pressure on standing as an infrequent effect, and it does not list a slow heart rate. Withdrawal pushes the pulse up. So, a persistently slow pulse needs a check by the prescriber for another cause, and a slow pulse with fainting is a reason to call 911.

Can Klonopin or Xanax cause palpitations while a person is still taking it?

Yes. The Klonopin label lists palpitations among its reported adverse reactions, as an infrequent one. Dependence at a steady prescribed dose is another explanation: the first chapter of the Manual describes people on short-acting benzodiazepines who develop anxiety symptoms between doses while taking the drug as prescribed.

Can Klonopin stop a heart attack?

No. Klonopin is not a heart medication. It may quiet the panic that comes with chest symptoms, but it does nothing for a blocked artery, and taking an extra dose for chest pain delays the care that matters. Chest pain is a reason to call 911.

Withdrawal palpitations fade as the nervous system settles.

Many patients worry that a heart which has pounded for months is being worn out. In an otherwise healthy heart, these symptoms are not signs of injury. They come from an overactive nervous system, and they ease as that system settles.

Unfortunately, how long that takes varies, and no one can promise a date. Professor Ashton describes withdrawal symptoms in Chapter III as waxing and waning, with windows of feeling well that lengthen and come more often. Palpitations follow the same pattern, even near the end of a taper.

Dr. Leeds’ practice in Fort Lauderdale is a concierge practice, not an insurance practice, and it focuses on medically supervised tapering off of benzodiazepines and z-drug sleeping pills for patients in Florida. Each taper is gradual, directed by the patient, and slowed when symptoms such as palpitations show that the pace is too fast. Contact the office to discuss a supervised taper.

This article is educational. It is not medical advice, and reading it does not create a doctor-patient relationship. Decisions about starting, continuing, or tapering any medication should be made with your own physician.