Palpitations: Drugs That Cause or Treat Them

What Palpitations Actually Are

Palpitations describe a subjective awareness of the heartbeat, whether it feels fast, slow, irregular, or simply too forceful. The sensation itself is not a diagnosis. It is a symptom that can stem from dozens of cardiac and non-cardiac causes, and its clinical significance ranges from completely benign to life-threatening.

A 2019 systematic review published in the British Journal of General Practice found that palpitations account for approximately 0.56% of all primary care consultations in the UK, making them among the top 20 cardiac-related reasons for a GP visit [1]. Among patients presenting to emergency departments with palpitations, a prospective cohort study (N=381) found that only 17.4% had a clinically significant arrhythmia detected on initial evaluation [2]. The remaining majority had benign etiologies: anxiety, caffeine intake, dehydration, or medication side effects.

The 2015 ACC/AHA/HRS clinical guideline for the management of supraventricular tachycardia states: "A thorough history remains the single most important diagnostic tool in the evaluation of palpitations" [3]. That history should include timing, duration, associated symptoms like presyncope or dyspnea, and a complete medication review. The medication review matters because drug-induced palpitations are among the most correctable causes.

Drugs That Commonly Cause Palpitations

Beta-agonists, stimulants, and vasoactive medications top the list of pharmaceutical triggers. Recognizing the offending agent often resolves the symptom without any additional pharmacotherapy.

Sympathomimetic agents are the most frequent offenders. Albuterol (salbutamol), used by over 27 million Americans with asthma or COPD, causes palpitations in 7 to 20% of users depending on dose and delivery method [4]. Short-acting beta-2 agonists stimulate cardiac beta-1 receptors at higher doses, increasing heart rate by 10 to 20 beats per minute. Pseudoephedrine, available over the counter, raises blood pressure and heart rate through alpha-1 and beta-1 adrenergic stimulation. A randomized crossover trial (N=48) showed that a single 60 mg dose of pseudoephedrine increased systolic blood pressure by a mean of 5.4 mmHg and heart rate by 2.7 bpm, with palpitations reported by 12.5% of participants [5].

Thyroid hormones are another well-documented cause. Levothyroxine, prescribed to roughly 10% of women over age 60 in the United States, can provoke palpitations when doses push TSH below the reference range. A retrospective analysis of 17,684 patients on levothyroxine found that those with suppressed TSH (<0.1 mIU/L) had a 3.1-fold increased risk of atrial fibrillation compared to euthyroid controls [6].

CNS stimulants prescribed for ADHD, including amphetamine salts (Adderall) and methylphenidate (Ritalin, Concerta), carry palpitations as a listed adverse effect in 2 to 10% of clinical trial participants [7]. The mechanism is direct catecholamine release. Lisdexamfetamine (Vyvanse) showed a mean heart rate increase of 4.3 bpm in the key adult ADHD trial (N=420) [7].

Other notable drug triggers include:

• Digoxin, which can cause both bradyarrhythmias and tachyarrhythmias at toxic levels (serum digoxin >2.0 ng/mL)
• Theophylline, a phosphodiesterase inhibitor with a narrow therapeutic window
• Tricyclic antidepressants (amitriptyline, nortriptyline), which block cardiac sodium channels and prolong the QT interval
• Fluoroquinolone antibiotics (moxifloxacin in particular), associated with QT prolongation and torsades de pointes in rare cases [8]

The 2023 AHA scientific statement on drug-induced arrhythmias notes: "Clinicians should maintain a high index of suspicion for medication-related causes in any patient presenting with new-onset palpitations, especially when the temporal relationship to drug initiation or dose change is clear" [9].

Drugs That Treat Palpitations

Treatment depends entirely on the underlying rhythm disturbance. For the majority of patients with benign ectopy or sinus tachycardia, beta-blockers are the first choice.

Beta-blockers reduce heart rate and suppress ectopic beats by blocking cardiac beta-1 adrenergic receptors. Metoprolol succinate, starting at 25 mg daily and titrated to 100 to 200 mg daily, is the most commonly prescribed agent for symptomatic palpitations in the outpatient setting. A meta-analysis of 7 randomized trials (N=1,354) showed that beta-blockers reduced premature ventricular contraction (PVC) burden by a mean of 48% compared to placebo [10]. Propranolol (10 to 40 mg three times daily) is preferred when anxiety coexists with palpitations because of its lipophilic blood-brain barrier penetration. Bisoprolol (2.5 to 10 mg daily) offers once-daily dosing with high beta-1 selectivity.

Calcium channel blockers of the non-dihydropyridine class serve as second-line rate-control agents. Diltiazem (120 to 360 mg daily in extended-release form) and verapamil (120 to 480 mg daily) slow conduction through the AV node. The 2023 ACC/AHA/ACCP/HRS guideline for SVT management recommends IV verapamil (5 to 10 mg) or IV diltiazem (0.25 mg/kg) as first-line acute treatment for hemodynamically stable AVNRT or AVRT when vagal maneuvers fail [3]. Oral formulations are used for chronic suppression in patients who cannot tolerate beta-blockers.

Antiarrhythmic drugs are reserved for confirmed, recurrent, or hemodynamically significant arrhythmias. Class IC agents, flecainide (50 to 150 mg twice daily) and propafenone (150 to 300 mg three times daily), are effective for atrial fibrillation and SVT suppression in patients with structurally normal hearts. The CAST trial famously demonstrated that flecainide and encainide increased mortality in post-MI patients, so these agents are strictly contraindicated in structural heart disease [11]. Amiodarone (200 mg daily maintenance after loading) remains the most effective antiarrhythmic across multiple rhythm disturbances but carries serious long-term toxicities to thyroid, lung, liver, and skin.

Catheter ablation has become the definitive treatment for many supraventricular tachycardias. For AVNRT, radiofrequency ablation achieves a success rate above 95% with a complication rate below 1% [3]. While not a drug, ablation deserves mention here because it often replaces lifelong pharmacotherapy.

When Palpitations Signal Something Dangerous

Most palpitations are benign, but certain features demand urgent evaluation. Missing these red flags can be fatal.

Syncope during palpitations raises concern for ventricular tachycardia or high-degree AV block. A 2016 study in the European Heart Journal (N=1,329 consecutive palpitation presentations) found that syncope was the single strongest predictor of a malignant arrhythmia, with an odds ratio of 4.31 (95% CI: 2.18 to 8.51) [12]. Palpitations occurring during exertion, lasting longer than 5 minutes, or accompanied by chest pain also warrant prompt ECG and monitoring.

Family history of sudden cardiac death before age 40 should trigger screening for inherited channelopathies (long QT syndrome, Brugada syndrome, catecholaminergic polymorphic VT). An ECG showing a corrected QT interval >500 ms, pre-excitation (delta waves), or epsilon waves shifts the clinical picture from benign to potentially life-threatening.

The recommended initial workup for palpitations includes a 12-lead ECG, complete blood count, basic metabolic panel (looking for hypokalemia or hypomagnesemia), and TSH. If the initial ECG is normal and episodes are infrequent, extended monitoring with a Holter monitor (24 to 48 hours) or event recorder (2 to 4 weeks) is appropriate [13]. Patients with structurally abnormal hearts on echocardiography may require electrophysiology study.

Caffeine, Alcohol, and Other Non-Prescription Triggers

The relationship between caffeine and palpitations is more nuanced than most patients believe. Moderate coffee intake does not appear to increase arrhythmia risk in the general population.

A large prospective cohort study from the UK Biobank (N=386,258, median follow-up 4.5 years) found no significant association between habitual coffee consumption (up to 6 cups per day) and incident atrial fibrillation (HR 0.97; 95% CI: 0.93 to 1.01) or other clinically significant arrhythmias [14]. A separate UCSF study using continuous ambulatory monitoring (N=100) showed that coffee consumption did not increase the daily burden of premature atrial contractions or premature ventricular contractions [15].

Alcohol tells a different story. The term "holiday heart syndrome" describes atrial fibrillation triggered by acute alcohol intake, first described in 1978. The ALCOHOL-AF randomized controlled trial (N=140) demonstrated that abstinence from alcohol in regular drinkers with paroxysmal AF reduced arrhythmia recurrence by 37% (HR 0.63; 95% CI: 0.46 to 0.87; P=0.005) over 6 months [16]. This remains one of the strongest pieces of evidence supporting a modifiable lifestyle intervention for arrhythmia control.

Other non-prescription triggers include energy drinks (which combine caffeine with taurine and other stimulants), nicotine from cigarettes or vaping, cannabis (which can cause sinus tachycardia acutely), and dietary supplements containing synephrine or yohimbine.

The Hormone Connection

Palpitations frequently surface during periods of hormonal flux. Menopause, pregnancy, and thyroid dysfunction are the three most common endocrine-related triggers.

Perimenopausal palpitations affect roughly 25 to 40% of women during the menopausal transition [17]. Fluctuating estrogen levels alter cardiac ion channel expression and modulate autonomic tone. The Study of Women's Health Across the Nation (SWAN) found that reported palpitations correlated with declining estradiol levels independent of hot flashes or anxiety [17]. Hormone replacement therapy (HRT) may alleviate symptoms in some women, though the relationship between exogenous estrogen and atrial fibrillation risk is complex. The Women's Health Initiative showed a non-significant trend toward increased AF in the estrogen-plus-progestin arm (HR 1.09; 95% CI: 0.94 to 1.26) [18].

Hyperthyroidism remains one of the most important correctable causes of palpitations. Graves' disease, toxic multinodular goiter, and excessive levothyroxine supplementation all increase cardiac beta-adrenergic receptor density and sensitivity. Atrial fibrillation occurs in 10 to 15% of patients with overt hyperthyroidism [6]. Treatment of the underlying thyroid disorder with methimazole (starting at 10 to 30 mg daily) or radioactive iodine typically resolves the palpitations within weeks.

Testosterone replacement therapy (TRT) in men has generated mixed signals regarding arrhythmia risk. The TTrials (Testosterone Trials, N=788) did not identify a statistically significant increase in palpitations or arrhythmias in men receiving testosterone gel versus placebo over 12 months [19]. The TRAVERSE trial (N=5,204) confirmed cardiovascular safety of testosterone replacement regarding major adverse cardiovascular events but was not powered specifically for arrhythmia endpoints [20].

Managing Palpitations Without Medication

For patients whose palpitations are benign and not caused by a correctable medication, non-pharmacologic strategies can reduce symptom frequency and severity.

Vagal maneuvers work acutely. The Valsalva maneuver (bearing down against a closed glottis for 15 seconds, then releasing while supine with legs elevated to 45 degrees) terminates AVNRT in approximately 43% of cases when performed correctly using the modified technique described in the REVERT trial (N=428) [21]. Carotid sinus massage is an alternative but should be avoided in patients with carotid bruits or known carotid artery disease.

Stress reduction has measurable effects. A randomized trial of yoga-based intervention (N=80) in patients with paroxysmal AF showed a 31% reduction in symptomatic AF episodes and significantly lower anxiety and depression scores over 3 months [22]. Cognitive behavioral therapy has demonstrated efficacy for palpitations associated with panic disorder.

Sleep optimization matters. Obstructive sleep apnea (OSA) is an independent risk factor for atrial fibrillation. A meta-analysis of 11 studies (N=3,135) found that untreated OSA doubled the risk of AF recurrence after catheter ablation (OR 2.25; 95% CI: 1.61 to 3.13) [23]. Treatment with continuous positive airway pressure (CPAP) reduced this risk substantially.

Electrolyte repletion should not be overlooked. Hypokalemia (<3.5 mEq/L) and hypomagnesemia (<1.7 mg/dL) lower the threshold for both atrial and ventricular ectopy. Patients on thiazide or loop diuretics are particularly vulnerable. Target serum potassium above 4.0 mEq/L and magnesium above 2.0 mg/dL in patients with recurrent palpitations.