Does tadalafil make your heart race? Tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor licensed in the UK for erectile dysfunction and benign prostatic hyperplasia, can occasionally cause cardiovascular sensations including palpitations. Whilst most patients tolerate tadalafil well, some report awareness of their heartbeat or a racing sensation. These effects typically result from mild systemic vasodilation and compensatory cardiovascular responses rather than direct cardiac stimulation. Understanding when such symptoms are benign versus concerning is essential for safe use. This article examines the evidence, identifies warning signs requiring medical attention, and provides guidance on managing cardiovascular effects whilst taking tadalafil.

Does Tadalafil Make Your Heart Race?

Tadalafil is a phosphodiesterase type 5 (PDE5) inhibitor licensed in the UK for treating erectile dysfunction and benign prostatic hyperplasia. Whilst tadalafil is generally well-tolerated, some patients report cardiovascular symptoms including palpitations or a sensation of their heart racing. Understanding whether tadalafil directly causes these effects requires examining its mechanism of action and clinical evidence.

How Tadalafil Affects the Cardiovascular System

Tadalafil works by inhibiting PDE5, an enzyme that breaks down cyclic guanosine monophosphate (cGMP) in smooth muscle cells. This leads to vasodilation, primarily in the corpus cavernosum for erectile function, but also causes mild systemic vasodilation. The resulting drop in blood pressure triggers compensatory mechanisms, including a modest increase in heart rate in some individuals. Clinical trials have demonstrated that tadalafil typically causes a small reduction in blood pressure with minimal effect on heart rate in most patients.

Clinical Evidence on Heart Rate Changes

According to the Summary of Product Characteristics (SmPC), palpitations are classified as an uncommon side effect of tadalafil (affecting between 1 in 100 and 1 in 1,000 patients). True tachycardia (heart rate exceeding 100 beats per minute) is less common. When patients report their heart racing, this may sometimes reflect awareness of normal cardiovascular responses during sexual activity. However, individual responses vary, and some patients may be more sensitive to the haemodynamic changes induced by tadalafil. The MHRA's Yellow Card scheme has received reports of palpitations associated with tadalafil use, though establishing direct causation remains challenging given multiple confounding factors including anxiety, physical exertion, and underlying cardiovascular conditions.

When to Seek Medical Advice About Heart Symptoms

Whilst mild cardiovascular sensations may occur with tadalafil, certain symptoms warrant immediate medical attention. Patients should be educated to recognise warning signs that require urgent assessment, as distinguishing between benign side effects and serious cardiac events is crucial for safety.

Red Flag Symptoms Requiring Immediate Action

Patients should seek emergency medical care (call 999 or attend A&E) if they experience:

• Chest pain or pressure, particularly if radiating to the jaw, neck, or left arm

• Severe breathlessness or difficulty breathing at rest

• Rapid heart rate accompanied by dizziness, light-headedness, or fainting

• Irregular heartbeat (arrhythmia) with associated chest discomfort

These symptoms may indicate serious conditions including myocardial infarction, unstable angina, or significant arrhythmias that require immediate intervention regardless of tadalafil use.

Non-Urgent Symptoms Requiring Medical Review

Patients should contact their GP or prescribing clinician if they experience:

• Persistent palpitations lasting more than a few minutes after resting

• Recurrent palpitations that resolve spontaneously but occur with each dose

• New-onset awareness of heartbeat that causes concern or anxiety

• Mild chest discomfort that does not fit the pattern of cardiac pain

• Unexplained fatigue or reduced exercise tolerance since starting tadalafil

If these symptoms occur when GP services are unavailable, or if patients are uncertain about the urgency, they should contact NHS 111 for advice.

A thorough cardiovascular assessment, including history, examination, and potentially investigations such as an electrocardiogram (ECG), blood tests for electrolytes, and thyroid function tests can help determine whether symptoms are related to tadalafil or reflect underlying cardiac pathology. The GP may consider dose adjustment, alternative treatments, or referral to cardiology depending on findings.

Safe Use of Tadalafil: Precautions and Contraindications

Tadalafil carries specific contraindications and precautions related to cardiovascular health. Prescribers must conduct thorough cardiovascular risk assessment before initiating treatment, and patients should be aware of circumstances where tadalafil use is inadvisable or requires specialist supervision.

Contraindications

According to the SmPC, tadalafil is contraindicated in patients:

• Taking nitrate medications (e.g., glyceryl trinitrate, isosorbide mononitrate) for angina, as the combination can cause life-threatening hypotension

• Using nicorandil, a potassium-channel activator with nitrate-like properties

• Taking riociguat, a soluble guanylate cyclase stimulator used for pulmonary hypertension

• With hypersensitivity to tadalafil or any of the excipients

Patients for whom sexual activity is inadvisable

Tadalafil should not be used in patients:

• With recent myocardial infarction (within 90 days)

• With unstable angina or angina occurring during sexual intercourse

• With stroke within the last 6 months

• With severe heart failure (NYHA Class III-IV) or uncontrolled arrhythmias

• With hypotension (blood pressure below 90/50 mmHg) or uncontrolled hypertension

Cardiovascular Risk Assessment

UK guidance emphasises cardiovascular risk assessment before prescribing PDE5 inhibitors. The Princeton Consensus guidelines, while not specifically endorsed by NICE, provide a framework for categorising patients as low, intermediate, or high cardiovascular risk. Those at intermediate or high risk may require cardiology assessment, including exercise tolerance testing, before tadalafil is deemed safe. Sexual activity itself represents moderate physical exertion (approximately 3-5 METs), equivalent to climbing two flights of stairs, which may be problematic for patients with limited cardiac reserve.

Drug Interactions and Precautions

Caution is advised when combining tadalafil with:

• Alpha-blockers (e.g., tamsulosin, doxazosin)—patients should be stable on alpha-blocker therapy before starting tadalafil at the lowest dose; the combination with doxazosin is particularly problematic due to additive hypotensive effects

• Antihypertensive medications, which may require dose adjustment

• CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, erythromycin) that increase tadalafil plasma concentrations

• CYP3A4 inducers (e.g., rifampicin, carbamazepine) that can reduce tadalafil efficacy

Special Populations

In severe renal or hepatic impairment, tadalafil should be used with caution. Daily dosing is not recommended in these patients. Patients with anatomical cardiac abnormalities, left ventricular outflow obstruction, or autonomic dysfunction require individualised assessment before tadalafil prescription.

Managing Side Effects While Taking Tadalafil

Most tadalafil-related side effects are mild and transient, but patients benefit from practical strategies to minimise discomfort and optimise treatment outcomes. Effective side effect management improves adherence and patient satisfaction whilst maintaining safety.

Common Side Effects and Their Management

According to the SmPC, the most frequently reported adverse effects of tadalafil include:

• Headache (common)—often responds to simple analgesia such as paracetamol; typically diminishes with continued use

• Flushing (facial warmth and redness)—usually mild and self-limiting; staying well-hydrated may help

• Dyspepsia (indigestion)—taking tadalafil with food or using antacids can provide relief

• Nasal congestion—saline nasal sprays may help; avoid sympathomimetic decongestants (e.g., pseudoephedrine) which can worsen palpitations or hypertension

• Back pain or myalgia—usually resolves within 48 hours and responds to standard analgesics

Serious Side Effects Requiring Urgent Medical Attention

Patients should seek immediate medical attention if they experience:

• Priapism (painful erection lasting more than 4 hours)—a medical emergency requiring prompt treatment

• Sudden vision loss or disturbance—may indicate non-arteritic anterior ischaemic optic neuropathy (NAION)

• Sudden hearing loss or tinnitus—a rare but serious adverse effect

Dose Optimisation

If cardiovascular sensations or other side effects prove troublesome, dose adjustment may be appropriate. Tadalafil is available in multiple strengths (2.5mg, 5mg, 10mg, 20mg for erectile dysfunction; 5mg for benign prostatic hyperplasia). Starting with the lowest effective dose and titrating upwards as needed can minimise adverse effects whilst maintaining therapeutic benefit. For daily dosing regimens, the lower doses (2.5-5mg) generally produce fewer side effects than on-demand higher doses.

Lifestyle Modifications

Patients can reduce the likelihood of side effects by:

• Avoiding excessive alcohol consumption, which potentiates hypotensive effects and may worsen palpitations

• Staying well-hydrated, particularly in warm environments

• Timing doses appropriately—taking tadalafil when able to rest if side effects occur

• Monitoring response patterns—keeping a symptom diary helps identify triggers and patterns

Important Safety Reminder

Patients should remember that nitrates must not be taken within at least 48 hours of using tadalafil. If chest pain develops, patients must inform healthcare professionals about tadalafil use so alternative emergency treatments can be provided.

When to Consider Alternative Treatments

If side effects persist despite dose adjustment and management strategies, alternative PDE5 inhibitors (sildenafil, vardenafil, avanafil) may be better tolerated due to different pharmacokinetic profiles. Non-pharmacological options, including vacuum erection devices, intracavernosal injections, or psychological interventions, should be discussed with healthcare providers. Patients should never discontinue prescribed medications without medical consultation.

Patients who experience suspected side effects from tadalafil are encouraged to report them through the MHRA Yellow Card scheme (yellowcard.mhra.gov.uk or via the Yellow Card app).

Frequently Asked Questions