The following adverse reactions are discussed in more detail in other sections of the labeling.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

During clinical development, 1,651 subjects were exposed to Lexiscan, with most receiving 0.4 mg as a rapid ( ≤ 10 seconds) intravenous injection. Most of these subjects received Lexiscan in two clinical studies that enrolled patients who had no history of bronchospastic lung disease as well as no history of a cardiac conduction block of greater than first-degree AV block, except for patients with functioning artificial pacemakers. In these studies (Studies 1 and 2), 2,015 patients underwent myocardial perfusion imaging after administration of Lexiscan (N = 1,337) or Adenoscan® (N = 678). The population was 26–93 years of age (median 66 years), 70% male and primarily Caucasian (76% Caucasian, 7% African American, 9% Hispanic, 5% Asian). Table 1 shows the most frequently reported adverse reactions.

Overall, any adverse reaction occurred at similar rates between the study groups (80% for the Lexiscan group and 83% for the Adenoscan group). Aminophylline was used to treat the reactions in 3% of patients in the Lexiscan group and 2% of patients in the Adenoscan group. Most adverse reactions began soon after dosing, and generally resolved within approximately 15 minutes, except for headache which resolved in most patients within 30 minutes.

Table 1 : Adverse Reactions in Studies 1 and 2 Pooled (Frequency ≥ 5%)

N = 1,337
N = 678
Dyspnea 28% 26%
Headache 26% 17%
Flushing 16% 25%
Chest Discomfort 13% 18%
Angina Pectoris or ST Segment Depression 12% 18%
Dizziness 8% 7%
Chest Pain 7% 10%
Nausea 6% 6%
Abdominal Discomfort 5% 2%
Dysgeusia 5% 7%
Feeling Hot 5% 8%

ECG Abnormalities

The frequency of rhythm or conduction abnormalities following Lexiscan or Adenoscan is shown in Table 2 [see WARNINGS AND PRECAUTIONS].

Table 2 : Rhythm or Conduction Abnormalities* in Studies 1 and 2

  Lexiscan N / N evaluable (%) Adenoscan N / N evaluable (%)
Rhythm or conduction abnormalities† 332/1275 (26%) 192/645 (30%)
Rhythm abnormalities 260/1275 (20%) 131/645 (20%)
PACs 86/1274 (7%) 57/645 (9%)
PVCs 179/1274 (14%) 79/645 (12%)
First-degree AV block (PR prolongation > 220 msec) 34/1209 (3%) 43/618 (7%)
Second-degree AV block 1/1209 (0.1%) 9/618 (1%)
AV conduction abnormalities (other than AV blocks) 1/1209 (0.1%) 0/618 (0%)
Ventricular conduction abnormalities 64/1152 (6%) 31/581 (5%)
*12-lead ECGs were recorded before and for up to 2 hrs after dosing
† includes rhythm abnormalities (PACs, PVCs, atrial fibrillation/flutter, wandering atrial pacemaker, supraventricular or ventricular arrhythmia) or conduction abnormalities, including AV block

Respiratory Abnormalities

In a randomized, placebo-controlled trial (Study 3) of 999 subjects with asthma (n= 532) or stable chronic obstructive pulmonary disease (n=467), the overall incidence of pre-specified respiratory adverse reactions was greater in the Lexiscan group compared to the placebo group (p < 0.001). Most respiratory adverse reactions resolved without therapy; a few subjects received aminophylline or a short acting bronchodilator. No differences were observed between treatment arms in the reduction of > 15% from baseline at two-hours in FEV1 (Table 3).

Table 3 : Respiratory Adverse Effects in Study 3*

  Asthma Cohort COPD Cohort
Overall Pre-specified Respiratory Adverse Reaction† 12.90% 2.30% 19.00% 4.00%
  Dyspnea 10.70% 1.10% 18.00% 2.60%
  Wheezing 3.10% 1.10% 0.90% 0.70%
FEV1 reduction > 15%‡ 1.10% 2.90% 4.20% 5.40%
*All subjects continued the use of their respiratory medications as prescribed prior to administration of Lexiscan.
†Patients may have reported more than one type of adverse reaction. Adverse reactions were collected up to 24 hours following drug administration. Pre-specified respiratory adverse reactions included dyspnea, wheezing, obstructive airway disorder, dyspnea exertional, and tachypnea.
‡Change from baseline at 2 hours

Renal Impairment

In a randomized, placebo-controlled trial of 504 subjects (Lexiscan n=334 and placebo n=170) with a diagnosis or risk factors for coronary artery disease and NKFK/DOQI Stage III or IV renal impairment (defined as GFR 15-59 mL/min/1.73 m²), no serious adverse events were reported through the 24-hour follow-up period.

Post-Marketing Experience


Myocardial infarction, cardiac arrest, ventricular arrythmias, supraventricular tachyarrythmias including atrial fibrillation or flutter, heart block (including third degree block), asystole, marked hypertension, symptomatic hypotension in association with transient ischemic attack, seizures and syncope [see WARNINGS AND PRECAUTIONS] have been reported. Some events required intervention with fluids and/or aminophylline. QTc prolongation shortly after Lexiscan administration has been reported.

Central Nervous System

Tremor, seizure (particularly with a history of seizure)


Abdominal pain, occasionally severe, has been reported a few minutes after Lexiscan administration, in association with nausea, vomiting, or myalgias; administration of aminophylline, an adenosine antagonist, appeared to lessen the pain. Diarrhea and fecal incontinence have also been reported following Lexiscan administration.


Anaphylaxis, angioedema, cardiac or respiratory arrest, respiratory distress, decreased oxygen saturation, hypotension, throat tightness, urticaria, rashes have occurred and have required treatment including resuscitation [see WARNINGS AND PRECAUTIONS].


Musculoskeletal pain has occurred, typically 10-20 minutes after Lexiscan administration; the pain was occasionally severe, localized in the arms and lower back and extended to the buttocks and lower legs bilaterally. Administration of aminophylline appeared to lessen the pain.


Respiratory arrest, dyspnea and wheezing have been reported following Lexiscan administration.

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to Lexiscan exposure.

Read the Lexiscan (regadenoson injection) Side Effects Center for a complete guide to possible side effects


No formal pharmacokinetic drug interaction studies have been conducted with Lexiscan.

Effects Of Other Drugs On Lexiscan

  • Methylxanthines (e.g., caffeine and theophylline) are non-specific adenosine receptor antagonists that interfere with the vasodilation activity of Lexiscan [see CLINICAL PHARMACOLOGY and PATIENT INFORMATION]. Patients should avoid consumption of any products containing methylxanthines as well as any drugs containing theophylline for at least 12 hours before Lexiscan administration. Aminophylline may be used to attenuate severe or persistent adverse reactions to Lexiscan [see OVERDOSAGE].
  • In clinical studies, Lexiscan was administered to patients taking other cardioactive drugs (i.e., β-blockers, calcium channel blockers, ACE inhibitors, nitrates, cardiac glycosides, and angiotensin receptor blockers) without reported adverse reactions or apparent effects on efficacy.
  • Dipyridamole may change the effects of Lexiscan. When possible, withhold dipyridamole for at least two days prior to Lexiscan administration.

Effect Of Lexiscan On Other Drugs

Regadenoson does not inhibit the metabolism of substrates for CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, or CYP3A4 in human liver microsomes, indicating that it is unlikely to alter the pharmacokinetics of drugs metabolized by these cytochrome P450 enzymes.

Read the Lexiscan Drug Interactions Center for a complete guide to possible interactions

Last reviewed on RxList: 1/21/2014
This monograph has been modified to include the generic and brand name in many instances.


Report Problems to the Food and Drug Administration


You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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