What is the incidence of chest pain in patients taking Losartan (angiotensin II receptor antagonist)?

Incidence of Chest Pain in Patients Taking Losartan

Chest pain is a rare side effect of losartan, occurring in approximately 2% of patients, which is only slightly higher than the incidence in patients taking placebo. 1

Evidence on Chest Pain with Losartan

The FDA drug label for losartan indicates that chest pain is reported as a less common adverse reaction 1. In clinical trials involving over 1,000 patients on various doses of losartan and over 300 patients on placebo, chest pain was not among the common adverse events that occurred in ≥2% of patients and more frequently than placebo 1.

In the Reduction of Endpoints in NIDDM with the Angiotensin II Receptor Antagonist Losartan (RENAAL) study involving 1,513 patients, chest pain was reported with an incidence of ≥4% in patients treated with losartan and occurred with ≥2% difference compared to placebo 1.

Differentiating Chest Pain Types

When a patient on losartan reports chest pain, it's important to differentiate between:

1. Drug-related chest pain: Usually non-ischemic and not associated with other cardiac symptoms
2. Cardiac ischemic pain: Typically builds gradually in intensity over minutes, may be associated with exertion, and can be accompanied by dyspnea, palpitations, diaphoresis, or lightheadedness 2
3. Non-cardiac causes: Such as musculoskeletal pain (which can be localized and affected by movement) or gastrointestinal causes 2

Clinical Assessment of Chest Pain in Losartan Users

When evaluating chest pain in a patient taking losartan, consider:

• Timing: Sudden onset of chest pain shortly after starting losartan may suggest a drug reaction, as seen in a case report of losartan-induced coronary artery spasm occurring 15 minutes after first dose 3
• Character: Anginal symptoms typically build gradually in intensity over minutes, while sudden ripping pain suggests aortic syndrome 2
• Location: Pain that can be localized to a very limited area or radiates below the umbilicus is unlikely to be myocardial ischemia 2
• Associated symptoms: Presence of dyspnea, palpitations, diaphoresis, lightheadedness may suggest cardiac origin 2
• Triggers: Positional chest pain is usually non-ischemic (e.g., musculoskeletal) 2

Management Considerations

For patients experiencing chest pain while on losartan:

1. Evaluate for cardiac causes: ECG should be performed, especially when clinical suspicion of ACS is high 2
2. Consider alternative medications: If chest pain appears related to losartan, consider switching to another antihypertensive agent
3. Rule out other causes: Assess for other potential causes of chest pain as outlined in guidelines 2

Special Considerations

• Losartan is associated with a lower incidence of cough compared to ACE inhibitors (17% vs 69%), making it a suitable alternative for patients who develop cough on ACE inhibitors 1
• Losartan has been shown to be well-tolerated in clinical practice with an overall incidence of adverse experiences similar to that of placebo 4, 5, 6
• In elderly patients with hypertension, the incidence of treatment-related adverse events with losartan (19-27%) was similar to calcium channel blockers but better tolerated than captopril and atenolol 5

While chest pain can occur with losartan use, it is relatively uncommon. When it does occur, thorough evaluation is necessary to determine whether it represents a drug side effect or indicates a more serious underlying condition.