From the Guidelines
Managing drug-induced syncope requires prompt discontinuation or dose adjustment of the offending medication, along with supportive care, as reducing or withdrawing medications that may cause hypotension can be beneficial in selected patients with syncope. According to the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1, several drug classes have been implicated in syncope, including diuretics, vasodilators, venodilators, negative chronotropes, and sedatives.
Key Considerations
- The prevalence of medication-related syncope appears higher in older patients 1.
- Close supervision during adjustment of medications is frequently required because of potential worsening of preexisting supine hypertension or cardiac arrhythmias 1.
- Other factors to consider include frailty, HF and/or cardiac dysfunction, and the use of a large number of medications causing adverse effects because of drug-drug interactions 1.
Management Strategies
- Place the patient in a supine position with elevated legs to improve cerebral blood flow.
- Consider alternative drugs, reduced dosages, or modified administration schedules after the acute episode.
- Implement preventive strategies such as taking medications while seated or lying down, rising slowly from sitting/lying positions, ensuring adequate hydration, and avoiding alcohol.
- Long-term management should include patient education about medication side effects and warning symptoms.
Medications Implicated in Syncope
- Diuretics (furosemide, hydrochlorothiazide)
- Vasodilators (nitroglycerin)
- Antiarrhythmics (amiodarone, sotalol)
- Antihypertensives (especially beta-blockers like metoprolol and ACE inhibitors like lisinopril)
- Psychiatric medications (tricyclic antidepressants, antipsychotics)
- Certain antibiotics (fluoroquinolones)
From the FDA Drug Label
If the blood pressure falls 15 mm Hg or more, PA administration should be temporarily discontinued
- Management of drug-induced syncope involves close monitoring of the patient's vital signs and electrocardiograms.
- If syncope occurs, temporary discontinuation of the drug may be necessary, as indicated by a drop in blood pressure of 15 mm Hg or more.
- ECG monitoring is advisable for early detection of any tendency to excessive widening of the QRS complex, prolongation of the P-R interval, or any signs of heart block 2.
From the Research
Management of Drug-Induced Syncope
To manage drug-induced syncope, it is essential to identify the underlying cause and adjust pharmacological therapy accordingly. The following steps can be taken:
- Obtain an accurate drug history to determine if any medications are contributing to syncope 3
- Review the patient's medication list to identify potential offending agents, such as anti-hypertensive medications, nitrates, beta blockers, and other drugs that can cause orthostatic hypotension 4, 5
- Consider alternative medications or dosage adjustments to minimize the risk of syncope 3
- Monitor patients for signs of orthostatic hypotension, such as dizziness or lightheadedness, and adjust treatment accordingly 6
Treatment Options
Treatment options for drug-induced syncope may include:
- Discontinuation of the offending medication 4
- Adjustment of the medication dosage or regimen 3
- Addition of medications to manage orthostatic hypotension, such as alpha-adrenoceptor agonists or midodrine 6
- Lifestyle modifications, such as increasing fluid and salt intake, to help manage orthostatic hypotension 6
Importance of Accurate Diagnosis
Accurate diagnosis of the underlying cause of syncope is crucial to guide management and prevent further episodes. A thorough evaluation, including a detailed medical history, physical examination, and laboratory tests, can help identify the cause of syncope and inform treatment decisions 7.