From the Guidelines
Ivabradine is a reasonable treatment option for patients with symptomatic Postural Orthostatic Tachycardia Syndrome (POTS), as it has been shown to reduce heart rate and improve symptoms in patients with inappropriate sinus tachycardia (IST), a condition similar to POTS, as evidenced by a small randomized crossover trial 1. The medication works by selectively inhibiting the funny sodium channel (If) in the sinoatrial node, which slows heart rate without affecting blood pressure or cardiac contractility. For POTS treatment, ivabradine is typically started at 2.5-5 mg twice daily and can be titrated up to 7.5 mg twice daily based on response and tolerance, as seen in a study where ivabradine given at a dosage of 2.5 to 7.5 mg twice daily significantly reduced daytime heart rate from 98.4 ± 11.2 at baseline to 84.7 ± 9.0, compared with 98.6 ± 11.1 on placebo (p<0.001) 1. Some key points to consider when using ivabradine for POTS include:
- The medication is generally well-tolerated with the most common side effects being phosphenes (visual brightness phenomena) and bradycardia, as reported in 3% of patients taking the drug in the SHIFT trial 1.
- Ivabradine is particularly useful for patients who cannot tolerate beta-blockers due to fatigue or hypotension.
- Treatment duration is individualized, with some patients requiring long-term therapy while others may eventually reduce or discontinue the medication as their condition improves.
- Ivabradine should be used as part of a comprehensive treatment approach that includes increased fluid and salt intake, graduated exercise, and management of other POTS symptoms.
From the Research
Evidence for Ivabradine in POTS
- Ivabradine has been shown to be effective in reducing heart rate and improving symptoms in patients with Postural Orthostatic Tachycardia Syndrome (POTS) 2, 3, 4, 5, 6
- Studies have demonstrated that ivabradine can decrease heart rate and myocardial oxygen consumption at rest and during exercise, making it a potential treatment option for POTS 2, 3
- A systematic review of 13 articles found that ivabradine lowered heart rate and provided symptomatic relief of POTS without lowering blood pressure 5
- Common side effects of ivabradine in POTS patients include dizziness, nausea, headache, and fatigue, but these often do not lead to discontinuation of treatment 3, 5
Efficacy of Ivabradine in POTS
- A retrospective evaluation of pediatric patients with POTS found that 68% of patients experienced improvement in symptoms with ivabradine treatment 2
- A single-center experience with ivabradine in POTS patients found that 78% of patients reported significant improvement in symptoms, with a significant decrease in sitting and standing heart rate 3
- A study on the effects of heart rate lowering with ivabradine on symptom burden in POTS patients found a significant reduction in the change in heart rate with standing and a significant reduction in symptom burden 4
Safety and Tolerability of Ivabradine in POTS
- Ivabradine has been shown to be safe and well-tolerated in POTS patients, with few patients discontinuing treatment due to side effects 2, 3, 5
- The most common side effect of ivabradine in POTS patients is luminous phenomena/visual brightness, but this is often not severe enough to lead to discontinuation of treatment 3