Gabapentin and Pregabalin Can Cause Hypotension
Yes, both gabapentin and pregabalin can cause hypotension, particularly orthostatic hypotension, as a side effect. This risk is especially important to consider in elderly patients, those with cardiovascular disease, and patients taking other medications that may lower blood pressure.
Mechanism and Risk Factors
Gabapentinoids (gabapentin and pregabalin) can cause hypotension through several mechanisms:
- Both medications can cause fluid retention and peripheral edema 1
- They may have effects on calcium channels that contribute to cardiovascular side effects 2
- Neurological side effects like dizziness and somnolence can exacerbate orthostatic symptoms 3
Risk factors that increase the likelihood of hypotension with these medications include:
- Advanced age
- Pre-existing cardiovascular disease
- Concomitant use of other medications that lower blood pressure
- Renal impairment (both drugs are eliminated unchanged in urine) 4
Evidence from Guidelines and Drug Information
The American Heart Association acknowledges that anticonvulsants such as gabapentin and pregabalin require renal dose adjustment and are "typically not recommended because of risk of fluid retention, weight gain, and heart failure exacerbation" 1. This suggests that the hemodynamic effects of these medications can be clinically significant.
The FDA label for gabapentin specifically mentions dizziness as a common side effect, occurring in 28% of gabapentin-treated patients versus 8% in placebo-treated patients 3. While not explicitly labeled as orthostatic hypotension, dizziness is often a clinical manifestation of this condition.
Clinical Implications
The cardiovascular risks of gabapentinoids appear to extend beyond just hypotension. A 2022 study found that both gabapentin and pregabalin were associated with increased risk of several cardiovascular events in patients with diabetic neuropathy, including heart failure, with hazard ratios of 1.14 and 1.20 respectively 5.
When prescribing these medications:
- Start with low doses and titrate slowly, especially in elderly patients or those with cardiovascular disease
- Monitor for signs of orthostatic hypotension (dizziness, lightheadedness upon standing)
- Be cautious when combining with other medications that can cause hypotension
- Consider renal function when dosing, as impaired clearance can increase side effects
Special Considerations
- Combination therapy with both gabapentin and pregabalin should be avoided, as this can increase the risk of adverse effects including dizziness 6
- Patients with heart failure may be particularly vulnerable to the fluid retention effects of these medications 2
- Elderly patients require lower starting doses and slower titration due to increased risk of side effects 7
In conclusion, while hypotension is not among the most commonly reported adverse effects of gabapentinoids, the evidence suggests it is a real concern, particularly in vulnerable populations. Clinicians should maintain awareness of this potential side effect when prescribing these widely used medications.