From the Guidelines
Pindolol is less likely to cause orthostatic hypotension compared to other beta-blockers, such as alpha-1 blockers like Doxazosin, Prazosin, and Terazosin, which are associated with orthostatic hypotension, especially in older adults 1. Pindolol is a non-selective beta-blocker with intrinsic sympathomimetic activity (ISA), which means it partially activates beta receptors while blocking them. This partial agonist activity helps maintain some degree of sympathetic tone at rest, resulting in less reduction of cardiac output and peripheral vascular resistance. When patients stand up, the ISA properties of pindolol help preserve the compensatory cardiovascular responses needed to maintain blood pressure, reducing the risk of orthostatic symptoms like dizziness or fainting. The typical dosage of pindolol ranges from 10-60 mg daily, administered in two doses, as indicated in the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults 1. While pindolol is less likely to cause orthostasis, patients should still be advised to rise slowly from sitting or lying positions, particularly when first starting the medication. Monitoring blood pressure in both sitting and standing positions during initial therapy is advisable, especially in elderly patients who are more susceptible to orthostatic effects of any cardiovascular medication. Some key points to consider when managing orthostatic hypotension include:
- Identifying and addressing underlying causes, such as volume depletion or medication side effects 1
- Implementing non-pharmacological measures, such as gradual postural changes, increased fluid and salt intake, and use of elastic garments 1
- Considering pharmacological treatment, such as midodrine or fludrocortisone, if symptoms persist despite non-pharmacological measures 1.
From the FDA Drug Label
The effect on blood pressure is not orthostatic, i.e., pindolol was equally effective in reducing the supine and standing blood pressure.
The answer to the question about pindolol and orthostasis is that pindolol does not have an orthostatic effect on blood pressure, as it is equally effective in reducing both supine and standing blood pressure 2.
From the Research
Pindolol and Orthostasis
- Pindolol, a beta-adrenoceptor antagonist with partial agonist activity, has been studied for its effects on orthostatic hypotension 3.
- In a study of three bedridden patients with severe orthostatic hypotension, pindolol (15 mg/day) was found to be therapeutically effective in maintaining standing blood pressure above 90/50 mm Hg 3.
- The study also reported increases in supine heart rate, stroke volume, and cardiac output, as well as supine blood pressure, in patients taking pindolol 3.
Mechanism of Action
- Pindolol's intrinsic sympathomimetic activity is thought to contribute to its ability to manage mild and moderate hypertension without causing orthostatic hypotension 4.
- However, the development of tolerance to pindolol and other beta-blocking agents with intrinsic sympathomimetic activity may be explained by a decrease in beta-adrenergic receptor density 5.
Comparison to Other Treatments
- Fludrocortisone, a mineralocorticoid, is considered a first- or second-line pharmacological therapy for orthostatic hypotension, alongside mechanical and positional measures 6.
- Midodrine and droxidopa have been found to possess the most evidence for increasing blood pressure and alleviating symptoms in primary orthostatic hypotension 7.
- Pyridostigmine and fludrocortisone can be used in patients who fail to respond to midodrine and droxidopa, while emerging evidence suggests that low-dose atomoxetine may be a viable alternative treatment option 7.