From the Guidelines
For an 83-year-old patient with BPH, diabetes, hypertension, and orthostatic hypotension, 5-alpha reductase inhibitors (5-ARIs) such as finasteride (5mg daily) or dutasteride (0.5mg daily) would be the most appropriate alternatives to tamsulosin. These medications work by inhibiting the conversion of testosterone to dihydrotestosterone, causing prostate shrinkage over time (typically 3-6 months for noticeable improvement), without significantly affecting blood pressure, as supported by the AUA guideline on management of benign prostatic hyperplasia 1. Unlike alpha-blockers which relax smooth muscle and can worsen orthostatic hypotension, 5-ARIs have minimal cardiovascular effects, making them suitable for this patient with existing orthostatic hypotension. The main drawbacks include a slower onset of action compared to alpha-blockers and potential side effects like decreased libido, erectile dysfunction, and gynecomastia. Regular PSA monitoring is important, as these medications typically reduce PSA levels by about 50% after 6-12 months of treatment, as noted in the guideline 1. For more immediate symptom relief while waiting for 5-ARIs to take effect, the patient might benefit from behavioral modifications such as fluid restriction before bedtime, avoiding caffeine and alcohol, and scheduled voiding. Additionally, considering the patient's orthostatic hypotension, it is recommended to pursue non-pharmacological approaches as the first-line treatment, and to switch BP-lowering medications that worsen orthostatic hypotension to an alternative BP-lowering therapy, as suggested by the 2024 ESC guidelines for the management of elevated blood pressure and hypertension 1. Some key points to consider when prescribing 5-ARIs include:
- They are appropriate and effective treatments for patients with LUTS associated with demonstrable prostatic enlargement, as stated in the AUA guideline 1
- They can reduce the size of the prostate, increase peak urinary flow rate, and reduce BPH symptoms, as supported by the guideline 1
- They have minimal cardiovascular effects, making them a suitable option for patients with orthostatic hypotension, as noted in the guideline 1
- Regular monitoring of PSA levels is necessary, as 5-ARIs can reduce PSA levels by about 50% after 6-12 months of treatment, as mentioned in the guideline 1.
From the Research
Alternative Treatment Options for BPH
Given the patient's condition, an alternative to tamsulosin that has minimal effect on blood pressure is needed.
- Finasteride, a 5-alpha reductase inhibitor, can be considered as it has been shown to improve urinary symptoms in patients with BPH, especially in those with enlarged prostates 2.
- Finasteride has a lower risk of asthenia, dizziness, and postural hypotension compared to alpha-blockers such as doxazosin and terazosin 2.
- However, finasteride may have a higher risk of impotence, erectile dysfunction, decreased libido, and ejaculation disorder compared to alpha-blockers 2.
Considerations for Orthostatic Hypotension
- Orthostatic hypotension is a common condition in the elderly, and its treatment is imperfect 3, 4.
- The patient's orthostatic hypotension may be managed with a combination of fludrocortisone, a pressor agent (midodrine or droxidopa), and procedures to improve orthostatic defenses during periods of increased orthostatic stress 3.
- It is essential to educate the patient on the management of orthostatic hypotension and to monitor their condition closely.
Food and Medication Interactions
- The patient should be aware of potential interactions between their medications and food, particularly with alpha-1 adrenergic receptor antagonists and 5-alpha reductase inhibitors 5.
- Grapefruit juice and citrus fruits may intensify the adverse effects of alpha-1 adrenergic receptor antagonists, while alcohol may lead to orthostatic hypotension 5.