What about orthostatic hypotension in patients taking Tadalafil (tadalafil)?

From the Guidelines

Patients taking tadalafil should be aware of the potential for orthostatic hypotension, which can be minimized by rising slowly from sitting or lying positions, staying well-hydrated, and avoiding excessive alcohol consumption. Orthostatic hypotension is a drop in blood pressure that occurs when changing positions, particularly when standing up from sitting or lying down, and is a common issue in approximately 10% of all hypertensive adults and up to 50% of older institutionalized adults 1. This effect is caused by the vasodilation properties of tadalafil, which can be exacerbated by other medications that lower blood pressure, such as alpha-blockers, nitrates, or multiple antihypertensive medications.

To diagnose orthostatic hypotension, blood pressure should be measured at 1 min and/or 3 min after standing, with a threshold for orthostatic hypotension of ≥20/10 mmHg (systolic BP/diastolic BP) drop 1. If dizziness, lightheadedness, or fainting occurs, patients should sit or lie down immediately and seek medical attention if symptoms are severe or persistent. Elderly patients and those with pre-existing cardiovascular conditions should be particularly cautious, as orthostatic hypotension can increase the risk of falls and fractures 1.

Some key points to consider when managing orthostatic hypotension in patients taking tadalafil include:

• Ensuring adequate salt intake and avoiding medications that aggravate hypotension
• Using compressive garments over the legs and abdomen
• Encouraging physical activity and exercise to avoid deconditioning
• Volume repletion with fluids and salt is critical 1
• Rising slowly from sitting or lying positions
• Staying well-hydrated
• Avoiding excessive alcohol consumption

It's also important to note that the orthostatic effect of tadalafil can occur at any time during the drug's active period, which may last up to 36 hours. Therefore, patients should be aware of the potential for orthostatic hypotension and take steps to minimize their risk.

From the FDA Drug Label

Patients should be made aware that both alcohol and tadalafil, a PDE5 inhibitor, act as mild vasodilators. When mild vasodilators are taken in combination, blood-pressure-lowering effects of each individual compound may be increased. Therefore, physicians should inform patients that substantial consumption of alcohol (e.g., 5 units or greater) in combination with tadalafil can increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache [see Clinical Pharmacology (12.2)].

Orthostatic hypotension is a potential risk when taking tadalafil, particularly when combined with substantial consumption of alcohol. Patients should be informed of this risk and advised to be cautious when consuming alcohol while taking tadalafil 2.

• Key points:
  • Tadalafil and alcohol are mild vasodilators
  • Combination of tadalafil and alcohol can increase the potential for orthostatic signs and symptoms
  • Patients should be cautious when consuming alcohol while taking tadalafil
  • Orthostatic hypotension is a potential risk when taking tadalafil, especially with alcohol consumption 2, 2

From the Research

Orthostatic Hypotension in Patients Taking Tadalafil

• Orthostatic hypotension is a significant drop in blood pressure that occurs when standing up from sitting or lying down, which can lead to dizziness, lightheadedness, or fainting 3, 4, 5.
• Tadalafil, a phosphodiesterase 5 inhibitor, is used to treat erectile dysfunction and has been shown to have minimal blood pressure-lowering effects in healthy volunteers 6.
• However, when combined with other medications, such as nitric oxide donors or alpha-blocking agents, tadalafil can lead to severe hypotension, which is a contraindication 6.
• In patients with hypertension, orthostatic hypotension can be an independent risk factor for falls and overall mortality, and its management can be challenging due to the need to balance blood pressure control with the risk of worsening orthostatic hypotension 5.
• The treatment of orthostatic hypotension in patients taking tadalafil should focus on removing drugs that can worsen the condition, such as tamsulosin, tizanidine, sildenafil, trazodone, and carvedilol, and using alternative medications that can help improve blood pressure control 5.

Management of Orthostatic Hypotension

• The management of orthostatic hypotension in patients taking tadalafil should involve a stepwise approach, including behavioral, nonpharmacologic, and pharmacologic strategies 4.
• Patients should be screened for orthostatic hypotension, and those with a history of falls or syncope should be closely monitored 3, 4.
• Abdominal binders and acarbose can be used to prevent orthostatic hypotension and postprandial hypotension, respectively, without increasing baseline blood pressure 5.
• Atomoxetine and pyridostigmine can be used to improve upright blood pressure by harnessing residual sympathetic tone and facilitating cholinergic neurotransmission in autonomic ganglia 5.
• Midodrine and droxidopa can be used as traditional pressor agents, administered at the lowest dose and frequency that improves symptoms 5.

Special Considerations

• Patients with multiple system atrophy may be at higher risk of developing orthostatic hypotension when taking tadalafil or other phosphodiesterase 5 inhibitors, such as sildenafil 7.
• Measurement of lying and standing blood pressure should be performed before prescribing tadalafil or other phosphodiesterase 5 inhibitors to patients with parkinsonism, and patients should be made aware of the risk of orthostatic hypotension and the need to seek medical advice if symptoms occur 7.