Terazosin, an alpha-blocker commonly prescribed for high blood pressure and benign prostatic hyperplasia (BPH), can have serious interactions with certain medications and supplements, primarily due to the risk of dangerously low blood pressure (hypotension). It is crucial to be aware of these interactions to ensure patient safety.
Specifically, drugs that should not be taken with terazosin include sildenafil, tamsulosin, vardenafil, and yohimbe.
Key Medications and Substances to Avoid
Combining terazosin with certain substances can lead to an amplified effect on blood pressure, causing dizziness, fainting, or more severe cardiovascular events. Understanding the categories of these interacting drugs helps in recognizing similar risks.
1. Phosphodiesterase-5 (PDE5) Inhibitors
These medications are primarily used to treat erectile dysfunction (ED) and pulmonary arterial hypertension. When taken with terazosin, they can cause a significant and sudden drop in blood pressure.
- Sildenafil (Viagra, Revatio)
- Vardenafil (Levitra, Staxyn)
Patients taking terazosin should inform their healthcare provider about their blood pressure medication before starting any PDE5 inhibitor. Often, a lower dose of the PDE5 inhibitor or a different treatment strategy may be necessary, or these combinations may be contraindicated entirely.
2. Other Alpha-Blockers
Taking terazosin with other alpha-blockers, which have a similar mechanism of action, can lead to an additive effect on blood pressure lowering, increasing the risk of severe hypotension.
- Tamsulosin (Flomax)
This interaction is particularly concerning because both terazosin and tamsulosin are commonly used for BPH. If a patient is on one alpha-blocker, adding another without careful medical supervision is highly discouraged.
3. Herbal Supplements
Certain herbal supplements can also affect blood pressure and interact with terazosin.
- Yohimbe
Yohimbe is an herbal supplement often marketed for erectile dysfunction or athletic performance. It can have stimulant properties and also affect blood pressure, leading to adverse reactions when combined with terazosin. It's always important to discuss any herbal supplements you are taking with your doctor.
Understanding the Risks of Drug Interactions
The primary risk associated with these interactions is severe hypotension, which can manifest as:
- Dizziness or Lightheadedness: Especially when standing up quickly (orthostatic hypotension).
- Fainting (Syncope): A sudden loss of consciousness due to insufficient blood flow to the brain.
- Falls: Increased risk, particularly in older adults.
- Stroke or Heart Attack: In severe cases, extreme drops in blood pressure can lead to critical organ damage.
Important Considerations
- Always Inform Your Doctor: Before starting any new medication, including over-the-counter drugs, herbal remedies, or supplements, always inform your healthcare provider about all current medications you are taking.
- Read Medication Guides: Pay close attention to the medication guides and patient information leaflets provided with your prescriptions, as they often list important interaction warnings.
- Monitor Symptoms: If you experience any symptoms of low blood pressure (e.g., dizziness, blurred vision, weakness) after taking terazosin, especially when combined with other medications, seek immediate medical attention.
Summary of Drugs to Avoid with Terazosin
To ensure safety and prevent adverse effects, individuals taking terazosin should avoid the following drugs due to serious interaction risks:
| Drug Category | Specific Drugs to Avoid | Primary Concern |
|---|---|---|
| PDE5 Inhibitors | Sildenafil, Vardenafil | Severe Hypotension |
| Other Alpha-Blockers | Tamsulosin | Additive Hypotensive Effect |
| Herbal Supplements | Yohimbe | Adverse Blood Pressure Effects |
For more comprehensive information on terazosin, including its uses, side effects, and further interactions, consult a reliable drug information resource like RxList. Always follow your healthcare provider's advice regarding your medications.
