What is Alfuzosin and How Does It Work?
Alfuzosin, often known by its brand name Uroxatral, is a prescription medication primarily used to treat the symptoms of benign prostatic hyperplasia (BPH), or an enlarged prostate [1.4.3, 1.4.5]. BPH is a non-cancerous condition where the prostate gland enlarges, leading to urinary problems like a weak stream, frequent urination, and a feeling of incomplete bladder emptying [1.4.5].
Alfuzosin belongs to a class of drugs called alpha-1 adrenergic antagonists [1.4.2]. Its mechanism of action involves selectively blocking alpha-1 receptors located in the smooth muscle of the prostate, bladder neck, and prostatic urethra [1.4.1]. By blocking these receptors, the medication causes the muscles to relax [1.4.1, 1.4.3]. This relaxation improves urine flow and reduces the bothersome lower urinary tract symptoms associated with BPH [1.4.1]. The medication is formulated as an extended-release tablet that should be taken with food at the same meal each day [1.3.5].
The Central Question: Can Alfuzosin Cause Diarrhea?
Yes, alfuzosin can cause diarrhea [1.3.6]. While it is not one of the most common side effects, it is a recognized gastrointestinal issue associated with the medication. In official drug information, diarrhea is listed as a side effect identified during post-marketing experience, meaning it was reported by patients after the drug became widely available [1.2.1, 1.3.2]. Some patients may experience gastrointestinal side effects such as abdominal pain, nausea, and diarrhea, which are typically described as mild and transient [1.7.2].
Understanding the Frequency of Side Effects
The most frequently reported side effects of alfuzosin are not gastrointestinal. They include:
- Dizziness (up to 27%) [1.3.2]
- Headache (up to 14%) [1.3.2]
- Fatigue (up to 14%) [1.3.2]
- Upper respiratory tract infection (up to 14%) [1.3.2]
In contrast, gastrointestinal issues like abdominal pain, dyspepsia (indigestion), constipation, and nausea are listed as common but occur in a smaller percentage of patients, typically between 1% and 10% [1.2.1, 1.3.2]. Diarrhea falls into a category of side effects with an unknown incidence rate or those reported after initial clinical trials [1.3.2, 1.7.3]. The mechanism by which alpha-blockers cause diarrhea is thought to be related to their effect on smooth muscle; by blocking alpha-1 receptors, they can increase peristaltic movement in the intestines and relax the anal sphincter, leading to looser stools [1.8.4].
Comparison of Side Effects: Alfuzosin vs. Other Alpha-Blockers
To provide context, it's useful to compare alfuzosin with other common alpha-blockers used for BPH. The side effect profiles can influence a doctor's prescription choice, especially for sexually active patients or those with specific health concerns.
| Side Effect | Alfuzosin (Uroxatral) | Tamsulosin (Flomax) | General Alpha-Blockers |
|---|---|---|---|
| Dizziness | Occurs in ~6% of patients [1.9.3]. | Reported in 15-17% of patients [1.9.3]. | A very common side effect across the class [1.8.2]. |
| Abnormal Ejaculation | Lower rate of ejaculatory issues [1.6.2, 1.6.4]. | Reported in 8-18% of patients [1.9.3]. | A known side effect, particularly with tamsulosin [1.6.1]. |
| Diarrhea | A recognized post-marketing side effect [1.2.1]. | Reported in 0.1-1% of patients [1.8.4]. Also listed as a more common side effect [1.8.3]. | A possible side effect for the entire class [1.8.2]. |
| Headache | Occurs in ~3% of patients [1.9.3]. | Occurs in 19-21% of patients [1.9.3]. | A common side effect [1.6.5]. |
Managing Medication-Induced Diarrhea
If you experience mild diarrhea while taking alfuzosin, there are several self-care steps you can take. However, it is crucial to consult your healthcare provider before trying any new treatments or stopping your medication.
Do's:
- Stay Hydrated: Drink plenty of fluids like water, broths, or sports drinks to replace lost water and electrolytes [1.5.1, 1.5.4].
- Adjust Your Diet: Gradually introduce low-fiber, semisolid foods like toast, rice, chicken, or eggs [1.5.4]. Avoid high-fiber, fatty, spicy, or greasy foods for a few days [1.5.2, 1.5.4].
- Eat Small, Frequent Meals: This can be gentler on your digestive system than large meals [1.5.2].
- Practice Good Skin Care: The skin around the anus can become irritated. Keep the area clean and dry. Sitz baths (warm, shallow baths) can also provide relief [1.5.2].
Don'ts:
- Don't Stop Your Medication Abruptly: Never stop taking alfuzosin without first consulting the prescribing doctor.
- Don't Self-Medicate Without Approval: Do not take anti-diarrheal medicines like loperamide (Imodium) without your doctor's okay, as these can sometimes worsen certain types of infections [1.5.2, 1.5.4].
When to Contact a Healthcare Provider
You should contact your doctor if the diarrhea:
- Is severe, persistent, or worsens over time [1.2.3].
- Is accompanied by fever, severe abdominal pain, or blood in the stool [1.5.5].
- Occurs with other serious symptoms like rash, swelling of the face or throat, fainting, or chest pain [1.2.5, 1.7.4].
Conclusion: A Manageable Side Effect
In conclusion, while alfuzosin can cause diarrhea, it is considered a less common side effect compared to others like dizziness and headache [1.2.1, 1.3.2]. It is listed as a gastrointestinal disorder identified in post-marketing reports, indicating it is a real but not primary adverse event [1.3.6]. The effect is generally mild and may resolve as your body adapts to the medication [1.7.2].
Patients should be aware of this possibility and manage mild symptoms with hydration and dietary adjustments [1.5.4]. Most importantly, any bothersome, severe, or persistent side effects should be discussed with a healthcare provider. Open communication ensures that the treatment for BPH remains effective while managing any unwanted effects on quality of life. For more detailed drug information, a reliable resource is the National Library of Medicine's MedlinePlus.
