Uroxatral (alfuzosin) Side Effects, Warnings, and Drug Interactions

Uroxatral (alfuzosin) is a selective antagonist of post-synaptic alpha1-adrenoreceptors used in adult men to treat slow urination due to benign prostatic hyperplasia (BPH). 

Common side effects of Uroxatral include:

• dizziness,
• headache,
• tiredness,
• dizziness on standing (postural hypotension),
• and fainting.

Serious side effects of Uroxatral include:

• chest pain,
• priapism (persistent painful penile erection),
• liver injury,
• and floppy eye syndrome.

Drug interactions of Uroxatral include:

• ketoconazole,
• itraconazole,
• ritonavir,
• blood pressure reducing medications,
• and PDE-5 inhibitors. 

Uroxatral is not used by women; however, studies in animals have shown no evidence of fetal toxicity, even with exceedingly high doses of Uroxatral. Uroxatral is not prescribed for women and is unlikely to be used during pregnancy or while breastfeeding. 

• The most common side effects of alfuzosin are:
  • dizziness,
  • headache,
  • tiredness,
  • postural hypotension, and
  • fainting.
• These side effects occur in fewer than 1 per every 15 patients.
• As with other alpha blockers, postural hypotension (decreasing blood pressure upon standing, with or without dizziness) may develop within a few hours following ingestion of alfuzosin and can cause fainting.
• Prostate cancer and benign prostatic hyperplasia can co-exist. Therefore, patients being treated for benign prostatic hyperplasia should be evaluated to exclude the presence of prostate cancer.

Possible serious side effects include:

• chest pain,
• priapism (persistent painful penile erection),
• liver injury, and
• floppy eye syndrome.

Clinical Trials Experience

• Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
• The incidence of adverse reactions has been ascertained from 3 placebo-controlled clinical trials involving 1,608 men where daily doses of 10 and 15 mg alfuzosin were evaluated. In these 3 trials, 473 men received Uroxatral (alfuzosin HCl) 10 mg extended-release tablets. In these trials, 4% of patients taking Uroxatral (alfuzosin HCl) 10 mg extended-release tablets withdrew from the trial due to adverse reactions, compared with 3% in the placebo group.
• Table 1 summarizes adverse reactions that occurred in ≥2% of patients receiving Uroxatral, and at a higher incidence than that of the placebo group. In general, the adverse reactions seen in long-term use were similar in type and frequency to the events described below for the 3-month trials.

Table 1 : Adverse Reactions Occurring in ≥2% of Uroxatral-Treated Patients and More Frequently than with Placebo in 3-Month Placebo-Controlled Clinical Trials

The following adverse reactions, reported by between 1% and 2% of patients receiving Uroxatral and occurring more frequently than with placebo, are listed alphabetically by body system and by decreasing frequency within body system:

Body as a whole: pain

Gastrointestinal system: abdominal pain, dyspepsia, constipation, nausea

Reproductive system: impotence

Respiratory system: bronchitis, sinusitis, pharyngitis

Signs and Symptoms of Orthostasis in Clinical Trials: The adverse reactions related to orthostasis that occurred in the double-blind phase 3 trials with alfuzosin 10 mg are summarized in Table 2. Approximately 20% to 30% of patients in these trials were taking antihypertensive medication.

Table 2: Number (%) of Patients with Symptoms Possibly Associated with Orthostasis in 3-Month Placebo-Controlled Clinical Trials

Testing for blood pressure changes or orthostatic hypotension was conducted in three controlled studies.

• Decreased systolic blood pressure (≤90 mm Hg, with a decrease ≥20 mm Hg from baseline) was observed in none of the 674 placebo patients and 1 (0.2%) of the 469 Uroxatral patients.
• Decreased diastolic blood pressure (≤50 mm Hg, with a decrease ≥15 mm Hg from baseline) was observed in 3 (0.4%) of the placebo patients and in 4 (0.9%) of the Uroxatral patients.
• A positive orthostatic test (decrease in systolic blood pressure of ≥20 mm Hg upon standing from the supine position) was seen in 52 (7.7%) of placebo patients and in 31 (6.6%) of the Uroxatral patients.

Post-Marketing Experience

The following adverse reactions have been identified during post-approval use of Uroxatral. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

General disorders: edema

Cardiac disorders: tachycardia, chest pain, angina pectoris in patients with pre-existing coronary artery disease, atrial fibrillation

Gastrointestinal disorders: diarrhea

Hepatobiliary disorders: hepatocellular and cholestatic liver injury (including cases with jaundice leading to drug discontinuation)

Respiratory system disorders: rhinitis

Reproductive system disorders: priapism

Skin and subcutaneous tissue disorders: rash, pruritis, urticaria, angioedema, toxic epidermal necrolysis

Vascular disorders: flushing

Blood and lymphatic system disorders: thrombocytopenia

During cataract surgery, a variant of small pupil syndrome known as Intraoperative Floppy Iris Syndrome (IFIS) has been reported in some patients on or previously treated with alpha adrenergic antagonists.

CYP3A4 Inhibitors

Uroxatral is contraindicated for use with potent CYP3A4 inhibitors such as ketoconazole, itraconazole, or ritonavir, since alfuzosin blood levels are increased.

Alpha Adrenergic Antagonists

The pharmacokinetic and pharmacodynamic interactions between Uroxatral and other alpha adrenergic antagonists have not been determined. However, interactions may be expected, and Uroxatral should not be used in combination with other alpha adrenergic antagonists.

Antihypertensive Medication And Nitrates

There may be an increased risk of hypotension/postural hypotension and syncope when taking Uroxatral concomitantly with anti-hypertensive medication and nitrates.

PDE5 Inhibitors

Caution is advised when alpha adrenergic antagonists, including Uroxatral, are coadministered with PDE5 inhibitors. Alpha adrenergic antagonists and PDE5 inhibitors are both vasodilators that can lower blood pressure. Concomitant use of these two drug classes can potentially cause symptomatic hypotension.