Generic

Silodosin

Indications

Silodosin is a selective alpha-1 adrenergic receptor antagonist that is used to treat the symptoms of benign prostatic hyperplasia (BPH). The use of silodosin for the treatment of hypertension is not recommended.

• Treatment for Benign Prostatic Hyperplasia is extremely effective.
• The alpha-1 adrenergic receptor has the highest uroselectivity.
• Tamsulosin is an effective therapy choice for BPH patients who are not responding to it.
• Orthostatic hypotension is not a side effect.
• Dosing is done once a day, which is quite convenient.

Pharmacology

Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors found in the prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra in humans. When these alpha-1 adrenoreceptors are blocked, the smooth muscle in these tissues relaxes, improving urine flow and alleviating BPH symptoms.

Dosage & Administration

The recommended dose is Silodosin 8 mg orally once daily with a meal. 4 mg capsules taken orally once daily with a meal for those with moderate renal impairment (CrCl 30-50 mL/min).

Interaction

Strong P-glycoprotein inhibitors (e.g., cyclosporine): Co-administration may increase plasma Silodosin concentration. Concomitant use of PDE5 inhibitors with alpha-blockers including Silodosin can potentially cause symptomatic hypotension.

Contraindications

Patients with severe renal & hepatic impairment, concomitant administration with strong Cytochrome P450 3A4 (CYP3A4) inhibitors (e.g., ketoconazole, clarithromycin, itraconazole, ritonavir) and patients with a history of hypersensitivity to Silodosin.

Side Effects

Most common adverse reactions are retrograde ejaculation, dizziness, diarrhea, orthostatic hypotension, headache, nasopharyngitis and nasal congestion.

Pregnancy & Lactation

Pregnancy Classification B. Silodosin is not recommended for women. At 200 mg/kg/day, a rabbit embryo/fetal research revealed a drop in mother body weight (approximately 13-25 times the maximum recommended human exposure or MRHE of Silodosin via AUC). At this dose, no statistically significant teratogenicity was seen.

Precautions & Warnings

When starting Silodosin medication, postural hypotension with or without symptoms (e.g. dizziness) can occur. Silodosin should never be taken with another alpha-blocker. Patients who are having cataract surgery should tell their ophthalmologist if they are taking Silodosin, as this can cause Intraoperative Floppy Iris Syndrome (IFIS).

Therapeutic Class

BPH/ Urinary retention/ Urinary incontinence

Storage Conditions

Do not store at temperatures above 30°C. Keep out of children’s reach.

Pharmaceutical Name

Aristopharma Ltd.