Indication
Silodosin, a selective alpha-1 adrenergic receptor antagonist, is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). Silodosin is not indicated for the treatment of hypertension.
Highly effective for the treatment of Benign Prostatic Hyperplasia.
Highest uroselectivity to alpha-1 adrenergic receptor.
Effective treatment option for BPH who are not responding to Tamsulosin.
Dose not cause Orthostatic hypotension.
Convenient once-daily dosing.
Pharmacology
Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors, which are located in the human prostate, bladder base, bladder neck, prostatic capsule and prostatic urethra. Blockade of these alpha-1 adrenoreceptors can cause smooth muscle in these tissues to relax, resulting in an improvement in urine flow and a reduction in BPH symptoms.
Dosage
The recommended dose is Silodosin 8 mg orally once daily with a meal.?ÿ4 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.
Contradiction
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 Effect
Most common adverse reactions are retrograde ejaculation, dizziness, diarrhea, orthostatic hypotension, headache, nasopharyngitis and nasal congestion.
Pregnancy
Pregnancy Category B. Silodosin is not indicated for use in women. An embryo/fetal study in rabbits showed decreased maternal body weight at 200 mg/kg/day (approximately 13-25 times the maximum recommended human exposure or MRHE of Silodosin via AUC). No statistically significant teratogenicity was observed at this dose. Silodosin was not teratogenic when administered to pregnant rats during organogenesis at 1000 mg/kg/day (estimated to be approximately 20 times the MRHE). No maternal or fetal effects were observed at this dose. Rats and rabbits do not produce glucuronidated Silodosin, which is present in human serum at approximately 4 times the level of circulating Silodosin and which has similar pharmacological activity to Silodosin. No effects on physical or behavioral development of offspring were observed when rats were treated during pregnancy and lactation at up to 300 mg/kg/day.
Precaution
Postural hypotension with or without symptoms (e.g. dizziness) may develop when beginning Silodosin treatment. Silodosin should not be used in combination with other alpha-blocker. Inform patients planning cataract surgery to notify their ophthalmologist that they are taking Silodosin because of the possibility of Intraoperative Floppy Iris Syndrome (IFIS)
Overdose
Silodosin was evaluated at doses of up to 48 mg/day in healthy male subjects. The dose-limiting adverse event was postural hypotension. Should overdose of Silodosin lead to hypotension, support of the cardiovascular system is of first importance. Restoration of blood pressure and normalization of heart rate may be accomplished by maintaining the patient in the supine position. If this measure is inadequate, administration of intravenous fluid should be considered. If necessary, vasopressors could be used, and renal function should be monitored and supported as needed. Dialysis is unlikely to be of significant benefit since Silodosin is highly (97%) protein bound.
Storage
Store at below 30?øC in a dry place protected from light. Keep out of reach of Children.