Indication
Tadalafil is indicated in-
Erectile Dysfunction (ED)
Benign Prostatic Hyperplasia (BPH)
Both Erectile Dysfunction and signs and symptoms of Benign Prostatic Hyperplasia
Pharmacology
Tadalafil is a selective phosphodiesterase type 5 (PDE5) inhibitor. Inhibition of PDE5 increases cGMP in smooth muscle cells. cGMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum, causing penile erection. PDE5 also is present in smooth muscles of the prostate and bladder wall. Inhibiting PDE5 increases cGMP concentrations leading to relaxation of smooth muscle in the prostate and bladder. Smooth muscle relaxation may improve blood flow to the urinary tract and widen the opening of the bladder neck, resulting in improved voiding.
Dosage
Erectile Dysfunction: For most patients the recommended starting dose is 10 mg. The dose may be increased to 20 mg or decreased to 5 mg based on requirement. The maximum dosing frequency is once daily. Tadalafil is effective for up to 36 hours.Benign prostatic hyperplasia: The recommended dose is 5 mg taken at the same time every day.Combined Erectile Dysfunction and Benign prostatic hyperplasia: The recommended dose is 5 mg at the same time every day.
Interaction
May interact with Nitrates for example, Isosorbide, Nitroglycerin, Alpha adrenergic blockers, Antihypertensives, Alcohol, Antacids (magnesuim hydroxide/aluminum hydroxide), Ketoconazole, Ritonavir, Erythromycin, Itraconazole, Grapefruit juice, other HIV protease inhibitors, Rifampin, Carbamazepine, Phenytoin & Phenobarbital.
Contradiction
Use of Nitrates (for example, Nitroglycerine, Isosorbide): may increase hypotensive effects of Nitrates
Hypersensitivity reactions to Tadalafil
Side Effect
Headache, Dyspepsia, Back pain, Myalgia, Nasal pharyngitis, Nasal congestion are common side effects. Change in Color Vision, Sudden vision loss, Hearing loss, Stevens-Johnson Syndrome, Exfoliative dermatitis, Angina, Stroke, Myocardial infarction, Severe hypotension, Tachycardia may also occur rarely.
Pregnancy
Tadalafil has been assigned to pregnancy category B by the USFDA. Tadalafil is only recommended for use during pregnancy when benefit outweighs risk. There are no data on the excretion of Tadalafil in human milk. Caution should be used when administering tadalafil to nursing women.
Precaution
Angina, renal impairment, hepatic impairment, bleeding concomitant with Nitrates, Alpha Blockers, Alcohol, CYP3A4 Inhibitors (for example, Ritonavir, Ketoconazole, Itraconazole), other PDE5 inhibitors precaution should be taken in all these conditions.
Overdose
Storage
Keep in a dry place, away from light and heat. Keep out of the reach of children.