Contraindications
Prior to administration of the first dose, the corrected QT (QTc) must be determined. If the QTc is greater than 440 msec (or 500 msec in patients with ventricular conduction abnormalities), dofetilide is contraindicated. If heart rate is less than 60 bpm, the uncorrected QT interval should be used. After each subsequent dose of dofetilide, QTc should be determined and dosing should be adjusted. If at any time after the second dose of dofetilide the QTc is greater than 500 msec (550 msec in patients with ventricular conduction abnormalities), dofetilide should be discontinued. Adverse effects
Torsades de pointes is the most serious side effect of dofetilide therapy. The incidence of torsades de pointes is 0.3-10.5% and is dose-related, with increased incidence associated with higher doses. The majority of episodes of torsades de pointes have occurred within the first three days of initial dosing. Patients should be hospitalized and monitored for the first three days after starting dofetilide.The risk of inducing torsades de pointes can be decreased by taking precautions when initiating therapy, such as hospitalizing individuals for a minimum of three days for serial creatinine measurement, continuous telemetry monitoring and availability of cardiac resuscitation. Pharmacology
Mechanism of action
Dofetilide works by selectively blocking the rapid component of the delayed rectifier outward potassium current (IKr).This causes the refractory period of atrial tissue to increase, hence its effectiveness in the treatment of atrial fibrillation and atrial flutter. Dofetilide does not affect dV/dTmax (the slope of the upstroke of phase 0 depolarization), conduction velocity, or the resting membrane potential.
Prune belly syndrome is a rare, genetic birth defect affecting about 1 in 40,000 births. About 97% of those affected are male. Prune belly syndrome is a congenital disorder of the urinary system, characterized by a triad of symptoms. The syndrome is named for the mass of wrinkled skin that is often (but not always) present on the abdomen of those with the disorder. Signs and symptoms
Prune-belly triad consists of signs such as: Cryptorchidism, abdominal wall defects and genitourinary defects:
A partial or complete lack of abdominal wall muscles. There may be wrinkly folds of skin covering the abdomen. Cryptorchidism (undescended testicles) in males
Urinary tract abnormality such as unusually large ureters, distended bladder, accumulation and backflow of urine from the bladder to the ureters and the kidneys (vesicoureteral reflux)Other signs include:

Frequent urinary tract infections due to the inability to properly expel urine. Ventricular septal defect
Malrotation of the gut
Club foot
Later in life, a common symptom is post-ejaculatory discomfort. Most likely a bladder spasm, it lasts about two hours. Musculoskeletal abnormalities include pectus excavatum, scoliosis, and congenital joint dislocations including the hip. Diagnosis of prune belly syndrome necessitates a thorough orthopaedic evaluation because of the high prevalence of associated musculoskeletal abnormalities. Pulmonary hypoplasia, pneumonia, and atelectasis involving lung lobes

Complications
Prune belly syndrome can result in distention and enlargement of internal organs such as the bladder and intestines. Surgery is often required but will not return the organs to a normal size.