ABBOTT HYTRIN (TERAZOSIN) BPH INDICATION APPROVED SEPT. 29

ABBOTT HYTRIN (TERAZOSIN) BPH INDICATION APPROVED SEPT. 29 for relief of urinary symptoms associated with benign prostatic hyperplasia. "There is rapid response, with approximately 70% of patients experiencing an increase in urinary flow and improvement in symptoms of BPH when treated with Hytrin," approved labeling states. Abbott said Sept. 30 that the drug "can begin to reduce... symptoms within two weeks." Hytrin, a selective alpha-blocker, has been marketed as an antihypertensive agent since 1987. FDA's Endocrinologic & Metabolic Drugs advisory committee unanimously recommended approval of Hytrin for the relief of BPH symptoms in March ("The Pink Sheet," March 8, p. 3). Abbott submitted the NDA (20-223) for Hytrin for BPH on Dec. 20, 1991. FDA also granted approval of a supplemental NDA (19-057/S-006) to Abbott's original NDA, which relates to the addition of BPH information to currently approved labeling. Labeling explains that "improvement in urine flow rates following administration of terazosin is related to relaxation of smooth muscle produced by blockade of alpha-1 adrenoceptors in the bladder neck and prostate. Terazosin is able to reduce bladder outlet obstruction without affecting bladder contractility," labeling adds. Hytrin will compete against Merck's 5-alpha reductase inhibitor Proscar (finas teride). Determining the eventual best treatment regimen between the two, however, may have to await the outcome of a combo trial under way at the Department of Veterans Affairs. Hytrin acts by relaxing the smooth muscle of the prostate and bladder neck. Proscar has been shown to reduce the actual volume of the prostate. Proscar labeling, however, notes that symptom relief may not be apparent for up to one year. The V-A study is ongoing in 1,200-BPH symptomatic men at 30 V- A medical centers. The one-year study is due to conclude in December. Participants in the study are being treated with one of four therapies: Proscar, Hytrin, Proscar plus Hytrin or placebo. Merck, Abbott and the V-A Medical Research Service are funding the study. Abbott has created a "Hytrin Free Start" program for physicians to provide BPH patients with up to a 21-day supply of free samples, patient information brochures on how to properly start and maintain Hytrin therapy, and a BPH "answer book." Hytrin costs approximately 95 " per day direct price, according to Medi- Span's prescription drug pricing guide. Proscar lists for $1.45 per day. Merck is running a "Patient Support Program" for Proscar. In the Merck program, pharmacists provided patients with certificates for the initial 30-day supply of Proscar. After six months of therapy, Proscar patients are given another one month supply. Thereafter, patients are given a certificate for a free month of Proscar after each 12 months of additional therapy. In clinical trials of Hytrin, "asthenia, postural hypotension, dizziness, somnolence, nasal congestion/rhinitis, and impotence were significantly more common in patients receiving terazosin than in patients receiving placebo," labeling states. However, "urinary tract infection was significantly lower" in terazosin patients than placebo. The incidence rate of hypotensive adverse events "has shown that risk is greatest during the initial seven days of treatment," labeling states, "but continues at all time intervals." Hytrin labeling recommends 1 mg at bedtime as the "starting dose for all patients." Labeling cautions that close monitoring of patients should accompany the initial administration to minimize the risk of severe hypotensive response." Doses should be increased to 2 mg, 5 mg or 10 mg once daily to improve symptoms and/or flow rates. Doses of 10 mg once daily are required for clinical response "with four to six weeks at the 10 mg level required to assess beneficial response," labeling states. FDA's approval letter for Hytrin reminds Abbott that the company should consult with the Division of Biopharmaceutics regarding the protocol for obtaining pharmacokinetic/ pharmacodynamic data in the target population for a proposed Phase IV safety and efficacy extension study. FDA described the Phase IV studies in an Aug. 11 letter to Abbott.