AARP PRICING ZENITH's DIAZEPAM TO ASSN. MEMBERS AT $9.95, $13.95, $22.95 FOR 2, 5, 10 MG 100s; FDA APPROVES P-D, MYLAN, ZENITH VERSIONS OF VALIUM SEPT. 4

The American Assn. of Retired Persons' (AARP) Pharmacy Service is pricing Zenith's diazepam tablets to assn. members at $9.95 for 2 mg 100s, $13.95 for 5 mg 100s, and $22.95 for 10 mg 100s. AARP formerly sold Roche's Valium in the same respective dosages and quantities for AARP ordered the Zenith product Sept. 5, one day after HHS at a press conference announced FDA approval of three generic versions of Valium. The assn. expects 60-day quantities to By contrast Blue Cross/Blue Shield of Michigan has delayed setting reimbursement limits for diazepam Rxs. Although the health insurance plan said it expects to set cost ceilings for the tranquilizer, it will first as a matter of policy examine bioequivalence test reports on which FDA based its approval. Parke-Davis (P-D) and Mylan, as well as Zenith, received FDA approval for generic diazepam Sept. 4. P-D said its version will carry a retail price 30-50% below Valium. Mylan said its product would be priced to pharmacists with a 50% discount. All three firms were anticipating word of approval from FDA and began shipments immediately after an HHS press conference announced availability of the generic tranquilizers. A company spokesman said P-D expected its diazepam product to reach retail shelves early in the week of Sept. 9. The new versions of the tranquilizer will be available in the same dosage strengths as Valium tablets: 2, 5, and 10 mg. The generic approvals end a 22-year monopoly for Valium, which Roche introduced in 1963. According to a Roche spokesman, the product's price structure will remain unchanged in the According to summary bases of approval prepared by FDA, in vivo triple crossover studies comparing Valium, the test drug and oral solution showed the three generics to be bioequivalent to Roche's product. P-D and Mylan performed the triple crossover studies in each of the three dosages. Zenith conducted the bioequivalence study in the 10 mg strength only and received a waiver for studies in the 2 and 5 mg concentrations. Roche maintained in a petition to FDA that blood level tests were insufficient to prove bioequivalence. The company proposed in February, just before its Valium patent expired, that FDA's diazepam bioavailability guidelines include electroencephalography at the site of action in the brain. FDA responded in a July letter that "there is no basis for rejection of the use of blood level testing to determine bioequivalence or therapeutic equivalence of diazepam products" ("The Pink Sheet" July 15, T&G-2). In response to the petition, FDA did agree to modify its bioequivalence testing guidelines to provide for testing in additional buffer media and for added sampling times. Roche submitted a second petition in mid-July asking for "clear official standards" for generic diazepam products ("The Pink Sheet" July 22, T&G-4). The Valium mfr. had argued that its own brain level studies showed that two generic versions of diazepam, made in Italy and in Canada, were shown to be inequivalent to Valium even though standard blood level studies found the products to be bioequivalent. At the HHS press conference, FDA Generic Drugs Div. Director Marvin Seife, MD, maintained that "state of the art" bioequivalence tests demonstrated the P-D, Mylan, and Zenith products to be "bioequivalent and therapeutically equivalent." Seife added that the generic diazepam tested by Roche involved a "strange product." By approving P-D's, Zenith's, and Mylan's versions of diazepam, FDA has made it difficult to raise a public debate over the quality of the generic products. P-D is a fellow Pharmaceutical Mfrs. Assn. member; Zenith's President James Leonard formerly was president of Roche Products in Puerto Rico, where Valium is manufactured; and Mylan is a highly reputable generic mfr. Valium is conspicuously distinguishable from the other three products by the "V"-shaped cutout in the center of the round tablet. When Roche introduced its new tablet design in early 1984 in anticipation of generic copies, the company said Valium is the only pharmaceutical on the market with a cutout. Roche also markets a 5 mg/ml injectable form of diazepam to hospitals. Zenith appears to be positioned at the crest of the new wave of post-1962 ANDA approvals, with marketing rights to a generic propranolol ("The Pink Sheet" Aug. 12, T&G-1) and diazepam. Like P-D, Zenith said its diazepam will be priced at retail 30-50% below Valium. A Zenith spokesman said the firm hopes to capture 50% of the generic diazepam market, which, he speculated, within 12 months will represent 50% of the total diazepam market.