Antiulcer drug receives FDA approval

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  • The Chemical World This Week

    COMPUTATION RESOURCE SET IN MOTION Nominations for policy board posi-tions and for director of the National Resource for Computation in Chem-istry (NRCC) are starting to come in at Lawrence Berkeley Laboratory, following selection of LBL as the host organization for the new resource (C&EN, July 25, page 14). LBL hopes to pick a tentative policy board within a few weeks.

    That move is the first step in the procedures leading to operation of NRCC, which will begin after the new fiscal year starts on Oct. 1. It will be the U.S. chemical community's first major collective effort.

    Once nominations are completed, the LBL director will appoint the initial policy board. The board's first order of business will be to choose, along with the director of LBL, a di-rector for NRCC. The board then will work on setting up a users' organiza-tion.

    NRCC will use LBL's existing computer center. The NRCC staff will be capable of documenting, test-ing, and improving software; devel-oping new computational methods; and designing specialized hardware and software particularly suited to solving chemical problems. In addi-tion, it will conduct chemical and computational research.

    The new facility, says LBL deputy director Earl K. Hyde, "should make possible state-of-the-art computa-tions that were not possible before." Chemists from academic institutions as well as industrial and government laboratories will have access to the resource for basic research in chemi-cal kinetics, crystallography, macro-molecular science, nonnumerical methods, physical organic chemistry, quantum chemistry, statistical me-chanics, and energy systems.

    NRCC is the culmination of many studies and analyses over recent years. In 1970, a conference on com-putational support for theoretical chemistry was organized by the Na-tional Research Council's Committee on Computers in Chemistry, under the chairmanship of Dr. Peter G. Lykos of Illinois Institute of Tech-nology. That conference recom-mended establishment of a national computation center for quantum chemistry. In 1974, an NRC study group headed by Dr. Kenneth B. Wiberg of Yale University showed

    6 C&EN Aug. 22, 1977

    that computational needs extended beyond just theoretical chemistry. Its two-year study focused on the feasi-bility and desirability of a national computing center and recommended its establishment.

    The NRCC idea took a big step forward in 1975 with completion of a study by an NRC Planning Commit-tee for a National Resource for Com-putation in Chemistry, chaired by Dr. Jacob Bigeleisen of the University of Rochester. That report set out details of physical, management, and fund-ing needs for the facility. In 1976, with planning for NRCC under way and site selection in progress, the planning committee held a workshop that re-sulted in what amounts to a "hand-book" of research needs to aid the NRCC director and staff.

    NRCC is being funded jointly by the Energy Research & Development Administration and the National

    Antiulcer drug receives I Tagamet, a drug for treating duo-denal ulcers that was developed by SmithKline Corp., has just received Food & Drug Administration ap-proval for marketing. Stocking of pharmacies is to begin immediately, and the company expects that phy-sicians can begin prescribing the drug within several weeks. Tagamet has been available in the U.K. for nearly a year and is being marketed throughout the world.

    The drug belongs to a newly de-scribed class of compounds that act as antagonists of type-two histamine receptors. These receptors are found on the acid-secreting cells of the gas-trointestinal tract. The cells release acid when they bind histamine mol-ecules, contributing directly to ulcer formation.

    Tagamet interferes with this binding, thus blocking acid secretion. The drug, when administered orally or by injection, can heal duodenal ulcers rapidly, sometimes within weeks, according to SmithKline.

    Tagamet, known generically as cimetidine and chemically as iV-cyano-N/-methyl-iV//-[2-([(5-methyl-lif-imidazol-4-yl) methyljthio) eth-yl] guanidine, is a partial structural analog of histamine. Both contain imidazole rings, though the ring of the

    Science Foundation. The t\#o agen-cies held a competition to select the host institution, and LBL got the nod.

    Under the approved plan, NRCC will become a new division of LBL in order to maintain its national char-acter and its independence from other activities at the laboratory. It will have available to it LBL's computer center, which has a Control Data Corp. CDC 7600 computer coupled with two CDC 6000 series computers. Extensive outside user facilities and software are available.

    More or less in line with what was envisioned by NRC, the first-year budget for NRCC is $1.3 million, and it is expected to grow to $2.4 million by 1980. Of the $1.3 million, $440,000 is allocated for staff salaries and $400,000 for computing. The re-mainder is for workshops, equipment, communications, and the like. D

    DA approval new drug is methylated. Actually, Tagamet is one of a series of hista-mine analogs that SmithKline scien-tists have synthesized.

    It succeeds another candidate, metiamide, that was therapeutically effective but produced the unwanted side effect of reducing white blood cell

    SmithKline researchers examine hista-mine reaction products using TLC

  • production in some patients. Ta-gamet appears free of such side ef-fects, although at high doses it has produced liver and kidney damage in rats and dogs.

    Development of Tagamet culmi-nates a 13-year program, begun in SmithKline's U.K. laboratories, looking into the chemical and bio-logical activities of histamine. Prob-ably better known as the culprit in hay fever and other allergies, hista-mine is involved in many inflamma-tory reactions in the body.

    However, its involvement in caus-ing ulcers is undoubtedly most dev-astating. Four million Americans suffer from ulcers, and more than 6000 of them die each year from re-sulting complications. Medical costs for ulcer sufferers will reach nearly $1.5 billion this year, and less than 10% of that goes for purchasing drugs. Company spokesmen expect Ta-gamet to have a significant impact on treating gastrointestinal disease. D

    Changes in energy tax laws suggested by PEG The petrochemical industry, having won some and lost some when the House passed its omnibus energy bill, took its case to the Senate earlier this month. In testimony before the Sen-ate Finance Committee, which is considering the tax provisions of the energy legislation, the Petrochemical Energy Group said it "frankly doubted the effectiveness of using the tax system to accomplish energy policy objectives."

    Instead it advocates deregulation of oil and natural gas prices as the best way to promote conservation and conversion to other energy sources. However, if the tax system will be used to help achieve such goals, as seems most likely, PEG advocates a number of changes in the legislation as proposed by the President and as passed by the House.

    Speaking for PEG, 0. Pendleton Thomas, chairman of the board and chief executive officer of B. F. Good-rich, said that adherence to Admin-istration tax proposals would raise U.S. manufacturers' fuel and feed-stock costs above prices paid by for-eign competitors. This, he says, ac-tually would frustrate energy policy goals by increasing dependence on foreign energy sources. It also would negatively affect the petrochemical industry's up to now positive trade balance and inevitably raise con-sumer prices.

    To avoid such unwanted effects at least in part, Thomas first suggests that consumption taxes on oil and 1

    natural gas be imposed only where practical opportunity exists for con-version from or conservation of oil, natural gas, and natural gas liquids. He urges that the Senate go along with the House and exempt feedstock use and nonsubstitutable process use, such as use of natural gas in cracking furnaces to produce ethylene, from energy consumption taxes.

    Secondly, a House-passed provi-sion taxing natural gas liquids as part of the crude oil equalization tax

    Thomas: tax would raise costs

    should be changed to ensure that the tax is measured from each vendor's ceiling price, not from some arbitrary average price, which would not take into account widely varying prices caused by controls. However, Thomas also advocates subjecting natural gas liquids used for boiler fuels to the same consumption tax imposed on oil used for boiler fuels. If this is not done, he explains, a boiler fuel user could find it cheaper to use natural gas liquids than fuel oil, taking the nonsubstitutable liquids from farm-ers, petrochemicals, and other feed-stock and process users. D

    Sterility in workers halts fumigant output In the wake of reports of sterility among male plant workers involved in the manufacture of a widely used soil fumigant, l,2-dibromo-3-chloropro-pane, or DBCP, yet another firm has halted production of the substance.

    Dow Chemical stated on Aug. 11 that it has stopped production and sale of DBCP at its Magnolia, Ark.,

    plant. Sold by Dow under the trade-name Fumazone, the compound is used in agriculture to exterminate nematodes, grublike worms that de-stroy plant roots. Early this month Occidental Petroleum Corp. closed the agricultural chemical unit at its Lathrop, Calif., plant because of ste-rility among plant workers exposed to DBCP, which the firm sells under the name Oxy-DBCP-12. At the Lathrop plant, nine out of 23 workers exposed to the chemical had no sperm count at all after working in the plant from four to 15 years. Other workers who had worked for shorter periods of time also showed marked reduction in sperm count. Dow also has found re-duced sperm counts among workers at its Arkansas plant. California has banned the sale of the soil fumi-gant.

    The National Institute for Occu-pational Safety & Health is now in-vestigating plants that either make or process DBCP with any regularity. Shell Chemical is the only major producer of the compound other than Dow, and together they produce about 25 million to 30 million lb an-nually. Shell has stopped making the chemical for this season. Occidental buys the chemical from Dow, al-though the firm has produced it in the past.

    The Occupational Safety & Health Administration has warned some 80 firms that "appropriate action should be taken to protect employees from this potential hazard." The Envi-ronmental Protection Agency, which regulates pesticides, also is investi-gating DBCP, and an EPA spokes-person concedes that canceling its registration is being considered "as an option."

    Dr. Channing Meyer, chief of NIOSH's medical hazards program in Cincinnati, explains that although DBCP is the prime suspect in the Occidental plant incidents, other causes can't be ruled out. He notes, for example, that both the Occidental plant in California and the Dow plant in Arkansas produce other bromi-nated chemicals, such as ethylene dibromide, that also could be re-sponsible. Meyer believes, however, that other causes are unlikely, be-cause animal experiments conducted by Dow in the early 1960's showed testicular damage in rats exposed to DBCP.

    So far there is no federal workplace standard for exposure to DBCP, al-though Dow recommends that worker exposure be kept below 1 ppm. But even that may not be low enough. NIOSH's Meyer says that as far as the agency has been able to deter-mine, exposures in the Occidental plant averaged about 0.5 ppm. D

    Aug. 22, 1977C&EN 7

    Antiulcer drug receives FDA approval