Pharmacokinetic approach to proglumide long-term activity.

In order to explain the long-term therapeutic activity of (+/-)-4-benzamide-N,-di-n-propylglutaramic acid (proglumide, Milid) a pharmacokinetic study was carried out in rats by three administration routes. As a result, experimental data could have been fitted to a tri- or tetra-exponential equation, with terminal half-life of about 24 h. Since human pharmacokinetics was found to be rather similar to that in rats, it can be extrapolated that steady state plasma level of drug during therapeutic dosage regimen should range around 60% of peak level of single administration.

Studies on the mechanism of action of protacine (CR 604), a new non-steroidal anti-inflammatory agent.

3'-(4-[2-(1-P-Chlorobenzoyl-5-methoxy-2-methyl-indol-3-yl-acetoxy)-ethyl]-piperazin-1-yl)propyl-4-benzamido-N,N-dipropyl-glutaramate(+/-)dimaleate (protacine, CR 604), a new non-steroidal compound active on experimental inflammation, in vitro inhibits prostaglandin synthesis from arachidonic acid and platelet aggregation. When administered p.o., it prevents ex vivo platelet aggregation and in vivo arachidonate-induced thrombosis in rabbits. The cAMP levels of rat leucocytes are significantly reduced after treatment in vivo with protacine, even under maximum PGE-mediated stimulation. These effects, the inhibition of the proteolytic activity of trypsin and the fibrinolytic properties evidenced on recalcified plasma clots, contribute to explain the anti-inflammatory activity of protacine.

Pharmacological study of a new non-steroidal anti-inflammatory drug: protacine (CR 604).

The pharmacological activities of 3'-(4-[2-(1-p-chlorobenzoyl-5-methoxy-2-methyl-indol-3-yl-acetoxy)-ethyl]-piperazin-1-yl)propyl-4-benzamido-N,N-dipropylglutaramate(+/-)dimaleate (protacine, CR 604), a new indolyl derivative with strong anti-inflammatory, analgesic and antipyretic activities, are described. The dose-dependent activity of protacine on inflammation has been shown both in short-term experiments, like the hind paw edema induced by carrageenin and several other irritants, and long-term tests, like the aminoacetonitrile-induced osteolathyrism, the adjuvant-induced arthritis and the cotton pellet-induced granuloma. The analgesic activity of the drug has been evidenced in the phenylquinone-induced writhing and the Randall-Selitto tests, and the antipyretic effects in the yeast-induced hyperthermia in rats. Other general pharmacological effects have been studied, too. Contrarily to several other anti-inflammatory drugs, including indometacin, showing advers effects at doses which are in the same range of those active on experimental inflammation, protacine shows these effects to a minor degree and at doses which are much larger than those pharmacologically active. The therapeutic index of protacine therefore is superior to that of other anti-inflammatory drugs.