Preliminary bioavailability study on protacine: a new, non-steroidal anti-inflammatory agent.

Time versus concentration curves of unchanged protacine were measured in the blood of 5 healthy volunteers by high pressure liquid chromatography after a single oral dose of 4 capsules (600 mg). These curves showed a maximum at 8 hours after administration, with an absorption half-life of 3.4 hours, and were interpreted according to the two-compartment open model with invasion. The elimination half-life was found to be 10 hours. This may allow a maintenance treatment, where necessary, with 1 capsule (150 mg) of protacine twice daily and strongly suggests that, apart from acute cases, protacine would be particularly well suited for long-term treatment.

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.

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.

Double-blind clinical evaluation of a new anti-inflammatory drug, protacine, versus indomethacin.

A double-blind clinical trial was carried out in 69 rheumatic in-patients to compare the efficacy and tolerance of a new, non-steroidal anti-inflammatory agent, protacine, with that of indomethacin. Patients received either 150 mg protacine or 50 mg indomethacin 3-times daily for 21 days. The time course of symptoms was recorded by semiquantitative scoring, as were side-effects. Uropepsinogen excretion, occult blood in faeces and standard physiological parameters were also monitored. Protacine globally decreased symptom scores by 58.5% and indomethacin by 24.3% (p less than 0.001). The computed time to reduce symptom scores by 50% was 17.2 days with protacine as compared to 39.2 days with indomethacin (p less than 0.001). Physiological parameters did not change, except white blood cells which decreased after protacine (each subject however, remaining well within the physiological range) and erythrocyte sedimentation rate, which decreased in both groups. Uropepsinogen excretion increased by 70% after protacine, and threefold after indomethacin (p less than 0.001). Occult blood search was positive in 1 patient receiving protacine, while 2 who were already positive before receiving protacine became negative during the treatment. Four patients taking indomethacin were found to be positive, 1 showing melaena. The one who was already positive before treatment showed increasing severity of occult bleeding during indomethacin administration. Frequency and severity of side-effects were significantly less with protacine (p = 0.004). In conclusion, protacine showed analgesic and anti-inflammatory actions significantly more potent and rapid than those of indomethacin, with significantly fewer and less severe side-effects.

Double-blind clinical comparison between a gastrin-receptor antagonist, proglumide, and a histamine H2-blocker, cimetidine.

A double-blind trial was carried out in 30 patients with peptic ulcers to assess the effects of treatment with a gastrin-receptor antagonist, proglumide, compared with a histamine H2-blocker, cimetidine. Patients received either 1200 mg proglumide or 1200 mg cimetidine per day for 28 days. The results showed that both drugs significantly reduced clinical symptoms and gastric secretion. In patients treated with cimetidine there was a significant increase in blood gastrin levels and marked hypertrophy and hyperplasia of the antral mucosa was observed in almost all patients. No such changes were found in the patients treated with proglumide.