Low-dose lansoprazole and clarithromycin plus metronidazole vs. full-dose lansoprazole and clarithromycin plus amoxicillin for eradication of Helicobacter pylori infection.

AIM: To compare, in a randomized controlled trial, the efficacy and tolerability of two 1-week triple therapies for Helicobacter pylori eradication. METHODS: One hundred and thirty-four consecutive patients with non-ulcer dyspepsia and H. pylori infection were randomized to receive lansoprazole 30 mg once daily, clarithromycin 250 mg twice daily, and metronidazole 500 mg twice daily (LCM group), or lansoprazole 30 mg twice daily, clarithromycin 500 mg twice daily, and amoxicillin 1000 mg twice daily (LCA group). H. pylori status was assessed by rapid urease test, histology and 13C-urea breath test before and after therapy. RESULTS: At 3 months, H. pylori eradication (intention- to-treat/per protocol analysis) was 92.4%/93.8% in the LCM group and 83.1%/85.7% in the LCA group (P=N.S.). Side-effects were more frequently reported in the LCA group (37.9%) than in the LCM group (19.7%) (P < 0.05). CONCLUSIONS: In this open, randomized controlled trial, eradication of H. pylori by low-dose lansoprazole and clarithromycin plus metronidazole was higher with significantly less side-effects than by full-dose lansoprazole and clarithromycin plus amoxicillin. This finding may be related to the stronger synergism of clarithromycin plus metronidazole, even at lower doses, than of clarithromycin plus amoxicillin. Considering the lower cost as well, LCM should be preferred to LCA in the eradication of H. pylori.

Toremifene in postmenopausal breast cancer. Efficacy, safety and cost.

Toremifene is a chlorinated tamoxifen analogue that is indicated for the treatment of postmenopausal hormone-dependent breast cancer. It competes with estradiol for estrogen receptors and has growth-inhibitory effects on MCF-7 breast cancer cells. At concentrations < 10(-6) mol/L, this growth inhibition can be reversed by estradiol, but at higher concentrations toremifene is cytotoxic. In dimethylbenzanthracene (DMBA)-induced mammary cancer in rats, toremifene has been shown to decrease the number of new tumours and to inhibit the growth of existing tumours. Toremifene causes growth inhibition by suppressing mitosis and inducing apoptosis. The mechanism by which these events occur may involve the induction of transforming growth factor-beta 1 and inhibition of insulin-like growth factor-1 (mecasermin). Toremifene is primarily an antiestrogen, but it has some estrogen agonist properties in postmenopausal women. The latter are reflected by the fall in luteinising hormone and follicle-stimulating hormone levels and the rise in sex hormone-binding globulin levels that are associated with its use in most women. After estrogen priming, toremifene 68mg administered orally has been found to exert a similar antiestrogenic effect on the vaginal epithelium in postmenopausal women as tamoxifen 60mg. The half-life of toremifene in plasma is 5 days, and the drug is > 99% bound to plasma proteins. The main metabolites of toremifene are N-demethyl-toremifene and deaminohydroxy-toremifene. Altered liver, but not kidney, function affects the pharmacokinetics of toremifene. Toremifene 60mg daily is as effective as tamoxifen 20mg daily in the treatment of postmenopausal hormone-dependent breast cancer, producing a response in about 50% of patients. Soft tissue and visceral metastases respond better to toremifene than bone metastases. Most of the adverse effects of toremifene are related to its activity at estrogen receptors and include hot flashes, vaginal discharge and nausea. Although toremifene decreases antithrombin III levels slightly, the incidence of thromboembolic complications is low. Thus far, no carcinogenic effects have been noted in humans, and preclinical data are mostly reassuring. Toremifene has favourable effects on serum lipids, and thus has potential in preventing coronary heart disease. Although toremifene is somewhat more expensive to use than tamoxifen, toremifene is an effective and well tolerated alternative to tamoxifen in the treatment of postmenopausal women with hormone-dependent breast cancer. No formal pharmacoeconomic comparisons of toremifene and tamoxifen have yet been published. Toremifene is potentially safer than tamoxifen in relation to carcinogenic effects and effects on serum lipids.