Bismuth triple therapy: still a very important drug regimen for curing Helicobacter pylori infection.

Bismuth triple therapy (bismuth compound, metronidazole and tetracycline) is the oldest effective regimen to cure Helicobacter pylori infection. When tetracycline is replaced by amoxycillin the cure rate decreases. In 1990, it was the first-line regimen. However, the great number of pills in the rather complicated regimen, together with a relative high rate of side-effects, have stimulated the search for other regimens. In developed countries, it has now mainly been surpassed by the simpler, but much more expensive proton-pump inhibitor-based triple therapies. In many developing countries however, bismuth-based therapy is the only effective therapy patients can afford. Worldwide, this drug combination is therefore probably one of the most widely used regimens. The efficacy of bismuth triple therapy can be improved by adding acid suppressants (quadruple therapy), increasing treatment duration or increasing the total daily dose of metronidazole. The choice of the bismuth compound and the total daily dose of tetracycline seem less important. Treatment can be shorter (7 days) in areas with a low rate of metronidazole resistance or when acid inhibition is added. Bismuth is usually given four times daily; tetracycline is usually given 500 mg q.i.d. in a 7- or 10-day treatment, but this can probably be reduced to 250 mg q.i.d. in a 14-day regimen. A higher total daily dose of metronidazole increases the cure rate but also gives more side-effects. A daily dose of 1000-1200 mg metronidazole in three or four divided doses for one week suffices in areas with a low rate of metronidazole resistance. In areas with a higher rate of resistance one can either increase the treatment duration to 10-14 days or increase the daily dose of metronidazole to 1500-1600 mg and leave the treatment duration at 7 days.