Pharmacodynamics Hypertension: In short term, double blind, placebo-controlled clinical trials Tiazac demonstrated dose-related antihypertensive response among patients with mild to moderate hypertension. Dosage Hypertension: Dosages must be adjusted to each patient needs, starting with 180 mg or 240 mg once daily. At peak, hours after dosing, exercise tolerance times diltiazem kop relative to baseline were statistically significantly increased by 13, 38,64,55 and 42 seconds for placebo and 120 mg, 240 mg, 360 mg, and 540 mg Tiazac treated patients, respectively. The US has expressed dismay after court in Iran jailed an Iranian American journalist, Roxana Saberi, for eight years on spying charges. Write Check with your health care diltiazem before stopping Other drugs posing risk with erythromycin, Ray said, include the antibiotic clarithromycin, sold under the Biaxin brand.