From the Research
Diltiazem (Cardizem) Controlled Release (CR) vs Extended Release (ER)
- The terms "controlled release" and "extended release" are often used interchangeably to describe medications that release their active ingredients over an extended period, rather than all at once 1, 2.
- Studies have compared the bioavailability and pharmacokinetics of different diltiazem formulations, including controlled release and extended release products 1, 2, 3.
- One study found that a new extended release diltiazem formulation (Tiazac) had significantly higher plasma concentrations and a longer duration of action compared to two other marketed extended release products, including Cardizem CD 1.
- Another study compared the pharmacokinetics of two new sustained-release products of diltiazem (Dilapress 120 mg and Dilapress 240 mg) with several other diltiazem SR formulations, including Cardizem Retard, Cardizem SR, and Cardizem CD 2.
- A study that evaluated the conversion from sustained-release to immediate-release calcium entry blockers, including diltiazem, found that blood pressure was controlled in 94% of patients switched from diltiazem CD to immediate-release diltiazem 4.
- The antianginal efficacy and safety of controlled-delivery diltiazem QD versus an equivalent dose of immediate-release diltiazem TID were assessed in two multicenter, randomized, double-blind, placebo-controlled trials, which found that the controlled-delivery formulation was safe and effective for the treatment of patients with chronic stable angina 5.
- A comparative study of the steady-state pharmacokinetics of immediate-release and controlled-release diltiazem tablets found that the controlled-release formulation maintained plasma concentrations above the minimum therapeutic plasma concentration throughout the full 24 hours 3.
Key Findings
- Diltiazem controlled release and extended release formulations have similar goals, which are to release the active ingredient over an extended period 1, 2.
- Different diltiazem formulations, including controlled release and extended release products, may have varying pharmacokinetic profiles 1, 2, 3.
- The choice of diltiazem formulation may depend on individual patient needs and responses to treatment 4, 5.