BOEHRINGER INGELHEIM I.V. PERSANTINE APPROVED

BOEHRINGER INGELHEIM I.V. PERSANTINE APPROVED as an alternative to exercise in thallium myocardial perfusion imaging in patients who cannot exercise. The NDA for I.V. Persantine (dipyridamole) was approved by FDA on Dec. 13 after almost three years of review. B-I licenses I.V. Persantine from DuPont Pharmaceuticals. The product will be available in 2 ml ampules. According to approved labeling, the injection form of the coronary vasodilator is indicated "as an alternative to exercise in thallium myocardial perfusion imaging for the evaluation of coronary artery disease in patients who cannot exercise adequately." In a study of I.V. Persantine, "a subset of patients who had exercise thallium imaging as well as Persantine thallium imaging, sensitivity and specificity of the two tests was almost identical," according to labeling. Serious adverse reactions with I.V. Persantine "have included fatal and non-fatal myocardial infarction, ventricular fibrillation, symptomatic ventricular tachychardia, transient cerebral ischemia, and bronchospasm." The incidence of these adverse events in a large study was very small, 0.3%, or 10 out of 3,911 patients. In December 1986, oral Persantine was approved as an adjunct to coumarin anticoagulants in the prevention of postoperative thromboembolic complications of cardiac valve replacement. This indication gave the drug three years of marketing exclusivity. Under FDA's DESI review, dipyridamole was determined to be ineffective for the original indication of treating angina. Based on that determination, FDA was going to initiate withdrawal proceedings for the brandname and generic products from the market. However, the products stayed on the market because the withdrawal procedures never occurred. B-I received the new indication for cardiac valve replacement and decided not to defend the angina indication. Recently, several generic versions received approval for the cardiac valve indication. DuPont, which now operates as the joint venture with Merck, has several other products awaiting FDA approval. The closest is probably Cardiolite, a technetium-based myocardial imaging agent. In November 1989, an FDA advisory committee recommended approval for Cardiolite in imaging patients with suspected myocardial infarction. Squibb's technetium-based agent Cardiotec was approved on Dec. 21 (see In Brief). DuPont's Thallium-201 is the standard for cardiac imaging agents. DuPont is also expecting approval for Cardene I.V. (nicardipine), which was recommended by an advisory committee as second-line therapy for hypertension.