Colestipol-induced hepatotoxicity.

A 65-year-old man with type IIa dyslipidemia who received flavored colestipol granules 2 scoops/day for 3 months developed asymptomatic hepatotoxicity. Several of his liver enzymes were elevated 10 times the upper limit of normal. One week after discontinuing colestipol, serum transaminases fell dramatically, with some returning to normal limits. Four weeks after colestipol was discontinued, all liver function tests were normal. Rechallenge was not attempted. Other potential causes of hepatocellular injury were evaluated. Bile acid-binding resins commonly are administered to treat type IIa dyslipidemia. Despite extensive use of the resins, significant elevations of transaminase levels are rare. Because the exact mechanism of bile acid resin-induced hepatotoxicity is unknown, high-risk patients may require liver function test monitoring and education on hepatotoxic side effects.

Development of an interdisciplinary, telephone-based care program.

An interdisciplinary, telephone-based care program at a Veterans Affairs medical center (VAMC) is described. Patients telephoning the Oklahoma City VAMC complained that they were transferred multiple times and that they had difficulty contacting their provider between scheduled visits. Some went to the walk-in urgent care clinic with nonurgent problems. The average waiting time in the clinic exceeded three hours. An interdisciplinary, telephone-based care program was begun in 1995 to allow efficient problem resolution over the telephone; provide clinical consultations, interventions, and referrals as necessary; and reduce use of the urgent care clinic for nonurgent problems. A team consisting of a patient service representative, a pharmacist, and a nurse was established to handle calls. Policies and procedures were designed to respond appropriately to patients' problems and document the telephone "visits." The pharmacist was given practice privileges, including prescribing authority. A questionnaire indicated patient satisfaction with the new service. Mean waiting times in the urgent care clinic were reduced to less than two hours, and an estimated annual net cost avoidance of $677,671 was achieved by the program's averting unnecessary visits to the urgent care clinic. An interdisciplinary, telephone-based care program at a VAMC successfully responded to patients' concerns, improved their access to care, and conserved urgent care resources.

Nitrovasodilator-induced relaxation and tolerance development in porcine vena cordis magna: dependence on intact endothelium.

1. Isolated segments of porcine vena cordis magna exhibited a reproducible contractile activity upon application of prostaglandin F2 alpha (PGF2 alpha) or KCl, that was independent of the presence of intact endothelium. Substance P (3 nM) elicited strictly endothelium-dependent relaxations amounting to 46.1 +/- 1.4% (n = 206) of contractions induced by 10 microM PGF2 alpha. 2. S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a compound that spontaneously liberates nitric oxide, concentration-dependently relaxed PGF2 alpha-precontracted (50 microM) venous segments. Tolerance induction (incubation with 100 microM SNAP for 30 min) within the same segments resulted in a 3 fold attenuation of this effect, which was not further reduced after additional preincubation with glyceryl trinitrate (GTN). Removal of endothelium or the presence of N omega-nitro-L-arginine methylester (L-NAME) significantly improved the potency of SNAP before and after tolerance induction. 3. Concentration-dependent relaxations induced by GTN in non-tolerant veins were similar in the presence and absence of endothelium but much more reduced in tolerant endothelium-denuded (75 fold) compared to intact (20 fold) segments. In contrast, the presence of L-NAME significantly improved GTN-activity solely in non-tolerant veins, which, therefore, also resulted in a more pronounced attenuation of activity due to tolerance induction (100 fold). Preincubation of intact veins with SNAP also reduced GTN-activity but to a lesser extent (10 fold). 4. The more delayed but much longer, and compared to GTN somewhat weaker, acting new nitrovasodilator N-(3-nitrato-pivaloyl)-1-cysteineethylester (SPM 3672) was more potent in denuded than intact non-tolerant venous segments. Induction of tolerance by GTN resulted in a 2 fold-attenuation of potency. This effect was increased to 15 fold in denuded veins but solely due to enhanced potency of SPM 3672 caused by removal of endothelium.5. These data demonstrate that intact endothelium of porcine vena cordis magna attenuates the relaxant potency of nitrovasodilators but also probably participates in vascular bioactivation of GTN.We suggest that the reduced potency of nitrovasodilators is due to endogenous production of nitricoxide, which may affect the soluble guanylate cyclase/cyclic GMP-system or inhibit nitrate bioactivation pathways.