A retrospective cohort study exploring diltiazem as a pharmaco-enhancer for tacrolimus, in a post-heart transplant setting.

BACKGROUND: A significant proportion of heart transplant-associated expenditure are attributable to immunosuppressants. Post-transplant hypertension adds to the pill burden and subsequent costs. In this study, we describe the effect of diltiazem-the antihypertensive and pharmaco-enhancer-on reducing the required oral dose of tacrolimus. METHODS: We included 17 recipients who had successfully undergone heart transplants but later developed post-transplant hypertension and were treated with diltiazem. Serum trough levels of the immunosuppressant tacrolimus were measured every 2 weeks. Required doses before and after the introduction of diltiazem were compared. Patients were assessed at each follow-up visit for any evidence of toxicity. Medication-related expenditure was estimated based on government-mandated standardized retail price. RESULTS: The power of the study was 98.92% at α = 0.05. The mean tacrolimus dose required prior to initiation of diltiazem was 5.85 ± 1.55 mg. After initiating diltiazem, the mean required doses reduced to 2.88 ± 1.24 mg (p < .0001). Relatively, the required doses reduced by 52.4 ± 10.9%-independently of age, sex, and dose of diltiazem. Medication-related monthly expenditure reduced by 50.3 ± 10.4%. No patient demonstrated evidence of toxicity. CONCLUSIONS: Concomitant use of diltiazem and tacrolimus can safely, effectively, and predictably reduce the required dose of tacrolimus and significantly reduce corresponding costs.

Hybrid procedure.

With increase in aging population and increased prevalance of coronary risk factors including diabetes mellitus, more people with multivessel coronary artery disease are diagnosed. Many of these patients undergo coronary angioplasty or bypass graft surgery (CABG). Hybrid coronary revascularisation may be preferred in multivessel CAD patients with technical limitations to PCI or CABG and in whom minimising invasiveness of CABG is preferred. Our case highlights patient selection and procedure for this new modality of coronary artery disease treatment.