Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Piroximone, dobutamine and nitroprusside: comparative effects on haemodynamics in patients with congestive heart failure

Four intravenous doses of piroximone, an imidazolone derivative, were administered to 12 patients with congestive heart failure to produce a four-point dose-response curve. The haemodynamic effects were compared with those of dobutamine and nitroprusside, the substances being given sequentially and in randomized order. Piroximone and dobutamine significantly and similarly increased cardiac index (CI) and stroke volume index (SVI). Nitroprusside produced no such effect. By contrast, piroximone and nitroprusside significantly and similarly decreased mean pulmonary artery pressure (MPAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAP) and pulmonary vascular resistance (PVR), while such changes were not seen following dobutamine. Direct comparisons between the agents were made at doses that lowered systemic vascular resistance (SVR) to the same extent. The major difference between dobutamine and piroximone was an apparent additional vasodilator activity displayed by piroximone as demonstrated by a significantly greater decrease in MPAP, PCWP and RAP for a matched reduction in SVR and a similar increase in CI. The major difference between nitroprusside and piroximone was the significantly higher increase in CI and SVI elicited by piroximone for a matched reduction in SVR and a similar decrease in PCWP and RAP. The changes in loading conditions being equivalent, the higher increase in CI is likely to be accounted for by a direct inotropic activity.

Long-term treatment with piroximone in patients with chronic heart failure

The safety and efficacy of long-term oral piroximone therapy was assessed in 12 patients with chronic heart failure. Of these 12 patients, two died suddenly, and a further two were withdrawn because of worsening heart failure within 6 months while 8 completed the 1-year follow-up period. In 7 of these 8 patients, clinical evaluations showed sustained benefit, as demonstrated by significant increases in exercise tolerance. The remaining patient experienced a recurrence of severe heart failure at the end of follow-up. Twenty-four hour ambulatory electrocardiograms were compared in 9 patients before and during piroximone therapy. Aggravation of existing arrhythmias was observed in 3 patients, an amelioration in one with no change in the remaining 5. In the 5 patients in whom the hemodynamic effects of a single oral dose of 25 mg of piroximone were studied, the first dose resulted in a 20% increase in mean cardiac index and a 30% decrease in mean pulmonary capillary wedge pressure. This responsiveness to single-dose administration was maintained after 1-year follow-up. Likewise, comparison of the hemodynamic effects of four intravenous doses of piroximone revealed no significant difference in the response (n = 7), although the effects tended to be less marked at the end of follow-up. The present results suggesting that piroximone is effective and safe as adjunctive therapy in the management of patients with chronic heart failure will need to be confirmed in longer controlled trials.

Cardiovascular profile of UDCG 115 BS-pimobendane and reversibility of catecholamine subsensitivity in severe congestive heart failure secondary to idiopathic dilated cardiomyopathy

The pyridazoline derivative UDCG 115 BS (pimobendane) is a new, noncatecholamine, nonglycoside inotropic compound with potent vasodilative properties which exerts its stimulatory myocardial effect by increasing the Ca2+ affinity of cardiac contractile proteins and thus improving Ca2+ utilization. The aim of this study was to characterize and quantify the hemodynamic profile of oral UDCG 115 BS in 25 patients suffering from idiopathic congestive cardiomyopathy (NYHA III) and compare these effects with the action of the beta 1-receptor agonist dobutamine. UDCG 115 BS 5 mg p.o. increased cardiac output, cardiac index, and stroke volume index by approximately 60%. With only minor changes in heart rate, ventricular filling pressures decreased by 40%. A decline in pulmonary and systemic vascular resistance (-50%), as well as in systolic, diastolic, and mean pulmonary artery pressures (-35%) were also observed. The effects of 5 mg UDCG 115 BS were comparable to those that occurred with the optimal dose of dobutamine, whereas 10 mg UDCG 115 BS induced significantly more pronounced hemodynamic changes. The effects of UDCG lasted for at least 12 h. No major side effects were observed. Continuous treatment with 10 mg UDCG 115 BS/day for greater than 5 days resulted in a significantly improved response in beta-adrenoceptor stimulation as well as a drop in endogenous plasma catecholamines to nearly normal values. We therefore conclude that UDCG 115 BS, with its unique receptor-independent mechanism of action, may represent a new therapeutic approach in the management of patients with congestive heart failure (CHF).

Comparison of acute haemodynamic effects of dopexamine hydrochloride, dobutamine and sodium nitroprusside in chronic heart failure

Dopexamine hydrochloride (Dopacard) is a new synthetic catecholamine compound, which possesses potent beta 2-adrenergic and DA1-dopaminergic agonistic properties. It is free of alpha-adrenergic activity, has no beta 1-adrenergic activity and is less potent at DA2-dopaminergic receptors than dopamine. In the present study the acute haemodynamic effects of dopexamine hydrochloride were compared to those of dobutamine and nitroprusside in 12 patients with idiopathic congestive cardiomyopathy in an open crossover study. With dopexamine hydrochloride, there were dose-dependent increases from control in cardiac output and stroke volume, decreases in blood pressure, right and left atrial pressure, systemic vascular resistance and pulmonary vascular resistance and little change in heart rate. Similar effects were seen with nitroprusside, apart from a marked increase in heart rate, and with dobutamine, except that systolic aortic blood pressure increased and there was no change in diastolic or mean pressure or pulmonary artery systolic pressure. In general, dopexamine hydrochloride produced effects between those produced by the other two treatments. This suggests that dopexamine with its combined vasodilator and inotropic action has a desirable cardiovascular profile with advantages over the beta 1-receptor agonist dobutamine and the pure vasodilator sodium nitroprusside.