Pharmacokinetics and pulmonary extraction of clevidipine, a new vasodilating ultrashort-acting dihydropyridine, during cardiopulmonary bypass

Management of hypertensive crises in the elderly

Hypertensive crises are elevations of blood pressure higher than 180/120 mmHg. These can be urgent or emergent, depending on the presence of end organ damage. The clinical presentation of hypertensive crises is quite variable in elderly patients, and clinicians must be suspicious of non-specific symptoms. Managing hypertensive crises in elderly patients needs meticulous knowledge of the pathophysiological changes in them, pharmacological options, pharmacokinetics of the medications used, their side effects, and their interactions with other medications. Clevidipine, nicardipine, labetalol, esmolol, and fenoldopam are among the preferred choices in the elderly due to their efficacy and tolerability. Nitroprusside, hydralazine, and nifedipine should be avoided, unless there are no other options available, due to the high risk of complications and unpredictable responses.

Clevidipine: a review of its use for managing blood pressure in perioperative and intensive care settings

The ultrashort-acting dihydropyridine calcium channel antagonist clevidipine (Cleviprex(®)) has a rapid onset and offset of effect and reduces blood pressure (BP) by decreasing arteriolar resistance without affecting venous capacitance vessels. This article reviews the clinical efficacy and tolerability of intravenous clevidipine when used to manage BP in perioperative and intensive care settings, as well as summarizing its pharmacological properties. Intravenous clevidipine effectively treated preoperative and postoperative hypertension in patients undergoing cardiac surgery, according to the results of the randomized, multicentre, double-blind, phase III ESCAPE-1 and ESCAPE-2 trials. The randomized, open-label, multicentre, phase III ECLIPSE trials indicated that in terms of keeping systolic BP within the target range, clevidipine was more effective than nitroglycerin or sodium nitroprusside perioperatively and had similar efficacy to nicardipine postoperatively in cardiac surgery patients. In small, double-blind trials in patients undergoing coronary artery bypass graft surgery, perioperative clevidipine was noninferior to nitroglycerin, and postoperative clevidipine had similar efficacy to sodium nitroprusside. Noncomparative studies demonstrated that clevidipine provided rapid BP control in patients with acute neurological injuries (including intracerebral haemorrhage, subarachnoid haemorrhage and acute ischaemic stroke), and was not associated with 'overshoot' in the vast majority of patients. Intravenous clevidipine was generally well tolerated and was usually associated with no reflex tachycardia or only very modest increases in heart rate. In conclusion, intravenous clevidipine is a valuable agent for the management of BP in perioperative and intensive care settings.

Clevidipine : a state-of-the-art antihypertensive drug under the scope

INTRODUCTION

Clevidipine butyrate is the first intravenous antihypertensive drug to be approved by the FDA over the last decade. This medication is approved for use in the USA, Australia and New Zealand, but is still pending for approval in Europe. It is a new agent that might change the current management for severe acute hypertension in the critical care, emergency and perioperative areas.

AREAS COVERED

This systematic review summarizes the pharmacological and clinical characteristics of this third-generation dihydropyridine intravenous calcium channel blocker, and was done using the literature available from the first publication in 1999 up until now, including the pivotal trials that led to its approval.

EXPERT OPINION

This agent is arterially selective, has an ultrashort half-life, with no CYP-mediated interactions with other medications and is easily titratable. These characteristics place it in a unique category compared with other commonly used antihypertensives. Clevidipine butyrate reaches target systolic blood pressure in more than 90% of patients, within 30 min. It has a low incidence of adverse reactions and is generally well tolerated. The main goal of this review is to provide healthcare providers with a comprehensive appraisal of this promising medication.

Role of clevidipine butyrate in the treatment of acute hypertension in the critical care setting: a review

Acutely elevated blood pressure in the critical care setting is associated with a higher risk of acute end-organ damage (eg, myocardial ischemia, stroke, and renal failure) and perioperative bleeding. Urgent treatment and careful blood pressure control are crucial to prevent significant morbidity. Clevidipine butyrate (Cleviprex) is an ultrashort-acting, third-generation intravenous calcium channel blocker. It is an arterial-selective vasodilator with no venodilatory or myocardial depressive effects. Clevidipine has an extremely short half-life of approximately 1 minute as it is rapidly metabolized by blood and tissue esterases. These metabolites are then primarily eliminated through urine and fecal pathways. The rapid onset and the short duration of action permit tighter and closer adjustment of the blood pressure than is possible with other intravenous agents.

Parenteral clevidipine for the acute control of blood pressure in the critically ill patient: a review

Clevidipine is a new calcium channel blocker of the dihydropyridine class that is characterized by its ultra-short onset of action, vascular selectivity, small volume of distribution and extremely high clearance that coupled together result in an extremely short half-life of approximately 1 minute therefore permitting a rapid titration to the desired effect. Structurally similar to other dihydropyridines, clevidipine has an extra ester link that allows its rapid hydrolization to its inactive carboxylic acid metabolite in blood and extravascular tissues. Clevidipine’s metabolites are then primarily eliminated through urine and fecal pathways. Clevidipine does not affect cytochrome P450 (CYP) enzymes and no clinically significant drug interactions have been determined. In trials like the ESCAPE trials, ECLIPSE, and VELOCITY, clevidipine demonstrated a significant improvement in the management of acute hypertension when compared to placebo as shown in both ESCAPE trials. The ECLIPSE trial compared clevidipine to other drugs currently used in the management of acute hypertension, such as sodium nitroprusside, nitroglycerine and nicardipine; clevidipine was superior to all three agents; in providing blood pressure support, safety and tolerability clevidipine also showed a significant reduction in mortality rate (4.7% vs 1.7%, P =0.0445) when compared to sodium nitroprusside. In the VELOCITY trial clevidipine demonstrated a reduction in blood pressure of 6% at the 3 minute mark, 15% within 9.5 minutes and 27% at the 18 hour mark.

Clevidipine Butyrate Injectable Emulsion

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Clevidipine effectively and rapidly controls blood pressure preoperatively in cardiac surgery patients: the results of the randomized, placebo-controlled efficacy study of clevidipine assessing its preoperative antihypertensive effect in cardiac surgery-1

BACKGROUND

Clevidipine is an ultrashort-acting, third-generation IV dihydropyridine calcium channel blocker that exerts rapid and titratable arterial blood pressure reduction, with fast termination of effect due to metabolism by blood and tissue esterases. As an arterial-selective vasodilator, clevidipine reduces peripheral vascular resistance directly, without dilating the venous capacitance bed. In this randomized, double-blind, placebo-controlled multicenter trial we evaluated the efficacy and tolerability of clevidipine in treating preoperative hypertension.

METHODS

One-hundred-fifty-two patients scheduled for cardiac surgery with current or recent hypertension were randomized to receive clevidipine or placebo preoperatively. One-hundred-five patients met postrandomization entrance criteria (systolic blood pressure [SBP] > or =160 mm Hg after inserting an arterial catheter) for reduction by > or =15% from baseline in SBP. The patients thus received infusions of clevidipine (0.4-8.0 microg x kg(-1) x min(-1)) or 20% lipid emulsion (placebo) for at least 30 min. Treatment failure was defined as failure to reduce SBP by > or =15% from baseline or discontinuance of drug for any reason.

RESULTS

Patients treated with clevidipine demonstrated a 92.5% rate of treatment success and a significantly lower rate of treatment failure (7.5%, 4 of 53) than patients receiving placebo (82.7%, 43 of 52; P < 0.0001). Clevidipine achieved target blood pressures (SBP reduced by > or =15%) at a median of 6.0 min (95% confidence interval 6-8 min). A modest increase in heart rate from baseline occurred during clevidipine administration. Adverse events for each treatment group were similar.

CONCLUSIONS

Clevidipine was effective in rapidly decreasing blood pressure preoperatively to targeted blood pressure levels and was well tolerated in patients scheduled for cardiac surgery.

Pharmacodynamic, Pharmacokinetic and Clinical Effects of Clevidipine, an Ultrashort-Acting Calcium Antagonist for Rapid Blood Pressure Control

Clevidipine is an ultrashort-acting vasoselective calcium antagonist under development for short-term intravenous control of blood pressure. Studies in animals, healthy volunteers and patients have demonstrated the vascular selectivity and rapid onset and offset of antihypertensive action of clevidipine, a synthetic 1,4-dihydropyridine that inhibits L-type calcium channels. Clevidipine has a high clearance (0.05 L/min/kg) and is rapidly hydrolyzed to inactive metabolites by esterases in arterial blood. Its half-life in patients undergoing cardiac surgery is less than one min. Unlike sodium nitroprusside, a drug commonly used for the short-term control of blood pressure, which dilates both arterioles and veins, clevidipine reduces blood pressure through a selective effect on arterioles. As documented in animals and in cardiac surgical patients, clevidipine reduces peripheral resistance without any undesirable effect on cardiac filling pressure. It increases stroke volume and cardiac output. In anesthetized patients undergoing cardiac surgery clevidipine, unlike sodium nitroprusside, does not increase heart rate. In addition of having a favorable hemodynamic profile, suitable for rapid control of blood pressure, clevidipine protects against ischemia/reperfusion injuries, which are not uncommon during major surgery. In anesthetized pigs, clevidipine reduced infarct size after 45 min-long myocardial ischemia by 40%. In rats, renal function and splanchnic blood flow were better maintained when blood pressure was reduced with clevidipine than with sodium nitroprusside. Clevidipine was well tolerated in Phases I and II of clinical trials that included more than 300 individuals/patients. Since there are no known compounds with similar pharmacodynamic and pharmacokinetic properties in clinical development, it is anticipated that clevidipine, a compound tailored to the needs of anesthesiologists, has the potential to become a drug of choice for controlling blood pressure during surgical procedures.

Rapid disappearance of protamine in adults undergoing cardiac operation with cardiopulmonary bypass

BACKGROUND

Despite long use of protamine in cardiac operations, neither protamine concentrations nor pharmacokinetics have been reported in patients.

METHODS

Twenty-eight patients (age, 26 to 80 years) undergoing various cardiac surgical procedures gave their consent to receive 250 mg of protamine sulfate administered intravenously by an infusion pump during 5 minutes. Protamine was administered at the usual intraoperative time after separation from cardiopulmonary bypass for reversal of heparin. Timed arterial blood samples were obtained after protamine infusion. Blood plasma was subjected to solid-phase extraction and high-performance liquid chromatography. Total (free + heparin-bound) protamine concentration versus time data were subjected to pharmacokinetic modeling.

RESULTS

Twenty-six patients completed the study. Total plasma protamine concentrations declined rapidly. Model-independent pharmacokinetic analysis revealed median (range) values as follows: volume of distribution, 5.4 L (0.82 to 34 L); clearance, 1.4 L/min (0.61 to 3.8 L/min); and half-life, 4.5 min (1.9 to 18 min). Schwarz-Bayesian criterion identified a two-compartment exponential model with adjustment for weight in the central compartment volume of distribution as performing better than other compartmental or Michaelis-Menten models.

CONCLUSIONS

Protamine has a very short (approximately 5 minutes) half-life after a single 250-mg dose in adult patients. This short half-life could underlie recurrent anticoagulation after initial apparent reversal of heparin.