Ever-increasing specialization has made it difficult for many physicians to keep up with therapeutic standards in intensive-care units (ICUs). This issue of Treatment Guidelines offers current recommendations for use of cardiovascular drugs in the ICU for treatment of hypertensive emergencies; shock, cardiac arrest or decompensated heart failure; and ventricular arrhythmias.

Flecainide (Tambocor -3M Pharmaceuticals), first introduced in 1985 for treatment of ventricular arrhythmias, was recently approved by the US Food and Drug Administration for oral use to prevent supraventricular arrhythmias. The indications for using flecainide to treat ventricular arrhythmias were limited after a controlled trial found that post-myocardial infarction patients with asymptomatic ventricular arrhythmias who took the drug had twice as high a mortality rate as patients who took placebo (DS Echt et al, N Engl Med, 324:781, 1991).

Sotalol (hydrochloride (Betapace -Berlex; Sotacor -Bristol Laboratories of Canada), an antiarrhythmic drug that prolongs repolarization (Class III) and also has beta-adrenergic-blocking activity (Class II), was recently approved by the US Food and Drug Administration (FDA) for oral treatment of life-threatening ventricular arrhythmias.

There is no longer any doubt that an implantable cardioverter defibrillator (ICD) can reliably terminate most life-threatening ventricular tachyarrhythmias. The remaining question is who should get one. Guidelines prepared by an American College of Cardiology/American Heart Association task force have recently been published (G Gregoratos et al, Circulation 2002; 106:2145).

The FDA has approved daclatasvir (Daklinza – BMS), an oral direct-acting antiviral drug, for use with sofosbuvir (Sovaldi) for treatment of chronic hepatitis C virus (HCV) genotype 3 infection. Daclatasvir is the first drug approved for this indication that does not require the addition of interferon or ribavirin. It is approved in Japan and Europe in combination with other drugs for treatment of HCV genotypes 1-4.

Cardiac arrest may be due to tachyarrhythmias, bradyarrhythmias, or asystole. Without treatment, permanent damage to the cerebral cortex usually begins within five minutes and is complete in ten. After cardiopulmonary resuscitation (CPR) has been started and electrical defibrillation, when indicated, has been applied, drugs may help promote recovery.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Atrial fibrillation (AF) is the most common arrhythmia in the world. Risk factor modification, anticoagulation, rhythm control, and rate control are the four pillars of its management. American College of Cardiology/American Heart Association (ACC/AHA) guidelines on management of AF were updated recently.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

The FDA has announced changes in the labeling of simvastatin to reduce the risk of myopathy. These changes include limiting the use of the 80-mg maximum dose to patients who have been taking it for 12 months or more without evidence of myopathy and new recommendations for use of simvastatin with other drugs. Simvastatin is available alone (Zocor, and others) and in combination with ezetimibe (Vytorin) and with niacin (Simcor).