Inotropes adverse effects

In high concentrations it blocks calcium channels and, thus, exerts prominent negative inotropic effects. Its adverse effects include proarrhythmic effects, worsening of heart failure and (due to (3-adrenoceptor blockade) bradycardia and bronchospasm. 

Flosequinan has a positive inotropic effect and shows a tendency to increase the heart rate, atrioventricular conduction in patients with atrial fibrillation and neurohormonal activation. Although the precise mechanisms involved have remained unclear up to now [29], this drug has been used to treat congestive heart failure (CHF). The FDA approved flosequinan (Manoplax) in 1993. However, the drug was withdrawn a year later because the PROFILE (prospective randomized flosequinan longevity evaluation) study indicated that flosequinan had adverse effects on survival, and that beneficial effects on the symptoms of heart failure did not last beyond the first 3 months of therapy, after which patients on the dmg had a higher rate of hospitalization than patients taking a placebo [14]. 

Adverse effects are generally mild some nausea may occur. Its posihve inotropic action can result in myocardial ischaemia in patients with coronary artery disease. 

These are class IC drugs with similar pharmacological profiles and with the same indication range and adverse effects. They are mainly used for the treatment of severe, lifethreatening ventricular tachyarrhythmias, and non-sustained ventricular tachycardia or high-frequency premature ventricular beats. The main adverse effects are cardiovascular, including proarrhythmic actions and severe negative inotropic effects, especially in patients with impaired cardiac function. Both flecainide and encainide increase the risk of sudden death in patients with myocardial infarction and asymptomatic unsustained ventricular arrhythmias. 

The pharmacokinetic properties of these drugs are set forth in Table 12-5. The choice of a particular calcium channel-blocking agent should be made with knowledge of its specific potential adverse effects as well as its pharmacologic properties. Nifedipine does not decrease atrioventricular conduction and therefore can be used more safely than verapamil or diltiazem in the presence of atrioventricular conduction abnormalities. A combination of verapamil or diltiazem with 3 blockers may produce atrioventricular block and depression of ventricular function. In the presence of overt heart failure, all calcium channel blockers can cause further worsening of heart failure as a result of their negative inotropic effect. Amlodipine, however, does not increase the mortality of patients with heart failure due to nonischemic left ventricular systolic dysfunction and can be used safely in these patients. 

Effects on respiration are similar to those of thiopental at usual anesthetic doses. However, propofol causes a marked decrease in systemic blood pressure during induction of anesthesia, primarily through decreased peripheral resistance. In addition, propofol has greater negative inotropic effects on the heart than etomidate and thiopental. Apnea and pain at the site of injection are common adverse effects of bolus administration. Muscle movements, hypotonus, and (rarely) tremors have also been reported following its use. Clinical infections due to bacterial contamination of the propofol emulsion have led to the addition of antimicrobial adjuvants (eg, ethylenediaminetetraacetic acid and metabisulfite). 

Adverse effects Lidocaine has a fairly wide toxic-to-therapeutic ratio it shows little impairment of left ventricular function, and has no negative inotropic effect. The CNS effects include drowsiness, slurred speech, paresthesia, agitation, confusion, and convulsions cardiac arrhythmias may also occur. 

Adverse effects Verapamil and diltiazem have negative inotropic properties and therefore may be contraindicated in patients with preexisting depressed cardiac function. Both drugs can also cause a decrease in blood pressure caused by peripheral vasodilation. 

Enoximone is an inhibitor of phosphodiesterase type III, and has a positive inotropic effect. Its most common adverse effects are gastrointestinal and cardiac. The gastrointestinal effects include anorexia, nausea, vomiting, and diarrhea (1,2). 

Webster MW, Sharpe DN. Adverse effects associated with the newer inotropic agents. Med Toxicol 1986 l(5) 335-42. 

Appropriate Css values are chosen for the patient based on the disease state being treated, the goal of therapy, and avoidance of adverse effects. The inotropic effects of digoxin occur at lower concentrations than do the chronotropic effects. Therefore, initial serum concentrations of digoxin for the treatment of heart failure generally are 1 ng/mL or less and for the treatment of atrial fibrillation are 1-1.5 ng/mL. Once the appropriate Css is selected, a dose is computed for the patient D/r = CssCl)/E... 

Adverse effects and contraindications of calcium channel blockers are described in Table 16. Verapamil, diltiazem, and first-generation dihydropyridines also should be avoided in patients with acute decompensated heart failure or LV dysfunction because they can worsen heart failure and potentially increase mortality secondary to their negative inotropic effects. In patients with heart failure requiring treatment with a calcium channel blocker, amlodipine is the preferred agent. ... 

Systemic effects are the most important adverse effects of / -blockers. Drug absorbed systematically may produce decreased heart rate, reduced blood pressure, negative inotropic effects, conduction defects, bronchospasm, central nervous system effects, and alteration of serum lipids, and may block the symptoms of hypoglycemia. The -specific agents betaxolol and possibly carteolol (due to ISA) are less likely to produce the systemic adverse effects caused by / -adrenergic blockade, such as the cardiac effects and bronchospasm, but a real risk still exists. The use of timolol as a gel-forming liquid or betaxolol as a suspension allows for administration of less drug per day, and therefore reduces the chance for systemic adverse effects compared with the aqueous solutions. 

Information is limited but the interaetion would seem to be established. Concurrent use need not be avoided but antieipate the need to reduce the dosage of metoprolol and propranolol. Monitor closely because some patients may experience adverse effects. If the suggested mechanism of interaction is correct it is possible (but not confirmed) that other beta blockers that undergo liver metabolism will interact similarly but not those largely excreted unchanged in the urine. See Table 22.1 , (p.833) for the metabolism of some commonly used beta blockers. Also note that propafenone and the beta blockers have negative inotropic effects, which could be additive and result in unwanted cardiodepression. 

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