Cardiac drug , intravenous injection

The rate of absorption of a local anesthetic into the bloodstream is affected by the dose administered, the vascularity at the site of injection, and the specific physicochemical properties of the drug itself. Local anesthetics gain entrance into the bloodstream by absorption from the injection site, direct intravenous injection, or absorption across the mucous membranes after topical application. Direct intravascular injection occurs accidentally when the needle used for infiltration of the local anesthetic lies within a blood vessel, or it occurs intentionally when Udocaine is used for the control of cardiac arrhythmias. 

Table 3 An example of an intravenous injection solution formulation for the cardiac drug digoxin as...

Epinephrine usually Is administered slowly by Intravenous (IV) Injection to relieve acute asthmatic attacks not controlled by other treatments. Intravenous Injection produces an Immediate response. Use of EPI with drugs that enhance cardiac arrhythmias (digitalis or quinidine) Is not recommended. Tricyclic antidepressants and MAO Inhibitors will potentiate the effects of EPI on the heart. Epinephrine should be used with caution In Individuals suffering from hyperthyroidism, cardiovascular disease, hypertension, or diabetes. Adverse effects Include palpitations, tachycardia, sweating, nausea and vomiting, respiratory difficulty, dizziness, tremor, apprehension, and anxiety. 

II. Toxic dose. The toxic dose is highly variable and depends on individual tolerance, the route of administration, and the presence of other drugs, as well as other factors. Rapid intravenous injection or smoking may produce transient high brain and heart levels, resulting in convulsions or cardiac arrhythmias, whereas the same dose swallowed or snorted may produce only euphoria. 

I. Pharmacology. Isoproterenol is a catecholamine-like drug that stimulates beta-adrenergic receptors (beta-1 and -2). Pharmacologic properties include positive inotropic and chronotropic cardiac effects, periphery vasodilation, and bron-chodilation. Isoproterenol is not absorbed orally and shows variable and erratic absorption from sublingual and rectal sites. The effects of the drug are rapidly terminated by tissue uptake and metabolism effects persist only a few minutes after intravenous injection. 

In addition to studying hemodynamic changes caused by liberated histamine, plasma epinephrine and norepinephrine levels have been investigated following injection of morphine. In a study of a patient who experienced an anaphylactoid response following the intravenous injection of morphine 0.3 mg/kg, plasma catecholamines were increased and this was accompanied by decreases in systemic vascular resistance and arterial blood pressure. In another study, intravenous morphine increased cardiac output, histamine, and epinephrine plasma concentrations and decreased arterial blood pressure and systemic vasculature resistance in adult subjects with no history of drug allergy or clinical evidence of cardiovascular, pulmonary, or metabolic disease. 

Egeberg studied a number of acute states and found that a rise of factor VIII was associated with the induction of nonspecific fever (E6, ElO), intravenous infusion of serum (E7), intramuscular injection of blood (E8) or intravenous infusion of hemolyzed blood (E2), drug-induced diuresis in a patient with cardiac edema (Ell), and surgical operations (El). In the very acute changes, factor VIII alone rose in concentration, but where the process occupied several days there were normally associated increases in fibrinogen and in factor V. Other clotting factors remained at their previous levels. These investigations were all made in persons with normal hemostasis. 

I. Pharmacology. The neuronal membrane-stabilizing actions of phenytoin make this a popular drug for sustained control of aoute and ohronic seizure disorders and a useful drug for certain cardiac arrhythmias. Because of the relatively slow onset of anticonvulsant action, phenytoin is usually administered after diazepam. At serum concentrations considered therapeutic for seizure control, phenytoin acts similarly to lidocaine to reduce ventricular premature depolarization and suppress ventricular tachycardia. After intravenous administration, peak therapeutic effects are attained within 1 hour. The therapeutic serum concentration for seizure control is 10-20 mg/L. Elimination is nonlinear, with an apparent half-life averaging 22 hours. Fosphenytoin, a prodrug of phenytoin for intravenous use, is converted to phenytoin after injection, with a conversion half-life of 8-32 minutes. 

PhiUips KA, Flirsch GA, Epstein DH, Preston KL. Cardiac comphcations of unwitting co-injection of qirinine/qviinidine with heroin in an intravenous drug user. J Gen Intern Med December 2012 27(12) 1722-5. 

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