Epinephrine drug interactions

Drug interactions bupivacaine solutions containing epinephrine or norepinephrine administered to patients receiving monoamine oxidase inhibitors or tri-cychc antidepressants may produce severe, prolonged hypertension. Concurrent administration of vasopressor drugs added to bupivacaine/vasoconstrictor solutions and of ergot-type oxytocic drugs may cause severe, persistent hypertension or cerebrovascular accidents. 

Adrenergic. Relating to epinephrine (adrenaline) or norepinephrine (noradrenaline). Commonly used to describe neurons that utilize norepinephrine as a neurotransmitter and the drugs that interact with these neurons. 

The answers are 25-e, 26-b, 27-a. (Hardmanr pp 67—68. Katzung, pp 30, 134.) Anaphylaxis refers to an acute hypersensitivity reaction that appears to be mediated primarily by immunoglobulin E (IgE). Specific antigens can interact with these antibodies and cause sensitized mast cells to release vasoactive substances, such as histamine. Anaphylaxis to penicillin is one of the best-known examples the drug of choice to relieve the symptoms is epinephrine. 

Drug/Lab test interactions Isoproterenol causes false elevations of bilirubin as measured in vitro by a sequential multiple analyzer. Isoproterenol inhalation may result in enough absorption of the drug to produce elevated urinary epinephrine values. Although small with standard doses, the effect is likely to increase with larger doses. 

Drugs that may interact with antipsychotics include alcohol, CNS depressants, antihypertensive agents, dopamine, epinephrine, and charcoal. 

Drugs metabolized by COMT Administer drugs known to be metabolized by COMT (ie, isoproterenol, epinephrine, norepinephrine, dopamine, dobutamine, methyidopa, apomorphine, isoetherine, bitolterol) with caution in patients receiving entacapone regardless of the route of administration (including inhalation), as their interaction may result in increased heart rates, arrhythmias, and excessive changes in blood pressure. 

Adrenoceptors interact not only with norepinephrine but also with the adrenal medullary hormone epinephrine and a number of chemically related drugs. However, the responses produced by the drugs in different autonomic structures differ quantitatively or qualitatively from one another. 

Many adrenomimetic drugs produce responses by interacting with the adrenoceptors on sympathetic effector cells. An examination of Table 9.1 reveals that sympathetic effectors have activity at i-, aj-, Pr, or P2-adrenoreceptors or in some cases, combinations of these adrenoceptors. Adrenomimetic drugs vary in their affinities for each subgroup of adrenoceptors. Some, like epinephrine, have a high affinity for all of the adrenocep-... 

The effect of a given adrenomimetic drug on a particular type of effector cell depends on the receptor selectivity of the drug, the response characteristics of the effector cells, and the predominant type of adrenoceptor found on the cells. For example, the smooth muscle cells of many blood vessels have only or predominantly a-adrenoceptors. The interaction of compounds with these adrenoceptors initiates a chain of events in the vascular smooth muscle cells that leads to activation of the contractile process. Thus, norepinephrine and epinephrine, which have high affinities for a-adrenoceptors, cause the vascular muscle to contract and the blood vessels to constrict. Since bronchial smooth muscle contains p2-adrenoceptors, the response in this tissue elicited by the action of p2-adrenoceptor agonists is relaxation of smooth muscle cells. Epinephrine and isoproterenol, which have high affinities for p2-adrenoceptors, cause relaxation of bronchial smooth muscle. Norepinephrine has a lower affinity for p2-adrenoceptors and has relatively weak bronchiolar relaxing properties. 

Newer MAOI drugs are selective for the MAO-A subtype of the enzyme, and are less likely to interact with foods or other drugs. Monoamine oxidase (MAO) inactivates monoamine substances, many of which are, or are related to, neurotransmitters. The central nervous system mainly contains MAO-A, whose substrates are adrenaline (epinephrine), noradrenaline (norepinephrine), metanephrine, and 5-hydroxyti7ptamine (5-HT), whereas extra-neuronal tissues, such as the liver, lung, and kidney, contain mainly MAO-B which metabolises p-phenylethylamine, phenylethanolamine, o-tyramine, and benzylamine. 

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