0-Adrenergic drugs

The adrenergic dragp produce pharmacologic effects similar to the effects that occur in die body when die adrenergic nerves and the medulla are stimulated. The primary effects of these drugp occur on the heart, the blood vessels, and die smooth muscles, such as die bronchi. A basic knowledge of the nervous system is necessary to understand tiiese drugp and how they work in the body. 

The CNS consists of die brain and die spinal cord and receives, integrates, and inteqirets nerve impulses. 

The PNS is die term used to describe all nerves outside of die brain and spinal cord. The PNS connects all parts of die body witii die CNS. 

The PNS is further divided into the somatic nervous system and the autonomic nervous system. The somatic branch of the PNS is concerned witii sensation and voluntary movement. The sensory part of the somatic nervous system sends messages to the brain concerning die internal and external environment, such as sensations of heat, pain, cold, and pressure The voluntary part of die somatic nervous system is concerned witii die voluntary movement of skeletal muscles, such as walking, chewing food, or writing a letter. 

The autonomic branch of die PNS is concerned witii functions essential to the survival of the organism. Functional activity of the autonomic nervous system 

The drugs described in this chapter are used to treat a variety of disorders, ranging from severe cardiovascular and respiratory problems to symptoms of the common cold. Because these drugs are widely used in cardiovascular disease and other disorders, many patients seen in physical therapy and occupational 

The Austrian pharmacologist Heribert Konzett (1912-2004) had discovered in 1940 isoprenaUne, which should become the prototype of p-selective sympathomimetics. Due to its bronchodilatory properties, but without causing hyper-tention, it was considered the drug of choice to treat asthmatic attacks. With almost equally strong effect on pj- and p2-receptors, it was of concern, that isoprenaline acts as a very potent cardiac stimulant. Further structural optimisation then led to more selective pj-sympathomimetics, like dobutamine, for the treatment of heart failure and cardiogenic shock, while selective p2-sympathomimetics were aimed at safer therapies of bronchial asthma. 

P2-Sympathomimetics can be grouped into different structural clusters, which aU take into account, that modification of the catechol moiety affects 

Indirecdy acting sympathomimetics release noradrenaline from the nerve endings and/or inhibit its re-uptake. Thereby, the noradrenaline concentration in the synaptic cleft is raised, and the sympathetic tone therefore increased. After repeated administration of higher doses, this effect is however restricted by the limited supply of newly synthesised noradrenaline. Typical representatives are ephedrine and the amphetamines (Fig. 6.39). The high polarity of catecholamines, associated with the two aromatic hydroxyl-groups, necessitates intravenous administration, and confines their activity to the periphery. Ephedrine, amphetamine, and as well methamphetamine exhibit in addition to their peripheral sympathomimetic effect also a central stimulating activity. 

39 Indirect sympathomimetics with central stimulating effect. 

41 Galina Kulakova, cross country skier from the former USSR and multiple Olympic gold medalist at the Winter Games in 1972, was stripped of her bronze medal at the 1976 Winter Olympics in Innsbruck, when it was discovered that her nasal spray contained ephedrine. [98] 

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Adrenergic receptor 2 Amino acid variants appear to be associated with receptor function and agonist induced down regulation. Some variants may predispose to some types of asthma and modulate action of (3-2-adrenergic drugs. 

Discuss the types of shock, physiologic responses of shock, and the use of adrenergic drugs in the treatment of shock. 

Discuss the uses, general drug actions, contraindications, precautions, interactions, and adverse reactions associated with the administration of adrenergic drugs. 

Discuss important preadministration and ongoing assessment activities the nurse should perform on the patient taking adrenergic drugs. 

List some nursing diagnoses particular to a patient taking the adrenergic drugs. 

Discuss ways to promote an optimal response to therapy, how to manage common adverse reactions, and important points to keep in mind when educating patients about the use of adrenergic drugs. 

Generally, adrenergic drugs produce one or more of tlie following responses in varying degrees ... 

SUM MARY DRUG TABLE ADRENERGIC DRUGS (Continued)... 

The adrenergic drugs are useful in improving hemodynamic status by improving myocardial contractility and increasing heart rate, which results in increased cardiac output. Peripheral resistance is increased by vasoconstriction. In cardiogenic shock or advanced shock associated with low cardiac output, die adrener-... 

Prolonged high-dose therapy of the adrenergic drugs can produce cyanosis and tissue necrossof distal extremities It is important to remember to use the lowest posable dose that producesan adequate response for the shortest period of time. The nurse monitors the patient s extremitiescloseiy for any signs of cyanosis... 

Discuss the preadministration assessment for a patient requiring an adrenergic drug for hypotension. 

Describe what information is important to include in an education session for a patient taking an adrenergic drug for nasal cojigestion. 

The nurse should withhold the administration of a p -adrenergic drug, such as propranolol (Inderal), and contact the primary health care provider if the patient has a heart rate of less than 60 bpm or if there isany irregularity in the patient s heart rate or rhythm. 

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