McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 3 0 Adrenergic agonists

CRITICAL THINKING SCENARIO Adrenergic agonist toxicity

THE SITUATION M.C. is a 26-year-old man who has recently moved from Western Australia to Tasmania. He has been suffering from sinusitis, runny nose and cold-like symptoms for 2 weeks. He appears at an outpatient hospital with complaints of headache, “jitters”, inability to sleep, loss of appetite and a feeling of impending doom. He states that he feels “on edge” and has not been productive in his job as a watch repairman and jeweller. According to his history, M.C. has been treated with several different drugs for nocturnal enuresis, a persisting childhood problem. Only ephedrine, which he has been taking for 2 years, has been successful (an off-label use of the drug). He has no other significant health problems. He denies any side effects from the use of ephedrine but does admit to self-medicating his nagging cold with OTC preparations—a nasal spray used four times a day and a combination decongestant–pain reliever. A physical examination reveals a pulse of 104 beats/minute, blood pressure 154/86 mmHg, and respiration 16/minute. M.C. appears flushed and slightly diaphoretic. CRITICAL THINKING What are the important care implications for M.C.? Think about the problems that confront a person in a new area seeking healthcare for the first time. What could be causing the problems that M.C. presents with? The diagnosis of ephedrine overdose was eventually made based on the person’s history of OTC drug use and the presenting signs and symptoms. Keeping in mind that this diagnosis means that M.C. has an overstimulated sympathetic stress reaction, what other physical problems can be anticipated? Overwhelming feelings of anxiety and stress are influencing M.C.’s response to work and healthcare. Given this fact, how may the health professional best deal with explaining the problem and how it could have happened—without making the person feel uninformed or that the practice of his former healthcare provider is being questioned? What treatment should be planned and what teaching points should be covered for M.C.? DISCUSSION The first step in caring for M.C. is establishing a trusting relationship to help alleviate some of the anxiety he is feeling. Being in a new state and seeking healthcare in a new setting can be very stressful for people under normal circumstances. In M.C.’s case, the sympathomimetic effects

of the drugs that he has been taking make him feel even more anxious and jittery. A careful history will help to determine whether there are any underlying medical problems that could be exacerbated by these drug effects. A review of M.C.’s nocturnal enuresis and the treatments that have been tried will enhance understanding of his former healthcare and suggest possible implications for further study. This questioning will also reassure M.C. that he is an important member of the health team and that the information he has to offer is valued. A careful review of the OTC drugs that M.C. has been using will be informative for the person, as well as for the healthcare providers, who have not actually checked OTC drugs for those specific ingredients, because combining them to ease signs and symptoms often results in toxic levels and symptoms of overdose. Many of these preparations contain sympathomimetics, such as phenylephrine, which will have additive effects to the ephedrine. M.C. will need a full teaching program about the effects of his ephedrine and which OTC drugs to avoid. The treatment for his current problems involves withdrawal of the OTC drugs; when these drug levels fall, the signs and symptoms will disappear. M.C. may also wish to avoid nicotine and caffeine because these stimulants could increase his “jitters”. To build trust and ensure that the underlying cause of the problem was drug toxicity, M.C. should receive written instructions that highlight warning signs to report, including chest pain, palpitations and difficulty voiding. He also should be given the healthcare provider’s telephone number with instructions to call the next day and report on his health status. Finally, specimens of nasal discharge should be cultured and antibiotic treatment prescribed, if appropriate. CARE GUIDE FOR M.C.: ADRENERGIC AGONIST TOXICITY Assessment: History and examination Assess the person’s history of drug allergies, cardiovascular dysfunction, pheochromocytoma, narrow-angle glaucoma, prostatic hypertrophy, thyroid disease or diabetes, as well as concurrent use of MAO inhibitors, tricyclic antidepressants, reserpine, ephedrine or urinary alkalinisers. Focus the physical examination on the following: CV: Blood pressure, pulse rate, peripheral perfusion and ECG CNS: orientation, affect, reflexes, peripheral sensation and vision