Chapter 10 Principles of Pharmacology

Part 1 You and your partner are on your way back to the station when you are called to an assisted-living facility for an unknown medical complaint. Upon arrival, you are met in the lobby by the patient’s son, who brings you back to the apartment. The door to the apartment is open when you get there, and you see an older man sitting on a recliner in the living room. As you approach him and introduce yourself, you note that he is pale and slightly diaphoretic.

Part 1 (cont’d) He tells you that he has been feeling “skips in his chest” for the past couple of hours and that he becomes extremely light-headed when he stands. He also says he feels “a little winded” and states that his vision “is off.” He denies having any chest pain, headaches, or any other symptoms. He states that he takes heart medications but cannot recall what they are. His son recalls that his father keeps a list of his medications and medical history on an index card in his wallet.

Part 1 (cont’d) 1.What is your potential differential diagnosis? 2.What types of medications might your patient be taking?

Part 2 You ask your partner to place the patient on supplemental oxygen via nasal cannula and obtain a set of vital signs while you begin to question the patient further about his current illness and past medical history. The patient’s son explains that his father was discharged from the hospital last week for problems associated with his heart. He hands you an index card that contains his father’s medical history and list of medications. You note that the patient has a history of atrial fibrillation, congestive heart failure, and stable angina.

Part 2 (cont’d) Daily medications include digoxin, mg every morning; Coumadin, 3 mg every morning; Lasix, 60 mg with breakfast and 60 mg at bedtime; Cardizem CD, 240 mg every morning; and nitroglycerin as required for chest pain. As you are looking over the list, the son pulls you over to side of the room and quietly expresses his concern about his father’s medication compliance, as he has noticed that his father can be forgetful and may be taking his medication more often than it is prescribed.

Part 2 (cont’d) 3.What type of drug is Cardizem, and how does it work?

Part 3 You perform a physical exam on the patient while your partner prepares an IV setup. You document the following findings: JVD; moderate crackles in the lower lobes bilaterally; mild swelling around the ankles; and a slow, irregular, weak radial pulse. You ask the patient to describe his vision problems. He explains that for the past 2 days his sight has been blurry and objects have had a yellow-green circle around them. He jokingly tells you that this blurriness interferes with him being able to complete the morning crossword puzzle.

Part 3 (cont’d) You establish an 18-gauge IV in the right AC and begin to administer a 200-mL fluid bolus. Before leaving for the hospital you perform a 12-lead ECG, which shows atrial fibrillation at a rate in the 40s with frequent PVCs. Recalling the information on cardiac medication from a recent in-service you know that both digoxin and Cardizem CD can lower the heart rate. You also know that the patient is symptomatic from the low heart rate and PVCs. Unsure of how to proceed with treatment, you decide to contact medical control for guidance.

Part 3 (cont’d) 4.Does the patient present with signs and symptoms of possible drug toxicity? If so, which medications are in question? 5.What treatment will increase the patient’s blood pressure?

Part 4 You make contact with medical control, where the physician advises you to administer 500 mg of calcium chloride IV and closely monitor the patient’s vital signs. Upon safe transfer of the patient at the hospital the physician explains that the patient is likely experiencing the effects of digitalis and calcium channel blocker toxicity.

Part 4 (cont’d) 6.What does it mean when a medication has a low therapeutic index? 7.What occurs when one drug potentiates a second drug?