Presenting History: Eliot is a 74 year old male presented to the clinic with complaints of frequent nose bleeds and several bruises on the body. He is also complaining of runny nose, cough, head and chest congestion. He has a history of atrial fibrillation and is on warfarin 7mg PO daily. As he experiencing heart burn, he started to take over the counter cimetidine for last three weeks. His physical examination shows, blood pressure 180/95, irregular heart rhythm with a heart rate of 75 and he weighs 95 KG. His abnormal lab value includes, serum Digoxin level of 3.8 ng/ml (Normal serum digoxin level is 0.5–2 ng/mL) and INR value of 4.8 (Normal INR level is 2.0 - 3.0).
What problems should be identified in this patient?
Based on Eliot’s presenting …show more content…
The reduced form of vitamin k is essential for the carboxylation of the terminal regions of the vitamin K proteins, factors II, VII, IX, and X. Without carboxylation, these vitamin K–dependent clotting factors cannot become activated. Warfarin interferes with the cyclic restoration of reduced levels of vitamin K. Therefore, warfarin indirectly reduces the synthesis of these clotting factors (Wigle et al., 2013).
Cimetidine: Cimetidine is a histamine-2 receptor antagonist. The mechanism of action of cimetidine is as a histamine H2 receptor antagonist. It inhibits histamine binding to histamine H2 receptors. Cimetidine inhibits gastric acid secretion as well as pepsin and gastrin output (PubChem, 2017).
Pseudoephedrine: Pseudoephedrine is a phenethylamine that is used mainly for respiratory tract decongestion. Pseudoephedrine displaces norepinephrine from storage vesicles in presynaptic neurones, thus releasing norepinephrine into the neuronal synapses where it stimulates primarily alpha-adrenergic receptors. This receptor stimulation results in vasoconstriction and decreases nasal and sinus congestion (PubChem, 2017).
What do you think is contributing to the patient’s …show more content…
What is the clinical significance of these interactions?
Warfarin- Cimetidine interaction: Anticoagulant drugs interact with many drugs including over the counter medications such as cimetidine. When warfarin and cimetidine is taken together, the effect of warfarin will be increased. As a result frequent nose bleeds and bruises can occur. Reducing the effect of warfarin will lower the INR and stop the bleeding episodes. Henceforth, cimetidine to be discontinue from Eliot’s medication list and an alternative antacid such as Pepcid will be considered at this time (Anticoagulation EUROPE (UK), 2015).
Digoxin- Pseudoephedrine interaction: Using digoxin together with pseudoephedrine can cause an irregular heart rhythm. Pseudoephedrine is a sympathomimetic agent, which can activate β-receptors of the heart leading to increases in heart rate and α-receptors in vascular smooth muscle leading to vasoconstriction and increases in blood pressure (Sager et al., 2013). Consequently, patients with heart disease should consult with clinicians before using pseudoephedrine or similar medications. Therefore, cimetidine should be discontinued from Eliot’s medication list and an alternative antihistamine such as cetirizine should be considered to improve Eliot’s nasal
What problems should be identified in this patient?
Based on Eliot’s presenting …show more content…
The reduced form of vitamin k is essential for the carboxylation of the terminal regions of the vitamin K proteins, factors II, VII, IX, and X. Without carboxylation, these vitamin K–dependent clotting factors cannot become activated. Warfarin interferes with the cyclic restoration of reduced levels of vitamin K. Therefore, warfarin indirectly reduces the synthesis of these clotting factors (Wigle et al., 2013).
Cimetidine: Cimetidine is a histamine-2 receptor antagonist. The mechanism of action of cimetidine is as a histamine H2 receptor antagonist. It inhibits histamine binding to histamine H2 receptors. Cimetidine inhibits gastric acid secretion as well as pepsin and gastrin output (PubChem, 2017).
Pseudoephedrine: Pseudoephedrine is a phenethylamine that is used mainly for respiratory tract decongestion. Pseudoephedrine displaces norepinephrine from storage vesicles in presynaptic neurones, thus releasing norepinephrine into the neuronal synapses where it stimulates primarily alpha-adrenergic receptors. This receptor stimulation results in vasoconstriction and decreases nasal and sinus congestion (PubChem, 2017).
What do you think is contributing to the patient’s …show more content…
What is the clinical significance of these interactions?
Warfarin- Cimetidine interaction: Anticoagulant drugs interact with many drugs including over the counter medications such as cimetidine. When warfarin and cimetidine is taken together, the effect of warfarin will be increased. As a result frequent nose bleeds and bruises can occur. Reducing the effect of warfarin will lower the INR and stop the bleeding episodes. Henceforth, cimetidine to be discontinue from Eliot’s medication list and an alternative antacid such as Pepcid will be considered at this time (Anticoagulation EUROPE (UK), 2015).
Digoxin- Pseudoephedrine interaction: Using digoxin together with pseudoephedrine can cause an irregular heart rhythm. Pseudoephedrine is a sympathomimetic agent, which can activate β-receptors of the heart leading to increases in heart rate and α-receptors in vascular smooth muscle leading to vasoconstriction and increases in blood pressure (Sager et al., 2013). Consequently, patients with heart disease should consult with clinicians before using pseudoephedrine or similar medications. Therefore, cimetidine should be discontinued from Eliot’s medication list and an alternative antihistamine such as cetirizine should be considered to improve Eliot’s nasal