Week 3 / Cardiovascular Drugs / Case Study #2
Patient HM has a history of atrial fibrillation and a transient ischemic attack (TIA). The patient has been diagnosed with type 2 diabetes, hypertension, hyperlipidemia and ischemic heart disease. Drugs currently prescribed include the following:
Warfarin 5 mg daily MWF and 2.5 mg daily T, TH, Sat, Sun
Aspirin 81 mg daily
Metformin 1000 mg po bid
Glyburide 10 mg bid
Atenolol 100 mg po daily
Motrin 200 mg 1–3 tablets every 6 hours as needed for pain
In this scenario, Mr. H. M. is given an age of 55 and a behavioral history of smoking.
The medications he is prescribed are listed in the table next to the conditions that I have assumed they are prescribed for.
Male, age 55 / Smoker
Aspirin 81 mg daily
Coumadin 5 mg MWF,
And 2.5 mg T,Th,S,S
TYPE 2 DIABETES
Glyburide 10 mg BID
Metformin 1000 mg BID
– try Glipizide
Atenolol 100 mg QD
Stop Atenolol. Change to ACE Inhibitor,
– Lisinopril *May potentiate Glipizide
Add Statin drug: Simvastatin
ISCHEMIC HEART DISEASE
Aspirin 81 mg po daily
Unknown pain History?
Discourage / Discontinue
Suggest Tylenol for mild pain.
A history of frequency and reason for using Ibuprofen is required from H.M. If this is a rare occasion, it may be benign to use this, but if he is using ibuprofen on a regular basis daily for mild pains, he should be advised to change to Tylenol due to the interactions between Ibuprofen, aspirin and Warfarin which will increase the risk of GI bleeding. Ibuprofen will also reduce the anti-platelet effect of aspirin (Drugs.com, n.d.a; Li, Fries, Li, Lawson, Propert, Diamond, Blair, Fitzgerald & Grosser, 2014).
Atrial Fibrillation and History TIA
Warfarin/Coumadin. H.M. is on low dose of aspirin which has a risk of increased bleeding when used with Coumadin, but the risk is lower than if he were on 325 mg doses. Given his history of ischemic heart disease and hypertension, TIA and atrial fibrillation, Coumadin and aspirin are both appropriate medications; under the assumption PT/INR are within correct therapeutic range.
Ischemic heart disease, Hypertension, Atrial Fibrillation
Atenolol 100 mg po Daily: H.M. is on Atenolol which is a cardio-selective beta blocker. According to the American Heart Association (2014, p. e222) a class I choice for controlling the ventricular rate in atrial fibrillation is a beta blocker or calcium channel blocker. However, H.M.’s diabetes control may be affected by being on a beta blocker as the blocking of beta 1 masks the fight or flight response and symptoms of hypoglycemia, such as tachycardia, could be masked (Reese & Peterson, 2013). This is not the best blood pressure drug for H.M. because of his diabetes history and ischemic heart disease. I am assuming a controlled blood pressure @ 140/80 while on the beta-blocker, with the following recommendation:
A better course of action would be a baseline BUN and creatinine and then initiation of an Angiotensin-converting Enzyme (ACE) inhibitor (Reese & Peterson, 2013; American Heart Association, 2012). The AHA 2012 guidelines for ischemic heart disease, a Class I recommendation in the presence of hypertension and diabetes is for an ACE inhibitor (p.3114). The JNC-8 recommendations for patients < 60, (Mr. H.M. is 55) are to use an ACE or ARB as the initial line of therapy. They do not recommend a beta-blocker as initial hypertensive treatment with diabetes (American Medical Association, 2013, Recommendation #6, p. e7)
That Mr. H.M. is not on a specific medication for hyperlipidemia in the context of his history of ischemic heart disease may mean that his physician wanted him to try to implement lifestyle modifications such as reduced cholesterol and diabetic diet along with exercise and smoking cessation (Barron, 2013). A trial of lifestyle modifications is foregone with diabetes (Barron, 2013) and a statin should be initiated for H.M. now.
The American Diabetic Association (2015) standards of care for diabetes indicate that Statin drugs should be implemented in diabetic patients based on risk factors alone regardless of LDL level. Therefore, although lifestyle modifications are indicated, this should not delay starting H.M on a Statin drug. He will need a baseline liver profile. Lipitor does not require a follow up lipid panel in 6 weeks (Barron, 2013). Lipitor is a started at 10mg and increased based on response. Absorption of Lipitor is the same regardless of when it is taken, morning or evening whereas some statins are best taken at night (Pfizer, 2015).
Type II Diabetes
Evaluation of H.M.’s baseline renal function and hemoglobin A1c is required in order to make any decisions about his diabetic medications. However, because his Metformin 1000 mg bid is the maximum daily dose (Drugs.com, 2015c) and has been combined with Glyburide 10 mg b.i.d., the indication is, that Mr. H.M.’s diabetes was not well controlled with one medication. Although there is no known changes in pharmacodynamics & pharmacokinetics between Metformin and Glyburide, the maximum recommended dose for Glyburide is 12 mg daily (Drugs.com, 2015c) and H.M. is taking 10 mg twice dialy. Glyburide also peaks at 4 hours and has a terminal half life of 10 hours (Drugs.com, n.d.b). If H.M. is truly needing a second drug twice daily, he may benefit from one with a shorter half life such as Glipizide. Starting dose is 2.5-5.0 mg once daily and titrated according to their response (Drugs.com, 2015b). The effects of Glipizide may be potentiated with the use of Lisinopril (ACE) inhibitor (Drugs.com, n.d.b)
Smoking history. H.M. should be strongly encouraged to stop smoking. A study in 2015, for which I could only access the abstract and conclusions, indicates that metformin appears to decrease the risk of mortality from cardiovascular events with smokers (Paul, Klein Majeed & Khunti, 2015).