Pharmacotherapy for Cardiovascular Disorders

Behavior Factor’s Influence on Pharmacokinetic and Pharmacodynamic Processes

HM is taking a number of medications, not all of which are compatible with each other. Some of them are also not compatible with some foods and beverages. Warfarin, Metformin, and Glyburide all have a moderate level of interaction with alcohol, so it should be avoided when taking any of them let alone all three of them. Mayo Clinic (2018) lists other foods and beverages that should be avoided when taking Warfarin include cranberries, cranberry juice, foods high in vitamin K such as soybean and canola oils, spinach and broccoli, garlic and black licorice (Mayo Clinic, 2018). These foods can cause problems such as increased or reduced medication effectiveness. According to Harvard Medical School (2013) the foods listed can cause arrhythmia which could account for HM’s atrial fibrillation (Harvard Health Publishing, 2013). But it is not just in his diet that HM must be cautious with the medications he is taking.

HM’s behavior may have an effect on the effectiveness of the medications. For instance, if he does not take Warfarin on the schedule that he has been given, the medication’s effectiveness may be jeopardized. It is easy to mix up the doses especially with a varying dosing schedule as HM has with Warfarin. HM’s behavior could also increase the risk of him bleeding if he is injured. He should use precaution when shaving, brushing his teeth, and doing any other activities that could cause him to bleed as Warfarin is an anti-coagulant, which means it would be difficult to stop the bleeding if he does cut himself. HM should wear a medical alert bracelet that tells others he is taking Warfarin (Mayo Clinic, 2018). However, it is not just behavioral characteristics that could cause HM problems with the mix of medications he is taking.

Changes that Might Impact Recommended Drug Therapy

None of the prescribed medications--Warfarin, Metformin, Glyburide or Atenolol—should be taken with aspirin; however, HM has been advised to take an aspirin every day. According to Drugs.com (2019), Glyburide and Metformin should not be taken together unless there are special circumstances. A moderate interaction could result (Drugs.com, 2019). With the current issues about which HM complains may indicate some interactions or side effects of the medication he takes. Drugs.com (2019) says that Glyburide and Metformin should not be taken together, but Healthline (2019) talks about a pill that has the two medications combined. However, it only comes in a generic version. Healthline (2019) also warns that the Glyburide-Metformin pill has a black box warning, which is the highest level of precaution there is. “Glyburide/metformin can cause lactic acidosis. . . . Lactic acidosis is a rare problem that happens when oxygen levels in your body drop. This leads to a buildup of lactic acid in your bloodstream. The condition can sometimes be fatal. Your risk of lactic acidosis may be higher if you have diabetes with kidney damage or heart failure” (Healthline, 2019). Since HM is a diabetic, there is further precaution for him taking the two medications together. He should be given a new prescription in exchange for one or both of the oral diabetes medications he takes so that drug interactions are not a concern.

The fact that HM takes aspirin with all of the medications and that there is a side effect of arrythmia may account for the atrial fibrillation and a transient ischemic attacks he has had. Also, Atenolol should not be given to patients who have ischemic heart disease. Drugs.com (2019) says there is a major risk factor if people with ischemic heart disease are given Atenolol or other beta blockers. “Exacerbation of angina, myocardial infarction and ventricular arrhythmias have been reported in patients with coronary artery disease following abrupt withdrawal of therapy” (Drugs.com, 2019). Atenolol can also have interactions with HM’s diabetes and hypertension. Atenolol can “mask symptoms of hypoglycemia such as tremors, tachycardia and blood pressure changes” (Drugs.com, 2019). Atenolol can also raise cholesterol levels, which is counteractive for HM who has hyperlipidemia. HM could accidently miss a dose and have any one of these reactions. The entire medication regime that HM has been prescribed should be revised.