Case Study 3: Beta-Adrenergic Antagonists

1570 Words7 Pages
Case Study 3: Beta-Adrenergic Antagonists Cathy Lopez is a 33-year-old Hispanic American who visits the local walk in clinic complaining that she had a severe headache, which was unilateral. She states I used to take something every day to prevent headaches, but I have not needed it lately. She states, “I just moved and started a new job. Can you prescribe me anything to prevent these headaches?” Ms. Lopez’s headaches in the past were treated with a prophylaxis, which indicate she has migraines. The treatment to prevent migraines is the use of beta-adrenergic antagonists. 1. What will you prescribe for Ms. Lopez? a. Timolol 10mg bid PO 2. What are the pharmacokinetics: (Timolol, 2015) a. Use – Beta-blocker, migraine/headache, prevention of further MI (Lexicorp, 2015) b. Mechanism of action – non-selectively antagonizes beta-1 and beta-2 adrenergic receptors c. Well absorbed when given orally (Woo & Wynne, 2012). d. Metabolizes in the liver, CYP450, 2D6 substrate e. Excretion – urine f. Half-life 2 – 4 hours 3. What are the pharmacodynamics: a. ‘Blockade of beta-adrenergic receptors produces significant action on the cardiovascular, renal and respiratory systems and on the eye. This blockade also results in metabolic and endocrine effects’ (Woo & Wynne, 2012, p. 184). b. Clinical pharmacology studies have confirmed the beta-adrenergic blocking activity as shown by: (Micromedex, 2015). i. Changes in resting heart rate and response of heart rate to changes in posture; ii. Inhibition of isoproterenol-induced tachycardia; iii. Alteration of the response to the Valsalva maneuver and amyl nitrite administration; iv. Reduction of heart rate and blood pressure changes on exercise c. Timolol decreases the positive chronotropic, positive inotropic, bronchodilator, and vasodilator responses caused by beta-adrenergic receptor agonists. i. The

More about Case Study 3: Beta-Adrenergic Antagonists

Open Document