Case study:
FR, aged 86, has had urinary urge incontinence for many years. His condition is managed with oral doses of the antimuscarinic agent oxybutynin at night. FR has also had carpal tunnel syndrome, which is a form of peripheral neuropathy caused by increased pressure on the median nerve that normally allows feeling and movement to the hand. He takes amitriptyline, a tricyclic antidepressant to treat the peripheral neuropathy. Since the onset of spring, he has experienced severe hay fever from the pollens and dander. He goes to his local pharmacy and purchases diphenhydramine tablets. Over recent days, he has felt increasingly dizzy, light-headed and constipated. He organises an appointment with his doctor.
Questions:
Q1. Explain the mechanisms of action of oxybutynin, amitriptyline and diphenhydramine in managing FR's conditions.
Q2. What is happening to FR to make him feel increasingly dizzy, light-headed and constipated?
References
Bullock, S 2017, Fundamentals of Pharmacology, 8th edn, Pearson Australia. ISBN: 9781442563100