Patient case studies Applied Pharmacology: What is the role of the CYP2D6 in the drugs’ metabolism in general?

Patient case studies Applied Pharmacology

1. A patient is taking Paroxetine and presents to A&E with tremor, tachycardia, hypertension
and high temperature. After a genetic screening, the variant CYP2D6*4 is identified. Discuss:

• What is Paroxetine and how does it work (mechanism and clinical use)?
• What is the role of the CYP2D6 in the drugs’ metabolism in general?
• What is the metabolic pathway of Paroxetine and how is it affected by the genetic variant described in this case study?
• What is the resulting alteration in the blood levels of Paroxetine?
• What is the link between the altered blood levels of Paroxetine and the signs and symptoms reported?

2. A 20 year old woman with history of poorly controlled asthma presents to the A&E with severe shortness of breath and audible respiratory wheezing. She has normal blood pressure but she is pale. She uses terbutaline inhaler when needed but now the inhaler isn’t helping
• What emergency drug should be administered?
• Discuss: the indications, side-effects and mechanism of action of the proposed drug
• What long-term therapy should follow, after she is stabilized?
• Discuss: the indications, side-effects and mechanism of action of the proposed therapy for long-term management

(750 words each)