Patient case studies Applied Pharmacology
Case Studies (up to 2300 words):
Read the following three case studies and answer all questions:
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 (can you identify the syndrome)?
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
A 57 year old female presents to the GP with palpitations on and off for 4 months. The patient describes the palpitations as feeling like missed beats, flutters, and a racing heart usually of sudden onset. Her medical/health history reveals that she has hypertension (BP 152/94 mmHg), she is a mild diabetic, and also suffers from gastro-oesophageal reflux disease (GORD). She has a BMI of 38. Her medications include Cilazapril and Hydrochlorothiazide, and Omeprazole.
A blood test revealed the following:
| Test | Result |
| FBC (full blood count) | Normal |
| TFTs (Thyroid function tests) | TSH 3.2 (0.6-4.5) |
| U+E (urea & electrolytes) | K+ 3.2mmol/l (3.5-5.0 mmol/l) |
| Magnesium 0.68mmol/l (0.75-1.25 mmol/l) | |
| Urea 7.8mmol/l (3.6-7.1 mmol/l) | |
| Creatinine 118mcmol/l (52.2-91.9 mcmol/l) | |
| Random glucose 9.8 mmol/l (3.0-7.8 mmol/l) |
Normal ranges are shown in the table between brackets.
Analyse this case using a critical thinking approach as outlined below:
Gather, analyse and interpret the relevant medical and pharmacological information the clinician needs before treating this patient. (Assessment)
What are the relevant assumptions you have about this case, and what investigations would you undertake to confirm these assumptions? Would you check the levels of any other electrolytes?
Devise a care plan – what are the possible interventions/drugs that could be used to treat this patient? Consider the implications and consequences of the possible interventions and devise a ‘complete’ care plan (short & long term).