The document contains 6 clinical case scenarios involving drug-drug interactions and medication errors. Each case provides details about a patient, their medications, adverse effects experienced, and asks 3 questions related to analyzing and addressing the clinical situation. The cases cover topics like interactions between sildenafil and nitrates, tetracycline toxicity in a child, theophylline toxicity from cimetidine use, hypoglycemia from alcohol and sulfonylureas, Parkinsonism from phenothiazines, and lithium toxicity from thiazide diuretics.

1. Prescription audit

4. Question 1
• Critically analyse the following prescription and rewrite it
Dr Balu Joshi MBBS, MD
DMC Reg no 96631
NIT-3, Faridabad
Phone (clinic): xxxx Mobile :xxxxxxxx
Email : xxxxxxxxxxxxxx
14 January 2021
Name: Nishi Age/sex: 40 female
Address: H No 445, Model Town, New Delhi Mob: xxxxxxx email: xxxxxxxxx
Unit No. C-238567
Rx
NORFLOXACIN 400mg twice daily * 3days -6 tablets
PHENAZOPYRIDINE 100mg 2 tablets twice daily * 2-3 days -20 tablets
Dispensed
Date ------------ Pharmacist’s name ---------------
Pharmacy city --------------

5. Question 2
• Critically analyse the following prescription and rewrite it
Dr Balu Joshi MBBS, MD
DMC Reg no 96631
NIT-3, Faridabad
Phone (clinic): xxxx Mobile :xxxxxxxx
Email : xxxxxxxxxxxxxx
14 January 2021
Name: Sashi Age/sex: 35 male
Address: H No 445, Model Town, New Delhi Mob: xxxxxxx email: xxxxxxxxx
Unit No. C-238567
Rx
Tab Omeprazole 200mg 2 times a day
Tab Clarithromycin 500mg 2 times a day
Cap Amoxycillin 1g 3 times a day
All medicines to be taken 15-30 minutes before meals for one week.
Avoid alcohol, smoking, stress, caffeinated drinks.
Signature
Name and Reg No

6. Question 3
• Critically analyse the following prescription and rewrite it
Dr Balu Joshi MBBS, MD
DMC Reg no 96631
NIT-3, Faridabad
Phone (clinic): xxxx Mobile :xxxxx
Email : xxxxxxxxxxxxxx
14 January 2021
Name: Tarun
Address: H No 445, Model Town, New Delhi
Unit No. C-238567
Rx
Tab WARFARIN 10mg once daily
Tab FLUCONAZOLE 50mg once daily
Signature
Name and Reg No
Dispensed
Date ------------ Pharmacist’s name ---------------
Pharmacy city --------------

7. Question 4
• Critically analyse the following prescription and rewrite it
Dr Balu Joshi MBBS, MD
DMC Reg no 96631
NIT-3, Faridabad
Phone (clinic): xxxx Mobile :xxxxxxxx
Email : xxxxxxxxxxxxxx
14 January 2021
Name: Nishi Age/sex: 40 female
Address: H No 445, Model Town, New Delhi Mob: xxxxxxx email: xxxxxxxxx
Unit No. C-238567
Tab METOPROLOL 50mg twice daily for 1 month
Tab VERAPAMIL 40mg thrice daily for 2 weeks
Signature
Name and Reg No
Dispensed
Date ------------ Pharmacist’s name ---------------
Pharmacy city --------------

8. Question 5
• Critically analyse the following prescription and rewrite it.
Date :14/01/2021
Name : Mr Kulwant Singh
Age : 47
Sex : M Occupation : Business executive Address : Mahim(Bombay)
Diagnosis : Status asthmaticus
Rx
Tab CETRIZINE 10mg stat
Injection PETHIDINE 10mg IM 6 hourly
Tab salbutamol 20mg TDS
Injection adrenaline hydrochloride 1:1000 iv, SOS

9. Question 6
• Critically analyse the following prescription and rewrite it.
Rx
• Injection L-DOPA 10mg iv stat
• Tab B COMPLEX 1 tab twice daily
• Tab BENZHEXOL HYDROCHLORIDE 2-5 mg initially and then dose increased to 300mg daily in
divided doses.
Signature
Dr. Balu Joshi
Reg No 52367

10. Clinical Problems

11. Question 1
• A 52 year old male was taking nitrates for angina for the last one year.
He was prescribed sildenafil for erectile dysfunction. On next day at
11pm he was admitted in ICU with aggravation of angina.
a. What happened to patient?
b. Which other drugs can lead to similar situation?
c. How can this be treated?

12. a. The patient has fatal hypotension because of the use of nitrates and
sildenafil (PDE-5 inhibitor) at once. Both these drugs are potent
vasodilators.
b. Antihypertensive drugs when used with nitrates can also lead to a
similar situation.
c. Fluid resuscitation, alpha-1 adrenergic agonists (Midodrine,
Methoxamine), Fludrocortisone.

15. Question 2
• A 4 year old male child diagnosed with mycoplasma pneumonia was
started on an antibiotic 250mg QID for 15 days. Later on, the child
developed brown discoloration and mottling of teeth.
a. Which antibiotic was given to him?
b. What is the effect of this dose and duration of treatment?
c. Suggestive an alternative antimicrobial agent.

16. a. Tetracycline
b. The high dose tetracycline when prescribed for a prolonged period
can get deposited in teeth and bones causing damage.
c. Macrolides are the treatment of choice

17. Question 3
• A 20 year old patient of bronchial asthma who was on theophylline
200mg TDS developed peptic ulcer for which Tab Cimetidine 300mg
and 10 ml of an antacid was given. One week later he developed
restlessness and tremors.
a) What is the cause of tremor?
b) What are the alternative regimens?
c) What other drugs produces such a condition?

18. a. Cimetidine is a microsomal enzyme inhibitor. Therefore, the
metabolism of theophylline was reduced leading to high
concentration in blood resulting in toxicity. Theophylline crosses
Blood brain barrier and is a CNS stimulant causing tremors, delirium
and convulsion at higher doses.
b. We can use proton pump inhibitor drugs like omeprazole,
lansoprazole.
c. Valproate, ketoconazole, ciprofloxacin, erythromycin, isoniazid
(INH).

19. Question 4
• A 55 year old man with NIDDM is controlled on Tab Tolbutamide. He
attends a cocktail party and after 2 hours he starts feeling unwell,
hungry, motor incoordination and abdominal discomfort.
a. Why did this happen?
b. What investigations would you like to do?
c. What is the treatment?

20. a. Alcohol intake inhibits metabolism or excretion of sulfonylureas like
tolbutamide. This increases the hypoglycaemic action of
tolbutamide leading to the symptoms.
b. Blood sugar
c. 5% dextrose infusion

21. Question 5
• Mr Sam is on phenothiazine therapy for his psychiatric illness and
develops parkinsonism during the course of treatment. He is
prescribed L-Dopa 250mg QID, the patient is not relieved and so the
dose is increased to 750mg QID. Still the patient was not benefitted.
a. Why he developed parkinsonism?
b. Why he is not benefitted?
c. What alternative would you suggest to control his problem?

22. a. Drug induced parkinsonism due to D2 receptor blockade
b. L-Dopa cannot act because of D2 receptor blockade
c. Centrally acting anti-cholinergic drug (Benzhexole)

23. Question 6
• A 55 year old male patient was stable on lithium for the last 6
months. He was prescribed chlorthiazide for CHF. After 1 month, he
complained of persistent nausea/vomiting and blurred vision.
a. What happened to the patient?
b. Which other drugs can lead to similar situation?
c. How this can be treated?

24. a. The patient has developed lithium toxicity.
b. ACE inhibitors, NSAIDs
c. Thiazides can be substituted with loop diuretics.