Transcript P Drug Exercises

P Drug Exercises
Dr Navneet Kaur
P-Drug Concept
• P-drugs are the drugs you have chosen to prescribe
regularly, and with whom you have become familiar.
• The P-drug concept is more than just the name of a
pharmacological substance, it also includes the dosage
form, dosage schedule and duration of treatment.
Personal
Priority
Preferred
Choice of P-drug
(STEP Criteria)
A P-drug is selected depending upon the following criteria:
• Safety: possible adverse effects.
• Tolerability: suitability for a patient.
• Efficacy: drug profile.
• Price: always look at the total cost of treatment rather
than the cost per unit.
Process of Choosing a P Drug
• Define the Diagnosis
• Set Therapeutic Objective
• Make inventory of effective groups of drugs
• Choose an Effective Group
• Choose a P drug
Exercise 1
• A 40 years old man moderately obese is a diagnosed
case of hypertension with BP 146/94. ECG shows left
ventricular enlargement. Choose the effective P Drug.
Example of selecting a P-drug: angina pectoris
1. Define the diagnosis
Stage I hypertension
2. Specify therapeutic objective
Prolong useful life by preventing cardiovascular problems by reducing
BP < 140/90
iii. Make inventory of effective groups
ACE inhibitors
AT receptor antagonists
Diuretics
ß-blockers
Calcium channel blockers
iv. Choose a group according to criteria
Efficacy Safety Suitability Cost
ACE inhibitors(tablet)
++
++
++
B- blockers
+
+
+
-
Diuretics
+
+
++
+
+
+
CCB
+
+
Choose a P-drug
Efficacy
Captopril(tablet) +
Safety
±
Suitability
-
Cost
+
Ramipril(tablet)
+
++
++
+
Lisinopril(tablet)
+
+
+
±
Conclusion
• Active substance, dosage form: Ramipril, tablet 5 mg
• Dosage schedule: 1 tablet OD
• Duration: length of monitoring interval
Exercise 2
A patients is a 60-year old man, with no previous medical history. During the
last month he has had several attacks of suffocating chest pain, which began
during physical labour and disappeared quickly after he stopped. He has not
smoked for four years. Auscultation reveals a murmur over the right carotid
artery and the right femoral artery. Physical examination reveals no other
abnormalities. Blood pressure is 130/85, pulse 78 regular, and body weight is
normal.
Example of selecting a P-drug
i. Define the diagnosis
Stable angina pectoris, caused by a partial occlusion of coronary artery
ii. Specify therapeutic objective
Stop an attack as soon as possible
Reduce myocardial oxygen need by decreasing preload, contractility, heart rate
or afterload
iii. Make inventory of effective groups
Nitrates
ß-blockers
Calcium channel blockers
iv. Choose a group according to criteria
Nitrates (tablet)
Efficacy Safety Suitability
+
±
++
B-blockers (injection)
+
±
CCB (injection)
+
±
-
Cost
+
-
-
-
Choose a P-drug
efficacy
GTN(tablet) +
safety
±
suitability
+
cost
+
(spray)
+
±
(+)
-
IDN(tablet)
+
±
+
±
IMN(tablet)
+
±
+
±
Conclusion
• Active substance, dosage form: glyceryl trinitrate, S/L tablet 1 mg
• Dosage schedule: 1 tablet as needed; second tablet if pain persists
• Duration: length of monitoring interval
Exercise 3
• A 50 year-old male patient complains of bloody, mucoid stools
and abdominal pain. There is no history of alcohol abuse. You
have diagnosed it as a case of acute amoebic dysentery.
Choose an appropriate drug and mention its dosage schedule
and duration of treatment.
• Step 1: Define the diagnosis
 Amoebiasis is a protozoal infection caused by the ingestion of
amoebic cysts of Entamoeba histolytica
• Step 2: Specify the therapeutic objective
 To treat the signs and symptoms
 Eradicate the disease and prevent transmission of the disease
 Prevent further complications.
• Step 3: Make an inventory of effective groups of drugs
 Nitroimidazoles [metronidazole, tinidazole, secnidazole,ornidazole]
 Alkaloids [emetine, dehydroemetine]
 Amide [diloxanide furoate]
 8-Hydroxyquinolines [iodochlorohydroxyquin, diiodohydroxyquin]
 Antibiotics [tetracyclines, paromomycin]
Step 4: Choose an effective group according to criteria
Inventory of effective groups of drugs
Group
Efficacy
Safety
Nitroimidazoles
++
+++
Suitability
Cost
+++
++
-
+
Relatively frequent
but nonserious
Alkaloids
Amides
+/-
--- (highly
+
++(very well
toxic)
+
tolerated)
Antibiotics
8-Hydroxyquinolines
+
+
- (well tolerable)
+
+
Total
Score
Efficacy
Safety
Suitability
Cost
Metronidazole
No difference
No difference
No difference
Rs 6.75
Tinidazole
No difference
No difference
No difference
Rs 12.65
Secnidazole
No difference
No difference
No difference
Rs 26.40
Ornidazole
No difference
No difference
No difference
Rs 39
Satranidazole
No difference
Better
tolerabiity,
absence of
neurological
side effects
Can be preferred in Rs 40
patients with
susceptible
neurological
symptoms
Step 5: Choose a P-drug
• Choose an active substance and a dosage form
Metronidazole 400 mg followed by a diloxanide furoate 500 mg to prevent
carrier state
• Choose a standard dosage schedule
400 mg three times a day
• Choose a standard duration of treatment
Tablet metronidazole 400 mg three times a day for five days followed by Tablet
Diloxanide furoate 500 mg three times a day for 10 days.
Exercise
• Verify in each of these cases whether the active
substance and dosage form of your P -drug is suitable
(effective, safe) for this patient.
• Man, 45 years. Suffers from asthma. Uses salbutamol inhaler. A
few weeks ago you diagnosed essential hypertension (145/100
on various occasions).
• You advised a low-salt diet, but blood pressure remains high.
• You decide to add a drug to your treatment.
• Your P-drug for hypertension in patients under 50  Tab
atenolol 50 mg a day
• Woman, 22 years, 2 months pregnant. Large abscess on her right
forearm. You conclude that she will need surgery fast, but in the
meantime you want to relieve the pain. Your P-drug for common
pain is acetylsalicylic acid (aspirin) tablets
• Boy, 4 years. Cough and fever of 39.5 C. Diagnosis: pneumonia.
One of your P-drugs for pneumonia is tetracycline tablets.
Step 3B: Is the standard dosage schedule
suitable for this patient?
• Woman, 43 years. History of insulin dependent diabetes for 26 years.
Stable on treatment with two daily doses of neutral insulin, 20 IU and 30
IU. Recently mild hypertension was diagnosed, and diet and general advice
have not been sufficiently effective. You would like to treat this condition
with a beta-blocker. Your P-drug is atenolol 50 mg once daily.
• Woman, 50 years. Chronic rheumatic disease, treated with your P-drug,
indometacin 50 mg, 3 times daily plus a 50 mg suppository at night. She
complains of pain early in the morning
Step 3C: Is the standard duration of treatment suitable
for this patient
• Woman, 62 years. Angina pectoris, waiting for referral to a
specialist. R/glyceryl trinitrate 5 mg, as necessary 1 tablet
sublingual, give 60 tablets.
• Woman, 24 years. Feels weak and looks a bit anaemic. No Hb
result available. R/ferrous sulfate 60 mg tablets, 1 tablet three
times daily, give 30 tablets