Pharmacology 1 Flashcards
What does ADME stand for?
Absorption, distribution, metabolism, excretion
What are the two principle ways in which drugs are excreted from the body?
1) Renal system
2) Biliary system
Give the class of each drug;
- Atenolol
- Bendroflumethiazide
- Bumetanide
- Diltiazem
- Lansoprazole
- Prednisolone
- Ramipril
- Salbutamol
- Simvastatin
- Warfarin
- Atenolol → beta blocker (b2 antagonist)
- Bendroflumethiazide → thiazide diuretic
- Bumetanide → loop diuretic
- Diltiazem → calcium channel blocker
- Lansoprazole → PPI
- Prednisolone → catabolic steroid
- Ramipril → ACE inhibitor
- Salbutamol → B2 agonist
- Simvastatin → HMG co-reductase inhibitor
- Warfarin → vitamin K antagonist
Which drug is the most likely to cause harm from the following;
- Atenolol
- Bendroflumethiazide
- Bumetanide
- Diltiazem
- Lansoprazole
- Prednisolone
- Ramipril
- Salbutamol
- Simvastatin
- Warfarin
Warfarin
What harm can warfarin cause?
- Can cause coumarin induced skin necrosis; skin and subcutaneous tissue necrosis occur due to acquired protein C deficiency following treatment with vitamin K anticoagulants
- Nosebleeds, bleeding gums, heavy periods, bruising
Which 2 drugs counteract each other from the following;
- Atenolol
- Bendroflumethiazide
- Bumetanide
- Diltiazem
- Lansoprazole
- Prednisolone
- Ramipril
- Salbutamol
- Simvastatin
- Warfarin
Atenolol and salbutamol
Which drug is the most associated with long-term side effects from the following;
- Atenolol
- Bendroflumethiazide
- Bumetanide
- Diltiazem
- Lansoprazole
- Prednisolone
- Ramipril
- Salbutamol
- Simvastatin
- Warfarin
Prednisolone
What are potential long-term side effects from prednisolone?
Osteoporosis, poorly controlled diabetes due to high blood sugar, glaucoma, skin thinning, slower wound healing
Which 3 drugs act on enzymatic pathways?
- Atenolol
- Bendroflumethiazide
- Bumetanide
- Diltiazem
- Lansoprazole
- Prednisolone
- Ramipril
- Salbutamol
- Simvastatin
- Warfarin
- Warfarin (acts on enzyme associated with vit K production)
- Ramipril (ACE inhibitor)
- Simvastatin (HMG co-reductase inhibitor)
Which class of drugs is most commonly prescribed in the UK?
Statins
What is the mechanism of action of atenolol?
Blocks the release of catecholamines (stress hormones) adrenaline and noradrenaline at B1 adrenergic receptors in certain parts of the body
This decreases sympathetic activity of the heart → decreases conduction through the AV node
Also reduces renin secretion which blocks formation of angiotensin II
What are the principle effects of beta blockers (beta-adrenergic blockers)?
- Slow heart rate
- Reduce blood pressure (by reducing force at which blood is pumped around the body)
- Cardioprotective (protects against recurrent heart attacks)
Some beta blockers are cardio-selective. What does this mean?
That their effects are predominantly on the heart, and they have little effect on beta-adrenergic receptors elsewhere in the body.
Some beta-blockers are non-cardio-selective. What side effects can this cause?
These also have an effect on adrenergic receptors in the lungs and peripheral circulation.
- Can cause bronchoconstriction (dangerous in asthma).
- Can cause constriction of peripheral circulation (dangerous in peripheral vascular disease)
Indications for beta-blockers?
- Angina (the reduction in HR reduces the oxygen requirements for the heart)
- Tachyarrhythmias e.g. fast AF (to slow the HR)
- Hypertension
- Beneficial effects in patients with heart failure
- Complications of MI e.g. LV systolic dysfunction
- Supraventricular tachycardias
Contraindications for beta blockers?
- Patients with bradycardia
- Patients with hypotension
- Patients with diabetes (can mask hypoglycaemia signs)
In addition, non cardio-selective beta blockers are contraindicated in:
- Patients with peripheral vascular disease → cause constriction of peripheral circulation
- Patients with asthma → cause bronchial constriction
Common side effects of atenolol?
- GI upset: N&V, constipation, diarrhoea, abdominal pain
- Dizziness, syncope, fatigue (bradycardia)
- Cold fingers and toes
- Rash → concern
How often should atenolol be taken?
Daily
Which side effects should cause a patient to call 999/seek medical help when taking atenolol?
- Signs of allergic reaction: rash, wheezing, swelling of face/tongue etc
- Signs of cardiac issues: SOB, chest pain, irregular heart beat, swollen ankles or legs
- Signs of respiratory disease
Describe appropriate treatment cessation of atenolol. Why is it important to not stop taking it suddenly?
- Avoid abrupt withdrawal, especially in heart disease patients as may cause rebound worsening of myocardial ischaemia
- Encourage gradual reduction
What are the 3 major classes of diuretic medications?
- Loop
- Thiazide
- Potassium-sparing
When would combination diuretic therapy be considered?
May be effective in patients with oedema resistant to treatment with one diuretics.
Describe the mechanism of action of thiazide diuretics (e.g. bendroflumethiazide)
Inhibits the sodium/chloride cotransporter located in the distal convoluted tubule of a nephron. This inhibits sodium uptake so increases the excretion of sodium and water.
What is the primary effect of diuretics?
Increase fluid excretion, ‘water tablets’
What are the 2 major indications for thiazide diuretics?
- Oedema
- Hypertension
Give some contraindications for thiazide diuretics
- Addison’s disease (underactive adrenal glands)
- Hyponatraemia, hypokalaemia
- Hypercalcaemia
- Symptomatic hyperuricaemia
- Previous allergic reaction to drug
- Liver problems
What time of day is it ideal to take diuretics?
In the morning (taking in evening can cause needing to wee in night)
Potential side effects of thiazide diuretics?
- Needing to urinate more often
- Dehydration (feeling thirsty with a dry mouth)
- Mild stomach upset: pain, constipation, diarrhoea, N&V
- Deranged electrolytes levels (hypokalaemia)
- Hypovolaemia
- Allergic reaction
How are thiazide diuretics excreted?
Renally (be careful in renal failure patients)
What type of diuretic is bumetanide?
Loop diuretic (think… furosemide)
What are the 2 major indications for loop diuretics?
- Pulmonary oedema due to LVF and chronic heart failure (or CKD)
- Hypertension
Which type of diuretic would be used to treat a pulmonary oedema 2ary to LVF and chronic heart failure?
Loop diuretics
What is the mechanism of action of loop diuretics?
- Inhibit the Na+/K+/2Cl co-transporter in the loop of Henle (in the kidney) which reduces the Na, Cl & K reabsorption
- This leads to increased loss in the urine (water follows this so excess water is lost)
- Less fluid remains in bloodstream (eases symptoms of oedema)
Contraindications for loop diuretics (e.g. bumetanide)?
- Anuria
- Hypokalaemia/hyponatraemia
- Hypotension
- Allergic reaction to drug
- Liver disease
Common side effects of loop diuretics?
- Urinating more frequently
- Symptoms of dehydration: feeling thirsty and dry mouth
- Weight loss (as body loses water)
- Headaches
- Confusion/dizziness
- Muscle cramps/weakness
- Electrolyte imbalance
- Hypotension
Serious side effects of loop diuretics?
- Ringing in ears (tinnitus) or loss of hearing
- Unexplained bruising or bleeding
What time of day should patients take loop diuretics?
In morning (not after 4pm)
