Block 10 Pharmacology

Question 1

Enalapril, Lisinopril, Ramipril, and Captopril

Answer 1

ACE inhibitor

Uses: treatment of hypertension, congestive heart failure, nephropathy

MOA: Inhibits ACE used in the conversion of ATI to ATII which normally works to increase BP

Question 2

Amiloride

Answer 2

Potassium sparing diuretic

Uses: Hypertension and heart failure

MOA: Inhibit K/Na exchange in DCT and collecting duct which reduces Na reabsorption and K+ excretion -> more water loss in urine

note: can cause HYPERKALEMIA and not to be used with ACEi

Question 3

Furosemide

Answer 3

Loop diuretic

Uses: Hypertension, pulmonary oedema and HF

MOA: Inhibit the Na/K/Cl- symporter in ASC loop of Henle -> inhibiting reabsorption of these ions causes increased water loss

Note: can cause HYPOKALEMIA

Question 4

Bendroflumethiazide

Answer 4

Thiazide diuretic

Uses: Hypertension, oedema (caused by heart failure, liver failure or kidney failure)

MOA: Inhibit the Na/Cl- symporter thereby inhibiting Na/Cl reabsorption. Leads to increased water excretion

Note: can cause HYPOKALEMIA

Question 5

Chlortalidone

Answer 5

Thiazide-like diuretic

Uses: Hypertension, mild HF, stones

MOA: Inhibits Na+/Cl- channel on the distal convoluted tube

note: can cause HYPOKALEMIA

Question 6

Doxazosin

Answer 6

Alpha-1 adrenoceptor antagonist

Uses: Hypertension, aid with urination in BPH (relaxes SMCs in prostate)

MOA: Binds to a-1 receptors on SMC in vessels causing vasodilation -> decreases vascular resistance and BP

Question 7

Spironolactone

Answer 7

Potassium sparing diuretics and aldosterone receptor antagonist (MRA)

Uses: Hypertension and HF

MOA: Inhibit K/Na exchange in DCT and collecting duct which reduces Na reabsorption and K+ excretion -> more water loss in urine

note: can cause HYPERKALEMIA and not to be used with ACEi

Question 8

Acetazolamide

Answer 8

Carbonic anhydrase inhibitor (diuretic)

Uses: Glaucoma, Epilepsy, Altitude sickness

MOA: Inhibit the enzyme carbonic anhydrase -> less Na+ reabsorption and more water loss

Question 9

Cisplatin

Answer 9

DNA cross-linker (platinum-based chemotherapy drug)

Uses: Cross-links DNA and triggers apoptosis

MOA: Used in sarcomas, carcinomas, lymphomas, bladder cancer, cervical cancer and germ cell tumours

Question 10

Methotrexate

Answer 10

Folate antagonist
DMARD (disease modifying anti-rheumatic drug)

Uses: RA (low dose) and cancer in larger doses (as it is cytotoxic)

MOA: Antifolate -> Competitive inhibition of DHFR (enzyme needed to make tetrahydrofolate that’s needed in DNA synthesis of purines)
-anti-inflammatory effect and affects immunoregulatory pathways leading to immunosuppression

Question 11

Phenobarbital

Answer 11

Antiepileptic (barbiturate) -> GABA agonist

Uses: Epilepsy (Tonic-clonic and simple partial seizures)

MOA: bind GABA receptor as agonists at barbiturate site on POST-SM and cause Cl- influx and cause hyperpolarisation -> inhibit neuronal firing

Question 12

Pethidine

Answer 12

Opioid receptor agonist (analgesic)

Uses: Moderate to severe pain. Does not reduce uterine contractions so favoured for labour pain.

MOA: Activates μ opioid receptors in the brain and spinal cord to inhibit pain transmission.

Question 13

Mannitol

Answer 13

Osmotic diuretic

Uses: Glaucoma, Cerebral oedema, decrease ICP prior/during neurosurgery

MOA: freely filtered into the filtrate and not reabsorbed so increases osmolarity of filtrate (hyperosmolar) facilitating excretion of water

Use: Cerebral oedema

Question 14

Amphetamine

Answer 14

A non-catecholamine sympathomimetic

Uses: Vasoconstriction (increase BP), Inhibits Nora release, Increase HR
CNS Stimulant (arousal, alertness, concentration. Euphoria/excitement)
Stereotyped behaviour. Anxiety. Reduced appetite. Sympathomimetic actions: tachycardia, pupillary dilation, etc.

MOA: mimicks the structures of the catecholamine NTs (noradrenaline and dopamine) so able to modulate monoamine release, reuptake, inhibits MAO and able to bind 5-HT receptors directly

Question 15

Warfarin

Answer 15

Vitamin K antagonist (anticoagulant)

Uses: prevention and treatment of DVT, thromboembolism, and pulmonary embolism. + prevention of stroke in those with AF

MOA: inhibits vitamin K reductase needed for vit K synthesis -> vit K important in production of coagulation fators 2/7/9/10

note: Warfarin can cross the placental barrier during pregnancy-> can cause foetal bleeding, spontaneous abortion, and neonatal death