B8

Question 1

Glizazide

Answer 1

Class = Sulphonylurea

An oral hypoglycemic agent which is rapidly absorbed and completely metabolized.

MoA: Sulfonylureas likely bind to ATP-sensitive potassium-channel receptors on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Depolarization stimulates calcium ion influx through voltage-sensitive calcium channels, raising intracellular concentrations of calcium ions, which induces the secretion, or exocytosis, of insulin.

Question 2

Repaglinide

Answer 2

It belongs to the meglitinide class of short-acting insulin secretagogues, which act by binding to β cells of the pancreas to stimulate insulin release.

Use: Oral antihyperglycemic agent. Used to treat non-insulin dependent diabetes mellitus,

Question 3

Glucagon

Answer 3

MoA: Endogenous substance normally released from pancreatic alpha cells when INSULIN levels are low.
The main effect is as an agonist at glucagon receptors (GR) in the liver. Activation of these receptors sets up a second messenger cascade involving cAMP – PKA – PPK and finally activation of glycogen phosphorylase. This promotes the metabolism of glycogen into glucose which is then released into the bloodstream.

Question 4

Insulin

Answer 4

The body’s main, endogenous hypoglycemic agent.

Released from pancreatic alpha cells in response to elevated blood sugar.

MoA: Acts via the insulin receptor (IR) to control a vast range of processes in almost all metabolically active cells in the body. The second messenger pathways activated are extremely numerous and complex.

Effects: The main effects are the absorption of glucose into metabolising tissues and the subsequent promotion of glycolysis (converting glucose into useable energy (ATP) and storing of glucose for future use as glycogen (glycogenesis).

Question 5

Metformin

Answer 5

Biguanide antihyperglycemic agent

MoA: Differ from other classes of oral antihyperglycemic agents. Metformin decreases blood glucose levels by decreasing hepatic glucose production, decreasing intestinal absorption of glucose, and improving insulin sensitivity by increasing peripheral glucose uptake and utilisation

Use: Used for treating non-insulin-dependent diabetes mellitus (NIDDM). It improves glycemic control by decreasing hepatic glucose production, decreasing glucose absorption and increasing insulin-mediated glucose uptake.

Question 6

Octreotide

Answer 6

Octreotide is the acetate salt of a cyclic octapeptide. It is a long-acting octapeptide with pharmacologic properties mimicking those of the natural hormone somatostatin.

Use: Octreotide exerts pharmacologic actions similar to the natural hormone, somatostatin. It is an even more potent inhibitor of growth hormone, glucagon, and insulin than somatostatin

MoA: Octreotide binds to somatostatin receptors. These receptors are coupled via pertussis toxin sensitive G proteins which lead to inhibition of adenylyl cyclase.

Question 7

Pancreatin

Answer 7

Pancrelipase is an enzyme mixture isolated from porcine or bovine pancreas, sometimes called pancreatin. It contains 3 enzymes: amylase, lipase, and a protease (chymotrypsin).

Question 8

Pioglitazone

Answer 8

Thiazolidinedione

MoA: An agonist at peroxisome proliferator-activated receptor gamma nuclear receptor (PPAR-γ).

Reduces insulin resistance in metabolically active tissues (i.e. increases glucose absorption, storage and conversion into ATP) and prevents glucose release from the liver

Question 9

Acarbose

Answer 9

An alpha-glucosidase inhibitor

MoA: Alpha glucosidase is present in the gut and is essential for breaking down complex carbohydrates (i.e. starch) into glucose. Thus less glucose is released into the hepatic portal vein following a meal

Question 10

Exenatide

Answer 10

Glucagon-like peptide-1 receptor (GLP1R) agonists.

Exenatide is a functional analog of the human incretin.

MoA: Incretins enhance glucose-dependent insulin secretion and exhibit other antihyperglycemic actions following their release into the circulation from the gut.

Question 11

Liraglutide

Answer 11

Glucagon-like peptide-1 receptor (GLP1R) agonists

Victoza contains liraglutide, an analog of human GLP-1 and acts as a GLP-1 receptor agonist

Question 12

Sitagliptin

Answer 12

Sitagliptin is a new oral hypoglycemic (anti-diabetic drug) of the new dipeptidyl peptidase-4 (DPP-4) inhibitor class of drugs.

MoA: This enzyme-inhibiting drug is to be used either alone or in combination with metformin or a thiazolidinedione for control of type 2 diabetes mellitus.

The drug works to competitively inhibit a protein/enzyme, dipeptidyl peptidase 4 (DPP-4), that results in an increased amount of active incretins (GLP-1 and GIP), reduced amount of release of glucagon (diminishes its release) and increased release of insulin.

Use: Hypoglycemic (anti-diabetic drug)

Question 13

Ipragliflozin

Answer 13

Ipragliflozin is under investigation in Type 2 Diabetes and Diabetes Mellitus, Type 2.

MoA: Sodium-glucose transport protein 2 (SGLT2) antagonist

Question 14

Cabergoline + Bromocriptine

Answer 14

Dopamine receptor agonist

MoA: Some effect on serotonin receptors. Dopamine released from hypothalamus acts on D2 receptors in pituitary to decrease endocrine secretion.

All areas of pituitary affected: Anterior pituitary (Thyroid stimulating hormone (TSH), growth hormone (GH), Adrenocorticotropic hormone (ACTH), prolactin, lutenising hormone (LH), follicle stimulating hormone (FSH)); Intermediate pituitary (Melanocyte stimulating hormone (MSH)); Posterior pituitary (antidiuretic hormone (ADH) also called vasopressin, oxytocin).

Question 15

Metoclopramide

Answer 15

Dopamine antagonist

MoA: Dopamine D2R antagonist. Some effect on serotonin receptors, particularly 5HT3R.

Inhibits the effect of hypothalamic dopamine release on the pituitary gland thus increasing endocrine secretion

Question 16

Carbimazole

Answer 16

An imidazole antithyroid agent.

A pro-drug taken orally and metabolised in the liver to the active metabolite methimazole.

MoA: Metabolized to Methimazole by liver. Methimazole inhibits thyroid peroxidase, thus reducing iodination of the hormone precursor thyroglobulin and reducing levels of thyroid hormones triiodothyronine (T3) and thyroxine (T4).

Question 17

Levothyroxine

Answer 17

A synthetic hormone

The major hormone derived from the thyroid gland.

Use: Full agonist at thyroxine (T4) receptors. Thus mimics the effects of thyroxine release at the thyroid hormone receptor increasing cardiac output, ventilation rate, basal metabolic rate, bone growth, neuronal maturation and endometrial thickening.

Question 18

Protirelin

Answer 18

Protirelin is the pharmaceutically available synthetic analogue of the endogenous peptide thyrotropin-releasing hormone (TRH).

It is a tri-peptide tropic hormone, released by the hypothalamus, that stimulates the release of Thyroid Stimulating Hormone (TSH) and prolactin from the anterior pituitary.

Use: Mimics the effect of TRH released from hypothalamus on TRHR in anterior pituitary, thus increasing the amount of TSH release and therefore promoting release of thyroid hormones.

Question 19

Clomiphene (Clomifene)

Answer 19

Triphenylethylene

MoA: Competitive partial agonist at oestrogen receptors (ER) in hypothalamus. Oestrogen receptor activation inhibits release of GnRH which, in turn, decreases the amount of LH and FSH released by the anterior pituitary.
Therefore binding to the oestrogen receptor produces little oestrogen-like effects (oestrogen being the endogenous, full agonist at oestrogen receptors) but occupies the receptor to prevent oestrogen binding. Net effect is a reduction in signalling via the oestrogen receptor and thus an increase in GnRH release and consequently and increase in LH and FSH levels.

Use: A triphenyl ethylene stilbene derivative which is an oestrogen agonist or antagonist depending on the target tissue. Clomiphene has both oestrogenic and anti-estrogenic properties.

Question 20

Desmopressin

Answer 20

Peptide

Synthetic ADH analogie

MoA: Adds to any endogenous, pituitary released ADH in the blood, binding to the same receptor (AVPR1, 2, 3) in target tissue to produce the same effect as the endogenous hormone (vasoconstriction of arterioles, gluconeogenesis in liver, ACTH release from pituitary, water reabsorbtion through aquaporin-2 channels in the kidney collecting duct).

Use: Vasoconstriction of arterioles, gluconeogenesis in liver, ACTH release from pituitary, water reabsorbtion through aquaporin-2 channels in the kidney collecting duct

Question 21

Goserelin

Answer 21

Goserelin is a synthetic hormone.

MoA: Super agonist at gonadotropin releasing hormone receptors (GnRHR). Super-agonists have higher efficacy than endogenous (full) agonists. I.e. they produce a greater effect when bound to the receptor than the natural agonist. Mimics the effects of GnRH release from the hypothalamus on anterior pituitary, increasing release of LH, FSH and other sex steroids.

Use: In men, it stops the production of the hormone testosterone, which may stimulate the growth of cancer cells. In women, goserelin decreases the production of the hormone estradiol (which may stimulate the growth of cancer cells) to levels similar to a postmenopausal state. When the medication is stopped, hormone levels return to normal.

Question 22

Octreotide

Answer 22

Octreotide is the acetate salt of a cyclic octapeptide. It is a long-acting octapeptide with pharmacologic properties mimicking those of the natural hormone somatostatin.

Somatostatin receptor agonist

Use: Full agonist at SST2 receptors, reducing endocrine release from the anterior pituitary.

Question 23

Exogenous oxytocin class

Answer 23

Synthetic 9 residue cyclic peptide

MoA: The hormone is prepared synthetically to avoid possible contamination with vasopressin (ADH) and other small polypeptides with biologic activity.

Use: Mimics the effects of endogenous release of oxytocin from posterior pituitary and hypothalamus thus promoting uterine contraction during labor, reduced post-partum hemorrhage, milk ‘let down’ during suckling, maternal behaviour, sexual arousal and social interaction.

Question 24

Carbetocin

Answer 24

Oxytocin analogue

Use: Control postpartum haemorrhage

Question 25

Atosiban

Answer 25

Atosiban is an inhibitor of the hormones oxytocin and vasopressin.

Use: Intravenous medication as a labour repressant (tocolytic) to halt premature labor.

Question 26

Somatropin

Answer 26

Synthetically produced human growth hormone. Full agonist at GH receptors.

Use: Treatment of dwarfism and growth failure, growth hormone (hGH) stimulates skeletal growth in pediatric patients with growth failure due to a lack of adequate secretion of endogenous GH.

Question 27

Tetracosactide

Answer 27

(also known as Cosyntropin) is a synthetic peptide that is identical to the 24-amino acid segment of adrenocorticotropic hormone.

ACTH (1-24), a segment similar in all species, contains the biological activity that stimulates production of corticosteroids in the adrenal cortex.

Use: Full agonist at ACTH receptors in the adrenal cortex, thus increasing levels of cortisol causing increased blood sugar, increased metabolism, immune suppression and reduced bone formation

Question 28

What do all the following drugs have in common?

• Orlistat
• Liraglutide
• Bupropion
• Lorcaserin
• Phentermine

Answer 28

Body mass control use

Question 29

Orlistat

Answer 29

Synthetic derivative of lipstatin.

MoA: Inhibits pancreatic lipases thus reducing the breakdown and absorption of fat in the diet.

Question 30

Liraglutide

Answer 30

GLP-1 analogue

It is a GLP1R agonist

MoA: Liraglutide is an acylated GLP-1 (Glucagon-Like Peptide-1) receptor agonist. Liraglutide upregulates intracellular cAMP resulting in the release of insulin given elevated blood glucose concentrations. Glucagon secretion is also decreased in a glucose-dependent fashion by liraglutide.

Question 31

Bupropion

Answer 31

Aminoketone drug

MoA:
o Mainly a Noradrenaline/Dopmaine reuptake inhibitor (NDRI) but also an antagonist of nicotinic acetylcholine receptors.

o An antidepressant but has some clinical effectiveness against obesity where over-eating owing to psychological issues is a major identified cause.

Use: The hydrochloride is available as an aid to smoking cessation treatment. A unicyclic, aminoketone antidepressant. Effective against obesity also.

Question 32

Lorcaserin

Answer 32

Benzazepine drug

Highly selective 5HT2C receptor agonist, is used for the treatment of obesity

MoA: It has been shown to reduce body weight and food intake in animal models of obesity, and it is thought that targeting the 5HT2C receptor may alter body weight by regulating satiety. Lorcaserin is marketed as a salt form called Belviq, which is lorcaserin hydrochloride.

Question 33

Phentermine

Answer 33

Amphetamine analogue

Phenylbutylamine drug

MoA: A CNS stimulant and sympathomimetic with actions and uses similar to those of dextroamphetamine. Agonist at trace amine associated receptors (TAAR1) where it promotes NA release.
Therefore a psychostimulant and appetite suppressant.

Use: It has been used most frequently in the treatment of obesity.

Question 34

Ethinylestradiol + Oestradiol

Answer 34

Nuclear hormone receptor agonist

Ethinylestradiol is a synthetic derivative of natural oestrogen oestradial

MoA: Both Oestradiol and Ethinylestradiol interact with the oestrogen receptor (Erα or Erβ) present on female organs, breasts, hypothalamus and pituitary gland. Upon ligand binding, the oestrogen receptor enters the nucleus, and regulates gene transcription.

Question 35

Testosterone

Answer 35

A steroid sex hormone

Use: Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase.

DHT binds to the same androgen receptor with greater affinity than T, so it has 2.5 times higher androgenic potency of T.

Question 36

Nandrolone

Answer 36

Anabolic steroid occurring naturally in the human body,

MoA: Nandrolone increases production and urinary excretion of erythropoietin. It may also have a direct action on bone marrow. Nandrolone binds to the androgen receptor to a greater degree than testosterone, but due to its inability to act on the muscle in ways unmediated by the receptor, has less overall effect on muscle growth.

Note: Nandrolone is unusual in that unlike most anabolic steroids, it is not broken down into the more reactive DHT by the enzyme 5α-reductase, but rather into a less effective product known as Dihydronandrolone

Question 37

Alprostadil

Answer 37

A synthetic version of prostaglandin

Prostaglandin receptor agonist

MoA: Alprostadil binds to the EP1 and EP2 receptors, leading to either an increase in cAMP and the activation of Protein Kinase A (PKA), or activation of Phospholipase C (PLC) depending on the receptor activated in the target cells.

Use: Alprostadil acts locally to relax the trabecular smooth muscle of the corpora cavernosa and the cavernosal arteries. Swelling, elongation, and rigidity of the penis result when arterial blood rapidly flows into the corpus cavernosum to expand the lacunar spaces. The entrapped blood reduces the venous blood outflow as sinusoids compress against the tunica albuginea

Question 38

Apomorphine

Answer 38

Morphine derivative

Dopamine D2 agonist

Use: By stimulating dopamine receptors, which helps improve motor function. This allows it to be used for the loss of control of body movements such as muscle stiffness, slow movements, or trouble moving associated with advanced Parkinson disease.

Question 39

Finasteride

Answer 39

An orally active testosterone 5-alpha reductase inhibitor

MoA: Type II 5a-reductase converts testosterone to DHT. DHT appears to be the principal androgen responsible for stimulation of prostatic growth. Inhibition of Type II 5a-reductase with Finasteride, results in significant decreases in serum and tissue DHT concentrations, minimal to moderate increases in serum testosterone concentration, and substantial increases in prostatic testosterone concentration.

Use:
 Decreases in DHT concentrations lead to a reduction in prostate size (approximately 20-30% after 6-24 months of continued therapy).
 Furthermore it is used as a surgical alternative for treatment of benign prostatic hyperplasia

Question 40

Goserelin

Answer 40

GnRH receptor agonist

Decapeptide analogue of luteinizing hormone-releasing hormone (LHRH

MoA: Goserelin acts as a potent inhibitor of pituitary gonadotropin secretion. It targets the Lutropin-choriogonadotropic hormone receptor and Gonadotropin-releasing hormone receptor, both of which are G protein coupled receptors. The result is sustained suppression of LH and serum testosterone levels, which is linked to a reduction in cancer cell proliferation. When the medication is stopped, hormone levels return to normal

Question 41

Sildenafil

Answer 41

Phosphodiesterase inhibitor
A phosphodiesterase type 5 (PDE5) inhibitor

Nitric oxide (NO) causes the dilation of blood vessels. Therefore inhibition of PDE5 by Sildenafil slows the breakdown of the cGMP and therefore maintains the effectiveness of NO.

Use: Vasodilator via NO maintenance. Sildenafil also is used for erectile dysfunction as inhibition of PDE5 in the corpus cavernosum located around the penis causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle

Question 42

Desogestrel / Etonogestrel / Levonorgestrel

Medroxyprogesterone acetate

Norethisterone

Answer 42

Progesterone nuclear hormone receptor agonist

Question 43

Desogestrel / Etonogestrel / Levonorgestrel

Answer 43

These drugs are used as female contraceptives.

MoA: They work by binding to the progesterone and oestrogen receptors present on the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Once bound to the receptor, progestins like desogestrel will slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH (luteinizing hormone) surge, and maintain the high levels of progesterone.

Question 44

Oestradiol sulphate + Valerate

Answer 44

A hydroxylated metabolite of oestradiol or oestrone

Oestrogen nuclear hormone receptor agonist

MoA: Oestradiol enters the female organs, breasts, hypothalamus, pituitary and interacts with the oestrogen receptor. The receptor then enters the nucleus, and regulate gene transcription. Oestrogens increase the hepatic synthesis of sex hormone binding globulin (SHBG), thyroid-binding globulin (TBG), and other serum proteins and suppress follicle-stimulating hormone (FSH) from the anterior pituitary.

Question 45

Mestranol

Answer 45

A synthetic derivative of oestradiol

Oestrogen nuclear hormone receptor agonist

MoA: Ethinyloestradiol is orally bio-active – it’s the oestrogen used in almost all combined oral contraceptive pills.

Question 46

Mefanamic acid

Answer 46

NSAID - analgesic, anti-inflammatory, and antipyretic
COX inhibitor

MoA: Mefanamic acid inhibits the COX-1 and COX-2 enzymes, reducing the production of prostaglandin synthesis, by prostaglandin synthase. This reduction in prostaglandin synthesis is the reason for the reduction in the symptoms of pain that are temporarily reduced.

Question 47

Tranexamic acid

Answer 47

Plasminogen inhibitor

Antifibrinolytic drug

MoA: Tranexamic acid competitively inhibits the activation of plasminogen to plasmin. Plasmin degrades fibrin clots, fibrinogen, and other plasma proteins, including the procoagulant factors V and VIII.

Use: In patients with hereditary angioedema, inhibition of the formation and activity of plasmin by tranexamic acid may prevent attacks of angioedema by decreasing plasmin-induced activation of the first complement protein (C1).