Pharmacology

Question 1

carbimazole

Answer 1

• Is a thioamine
• inhibits thyroid peroxidase (enzyme converts I- to iodine)
• Commonly used in Graves’

Question 2

propulthiouracil

Answer 2

• is a thioamine
• inhibits thyroid peroxidase & inhibits conversion of T4–> T3
• More likely to cause hepatotoxicity

Question 3

What is treatment for hypothyroidism?

Answer 3

Thyroid replacement

Question 4

Liothyronine

Answer 4

• T3
• More active than T4
• Less strongly protein bound to TBG than T4–> so shorter 1/2 life
• levels are less stable during the day

Question 5

Thyroxine (T4)

Answer 5

• Acts mostly after conversion to T3
• most is protein bound in plasma (TBG)
• slow accumulation and onset of action–> may lead to initially poor compliance

Question 6

Mechanism of action for Benzos

Answer 6

• Bind to allosteric site on GABA A
• Increased affinity for GABA
• Causes increased frequency of Cl- channel opening
• DOES NOT CHANGE MEAN OPEN TIME
• Get a ceiling effect
• Increase POTENCY of GABA
• considered safe in OD

Question 7

Mechanism of action of barbituates

Answer 7

• Increase mean open time of Cl- channel
• So increase the SENSITIVITY and MAXIMUM RESPONSE of Cl- channel–> INCREASED Cl- influx
• increase the EFFICACY of GABA

Question 8

Delta-9 Tetrahydrocannabinol

Answer 8

• Main ingredient in cannabis
• Sharpen sensory awareness
• Acts on cannabinoid receptors:
• G protein coupled
• inhibit adenylate cyclase (required for transmission, so you inhibit transmission)
• 2 receptor subtypes
  1) Central (CB1)
• impaired short term memory
• impaired motor coordination
• analgesia
  2) Peripheral (CB2)
• tachycardia
• bronchodilation

Question 9

What are the 1st gen anti-depressants?

Answer 9

• Tri- cyclic anti- depressants

- MAO inhibitors

Question 10

Tri- cyclic anti- depressants

Answer 10

• Block NA and 5HT reuptake
• Very non-selective (poor selectivity)
• Also block:
  1) a-adrenoceptors
  2) MuscR
  3) Histamine receptors
  4) 5HT receptors
• Clinical effect can take weeks to develop

Question 11

MAO inhibitors

Answer 11

• Increase levels of 5HT, DA and NA
• Tends to show selectivity for 5HT and NA over DA
  a) Irreversible–> get cheese reaction
  b) Reversible–> MAO A specific- less cheese reaction

Question 12

SSRIs

Answer 12

• Selective for 5HT uptake

- SSNRI–> venlaflaxine: minimal DA effects

Question 13

Somatostatin analogues

Answer 13

• Used in treatment for acromegaly
• GHIH analogues octreotide and lanreotide–> have longer 1/2 life than GHIH
• not orally bioactive–> must be injected

Question 14

Pegvisomant

Answer 14

GH antagonist, used in treatment for acromegaly

Question 15

Long acting insulin

Answer 15

• Glargine insulin (Lantus)
• Determir insulin (Levemir)

these are GM insulin

Question 16

Short acting insulin

Answer 16

Humalog

Question 17

HbA1C

Answer 17

• Hb that is NON- ENZYMATICALLY glycosylated by hyperglycaemia
• Irreversible, so lasts for 3 months (lifespan of RBC)

Question 18

Fructosamine

Answer 18

Pts who have a high RBC turnover will have an artifically low HbA1C due to high no. of young RBCs (reticulocytes)
- so this can be another measure of how good BG control is