Pharmacology

Question 1

How do the following antibiotics work:

Macrolides
Penicillin
Metronidazole
Cephalosporins
Quinolones
Tetracyclines
Nitrofurantoin
Trimethoprim

Answer 1

Macrolides - peptidyltransferase inhibitor, to dow ith protein synthesis

Penicillin - betalactamase inhibitor which disrupts cell wall

Metronidazole - inhibits nucleic acid synthesis by generating radicals

Cephalosporins - betalactamase inhibitor which disrupts cell wall

Quinolones - DNA gyrase inhibitor

Tetracyclines - binds to the 30S subunit of ribosomes which prevents stuff attaching

Nitrofurantoin - damages DNA by generating reactive intermediaries

Trimethoprim - dihydrofolate reductase inhibitor

Question 2

What type of antibiotic is erythromycin

Answer 2

Macrolide

Question 3

What type of drug is ciprofloxacin

Answer 3

Quinolone

Question 4

What type of drug is doxycycline

Answer 4

tetracycline

Question 5

What are the features of fetal warfarin syndrome?

What are people treated with during pregnancy?

Answer 5

V-PLANTS

Ventriculomegaly
Pectus carinatum
Laryngomalacia
Agenesis of corpus callosum
Nasal bridge hypoplasia
Telybrachydactyly
Short stature

Causess FWS in 5% of fetuses exposed during week 6-12 pregnancy.

Converted to LMWH during pregnancy - an exception can be mechanical heart valve

Question 6

What is the teratogenic effect of metronidazole

Answer 6

lactose intolerance

Question 7

What is the teratogenic effect of ACE-i/ARBs

Answer 7

KIDNEY STUFF (and lung)

Renal dysgenesis
Oligohydramnios (not producing any wee)
Renal failure

IUGR
Pulmonary atresia

Question 8

What is the teratogenic effect of tetracyclines

Answer 8

MOUTH

Yellow teeth
Cleft palate

Question 9

What is the teratogenic effect of Carbimazole

Answer 9

GUT AND SKIN

Omphalocele
Choanal altresia
Aplasia cutis - no skin

Question 10

What is the teratogenic effect of sodium valproate AND lithium

Answer 10

cardiac effects

Question 11

What is the teratogenic effect of gentamicin

Answer 11

ototoxicity

Question 12

What are the doses for prophylactic for LMWH: enoxaparin, dalteparin

Answer 12

Enoxaparin
50-90 40mg
90-130 mg 60mg
130-170mg 80mg
170mg 0.6mg/kg

Dalteparin
50-90 5000IU
90-130 mg 7500IU
130-170mg 10,000IU
170mg 75 u/kg

Question 13

Which morphine receptors do the following act on:

Strong opioids

Co-codamol

Answer 13

THEY ARE AGONISTS

Strong ones: morphine/fentanyl/methadone: MU receptors

Mu but also kappa and delta

Question 14

LIDOCAINE

How does it work?
What is the half life?
What is the maximum dose with and without adrenaline?

Answer 14

It blocks fast voltage gated sodium channels
Half life is 2 hours, metabolised by the liver
Maximum dose without adrenaline is 3mg/kg
Maximum dose with adrenaline is 7mg/kg

Question 15

How do all the antiemetics work?

Answer 15

They INHIBIT STUFF

REMEMBER H1 and D2

Promethazine and cyclizine - Histamine H1 antagonist

Ondansetron - serotonin antagonist

Prochlorperazine and metoclopramide - Dopamine D2 antagonist

Question 16

How does ranitidine work?

Answer 16

Blocks H2 receptors

Question 17

What are the receptors on the gastric parietal cells

Which is the most significant receptor?

Answer 17

H2 receptors
Gastrin receptors
Acetylcholine receptors

Most significant = H2

Question 18

What are the options for antenatal steroids

Answer 18

2x betamethasone 12mg 12-24h apart

4x dexamethsone IM 6mg

Question 19

What are the side effects of the following cardiac medications:

ACE-i
Loop diuretics
CCBs
BBs

Answer 19

ACE-i:
- Dry cough
- Sometimes renal impairment but rare

Loop diuretics
- Low Salts - Na/Mg/Ca/Mg
- Postural hypotension

CCBs
- Peripheral swelling

BBs
- Bronchosmasp
- Abnormal glycaemic control
- Cold fingers and toes

Question 20

Which of the antiemetics can you not give to <20 year olds and why

Answer 20

Metoclopramide

Can lead to oligogyric crisis

Question 21

How do you reverse morphine OD

Answer 21

Naloxone

Question 22

How do you reverse benzo OD

Answer 22

Flumazenil

Question 23

How do you reverse warfarin OD

Answer 23

Vitamin K/octiplex

Question 24

How do you reverse heparin OD

Answer 24

Protamine

Question 25

How do you reverse paracetamol OD

Answer 25

Parvolex N-acetylcysteine

Question 26

How does clomiphene induce ovulation

Answer 26

Blocks the oestrogen receptors in the hypothalamus to block the negative feedback loop. This means GnRH is still produced --> LH and FSH from AP --> ovulation

Question 27

What are the benefits of antenatal corticosteroids for the mum

Answer 27

NONE

Question 28

When are antenatal steroids given?

Answer 28

For risk of PTB vaginally up to 34+6 For PCB up to 38+6

Question 29

Which of the antifungals works by inhibiting squalene epoxidase

Answer 29

Terbinafine! Im no_t been fine_ I'm squealing!!!

Question 30

With Warfarin, what are the target INRs for the following: PE AF Mitral valve replacement

Answer 30

PE and AF 2-3 Mechanical valve 2.5-3.5 Mechanical valve 3.0-4.0 if has PE despite Warfarin

Question 31

What is the first line therapy for N&V in early pregnancy

Answer 31

Cyclizine or promethazine or prochlorperazine

Question 32

What is the mechanism of action of tamoxifen What cancers does it help? Or increase the risk of? What does it do to bone density? What about gynaecomastia? What about lactation? Who cant have it?

Answer 32

Oestrogen antagonist in breast tissue Partial agonist in endometrial tissue - therefore increases risk of endometrial Ca It improves bone density It is a treatment for gynaecomastia It inhibits lactation CANT HAVE IT: - Personal or family history of VTE

Question 33

Give some examples of SERMs How do they work

Answer 33

Clomiphene - blocks oestrogen receptors in hypothalamus to block negative feedback Tamoxifen - blocks oestrogen receptors in breast tissue but agonist in endometrial tissue

Question 34

How much more potent is fentanyl in comparison to morphine

Answer 34

100x more potent!

Question 35

When do you restart warfarin following birth

Answer 35

SAFE in breastfeeding. Restart 5-7 dys after birth

Question 36

How do Imodazole antifungals work? What are examples?

Answer 36

They bind to the phosphlipids in the cell wall which elads to lack of ergosterol