Pharmacology

Question 1

Metoclopramide mechanism of action?

Answer 1

Dopamine Antagonist

• Dopamine acts via the hypothalamus to cause inhibition of prolactin secretion and if this is interrupted, prolactin is excreted to excess.

Question 2

Carboprost

Answer 2

Prostaglandin F2 alpha

Caution is asthmatics because of risk of bronchospasm.

Question 3

Misoprostol

Answer 3

Prostaglandin E1

Question 4

Dinoprostone (Cervidil/Propess)

Answer 4

Prostaglandin E2

Question 5

Enzyme Inducing Anti Epileptic Drugs?

Answer 5

1. Carbamazepine
2. Phenytoin
3. Primidone
4. Topirimate

Increased risk of haemorrhagic disease of the newborn therefore babies should be offered 1mg IM vitamin K.

Question 6

Adalimumab:
1. Drug type and mode of action
2. Used to treat which conditions
3. Guidance in Pregnancy
4. Breastfeeding guidance

Answer 6

1. Biologic agent, anti TNF activity
   IgG1 antibody
2. RA, juvenile arthritis, psoriasis, psoriatic arthritis, ank spond, IBD, sarcoidosis
3. Actively transported across the placenta. By term, active transportation across the placental barrier ensures that drug levels in the neonate are often in excess of those in maternal circulation.

Moreover, it has a very long half life of 8-20 days which has lead to very high levels in the neonate (98-400% maternal drug levels).

To ensure that low levels of Anti-TNF or none at all - the latest BSR guidelines recommend that Adalimumab be discontinued in the 3rd trimester.

4. Safe in BF - recommence immediately PP

Question 7

Belimumab, Rituximab
1. Examples
2. Mode of action
3. Fetal considerations

Answer 7

1. B cell depleting Agents
   Also immunoglobulins that cross the placenta from the 2nd trimester onwards.
2. Transient cytopenias and neonatal B cell depletion that can persist for up to 6 months

Question 8

List live attenuated vaccines:

Answer 8

1. MMR
2. Rotavirus
3. Smallpox
4. Chickenpox
5. Yellow fever

Avoid in babies exposed to biologics in pregnancy for 6 months.

Question 9

Mastitis:
1. Organisms
2. Anti microbial
3. If Pen allergic

Answer 9

1. MSSA, Streptococci, MRSA
2. Flucloxacillin + Clindamycin
3. Vancomycin + Clindamycin
   Clindamycin/Teicolplanin are alternatives

(Trough level Vanc 5-20mg/l necessary)

Question 10

Caesarean section wound infection or IV cannula site infection:

1. Organisms
2. Anti microbial
3. If allergic

Answer 10

1. MRSA, MSSA
2. MRSA - Vanc + Clindamycin
   MSSA - Fluclox + Clindamycin
3. MRSA - Clindamycin /Teicoplanin
   MSSA - Vanc + Clindamycin

Question 11

Endometritis

1. Organisms
2. Antimicrobial
3. If allergic

Answer 11

1. Gram negative anaerobes, streptococci
2. Gentamicin (one dose immediately) + Cefotaxime + Metronidazole
3. Gent + Clindamycin + Cipro

Question 12

Acute Pyelo (postpartum):

1. Organisms
2. Antimicrobial
3. If allergic

Answer 12

1. Gram neg bacteria, occasionally staph and strep
2. Cefotaxime + Gentamicin
3. Cipro + agent

ESBL’s: Gent + Meropenem

Question 13

Toxic Shock Syndrome (post partum):

1. Organisms
2. Antimicrobial
3. If allergic

Answer 13

1. Staph / Strep
2. Fluclox + Clindamycin + Gent

For MRSA- use Vanc instead of fluclox.

3. Vanc + Clindamycin + Gent

Regimen MUST contain antitoxin agent such as Clindamycin or Linezolid.

Question 14

Lidocaine

Answer 14

Blocks fast voltage gated sodium channels

Antiarrhythmic

Half life 2 hours

Hepatic metabolism

Question 15

When to stop Infliximab?

Answer 15

Stop at 16/40

Question 16

When to stop Etanercept?

Answer 16

Stop prior to 3rd trimester

Question 17

When to stop Certolizumab?

Answer 17

Safe all trimesters and with BF

Question 18

When to start ART in HIV +ve pregnant patients?

Answer 18

Should be started at the start of the second trimester (13/40).

The aim is to suppress viral load to < 50 HIV RNA copies/mail plasma but the time of delivery.

Question 19

Nitrofurantoin and cautions postnatally?

Answer 19

CI for use directly in infants < 1 month old or in those with G6PD deficiency due to potential for haemolysis.

Question 20

Most pregnancy friendly anti-TNF drug safe throughout all trimesters?

Answer 20

Certolizumab

Not actively transported across the placenta like other biologics and doesn’t accumulate.

Question 21

Antimuscarinic Drugs used in OAB?

Answer 21

Oxybutinin - first line, immediate release
Solifenacin
Tolterodine
Darifenacin

Question 22

Mirabegron

Answer 22

Beta 3 adrenergic agonist
2nd line treatment for OAB

Question 23

Desmopressin (DDAVP)

1. Mode of action
2. Uses
3. Cautions
4. SE’s

Answer 23

1. Synthetic analogue of vasopressin
2. Can increase levels of both factor VIII and VWF 3-4 fold
3. Avoid in women with PET. Antiduretic properties mean fluid restrict to 1L/ 24 hours or check electrolytes.
4. Flushing, headache, hypotension

** clinicians should be aware that patients with type 2B VWD may develop thrombocytopaenia following DDAVP treatment **

Question 24

Side effects of TB drugs?

Answer 24

Rifampicin - discolouration of urine, sweat, saliva

Isoniazid - peripheral neuropathy

Pyrazinamide - arthralgia, gout, photosensitivity

Ethambutol - gout, neuritis

Question 25

Half life of thyroxine?

Answer 25

6-7 days Take on an empty stomach to maximise absorption.

Question 26

Drugs inhibiting absorption of Levothyroxine?

Answer 26

FeSO4 Calcium salts Cholestyramine

Question 27

Fetal risks with Lithium in Pregnancy?

Answer 27

1. Lithium increases the rate of fetal heart defects to 60/1000 from 8/1000 in the general population. 2. Lithium increases the risk of Ebstein’s anomaly from 1/20,000 to 10/20,000

Question 28

Fetal risks with Carbimazole?

Answer 28

1. Aplasia cutis congenita (absence of portion of skin, often localised to the head) 2. Craniofacial malformations (choanal atresia, facial dysmorphism) 3. Defects of abdominal wall and GIT (exomphalos, oesophageal atresia) 4. VSD

Question 29

PTU and Carbimazole SE’s?

Answer 29

1. Puritis 2. n+v 3. Diarrhoea 4. Agranulocytosis - discontinue therapy. If women on Carbimazole present with evidence of infection such as sore throat, perform FBC! 5. Fetal goitre - 10% 6. Transient neonatal hypothyroidism - 1-5% 7. Drug rash 5%

Question 30

Olanzapine increased risk Of what in Pregnancy?

Answer 30

Gestational Diabetes

Question 31

Clomiphene Citrate

Answer 31

1. Weak oestrogen, competes with endogenous oestrogens for receptors at the hypothalamus, blocking negative feedback of endogenous oestrogens. 2. GnRH levels rise and stimulate gonadotropin release resulting in ovarian stimulation and a rise in serum oestradial 3. Effective of ovulation induction in women with anovulatory fertility 4. 5-10% risk of multiple pregnancy, risk of OHSS 5. SE: visual disturbance, hot flushes, abdo discomfort, breast tenderness, weight gain, menorrhagia, dizziness, hair loss, depression

Question 32

Tamoxifen

Answer 32

Breasts: - antagonises oestrogen action on breast - 50% reduction in recurrence and 25% reduction in mortality (ER +ve breast ca) Reproductive Tract: - anti-oestrogenic effects in pre menopausal women - oestrogenic effects in post menopausal women with stimulation of the endometrium, myometrium and vagina. There is stimulation of fibroid growth, induction/ re activation of endometriosis and adenomyosis. Risk of EC for tamoxifen users 1.6/1000 vs 0.2/1000 placebo. Serum lipids: - reduction in serum cholesterol and LDL cholesterol in post menopausal women. - risk of VTE increased 4.7 - 5.7 fold.

Question 33

Clonidine 1. Mode of action 2. Use

Answer 33

1. Alpha 2 agonist 2. Can be used to treat Vasomotor symptoms in Menopause - oral ineffective, trans dermal effective

Question 34

Side effects of Atosiban?

Answer 34

Nausea, Vomiting Tachycardia Hypotension Headache Hyperglycaemia Hot flushes Injection site infection

Question 35

Side effects of Nifedipine?

Answer 35

Headache Flushing Tachycardia Palpitations Hypotension Dependent oedema Constipation Increased urinary frequency Eye pain Visual disturbance

Question 36

Tranexamic Acid 1. Mechanism of action

Answer 36

Prevents conversion of plasminogen to plasmin. This prevents fibrin degradation and preserves the framework of fibrin's matrix structure.

Question 37

Which TB drug is associated with hepatitis?

Answer 37

Isoniazod

Question 38

Peak concentration of Misoprostol: 1. Oral/Sublingual 2. Buccal/Vaginal

Answer 38

1. Oral/Sublingual - 30 minutes 2. Buccal/Vaginal - 70-80 minutes

Question 39

Warfarin: 1. MOA 2. Half life 3. When to stop pre op

Answer 39

1. Vit K epoxide reductase inhibitor 2. Half life: 36 hours 3. Stop 5/7 pre op. Check INR the day before surgery, if > 1.5 may need Vit K. Consider bridging with LWMH if high risk VTE.

Question 40

Apixaban + Rivaroxaban 1. MOA 2. Half life 3. When to stop pre op

Answer 40

1. Factor Xa inhibitor 2. Apix: 8 hours, rivarox: 9hrs 3. Low bleeding risk, stop: a) Creat clearance > 30 - stop 24 hrs b) Creat clearance < 30 - stop 48 hrs High bleeding risk, stop: Creat clearance > 30 - stop 48 hrs Creat clearance < 30 - stop 72 hours

Question 41

Lithium: 1. Risk of cardiac malformation? 2. Timing of fetal ECHO? 3. When to check lithium levels? 4. Anaesthetic consideration? 5. BF advice 6. Maternal considerations

Answer 41

1. 2% (BG risk 0.6-1.2%) 2. 18-22 weeks consider fetal echo 3. Lithium levels every 4 weeks until 36/40 then weekly thereafter. 4. Can interact with neuromuscular blocking agents - anaesthetic assessment 3rd trimester 5. BF not recommended due to neonatal toxicity 6. Risk of maternal diabetes Insipidus

Question 42

Lithium level: 1. Sub therapeutic 2. Level that lithium toxicity develops 3. Fatal cardio toxicity and neurotoxicity

Answer 42

1. < 0.6 2. > 1.2 3. > 2