Pharmacology non-hormonal therapy in obstetrics Flashcards
How does labetolol work?
non-specficic alpha and beta blockade
possible side effects of long term labetolol use?
IUGR
Neonatal hypogylaecaemia + bradycardia
How does methyl dopa work?
Centrally acting and is metabolised to a-methylnoradrenaline
works on post synaptic a2 agonist reducing central sympathetic flow
Side effects of methyl dopa
rebound HTN depressed modd Flatterened CTG Autoimmune haemolytic anaemia (rare) raised prolactin hepatitis
how does nifedipine work?
dihydropyridine group and blocks inward flux of calcium though voltage gated calcium channels.
Works on vessels as vasodilator over myocardium
Does also effect myometrium
Not licensed in pregnancy
Side effects of nifedipine
acute hypotension if given SL - MR dosing given in pregnancy
peripheral oedema
headache + flushing
When is IV hydrazine used
acute hypertension
given slowly over a minimum of 5 minutes, can be repeated every 15 mins
patent vasodilator unknown mechanism
What is MgSo4 role in the treatment of PET?
Magpie trial - prevents seizures and reduced mat death
How does MgSo4 work? When do you need to monitor levels?
Membrane stabiliser
Monitor if oliguric
Side effects of MgSo4>
Hyporeflexia
Resp depression
Cardio-resp arrest
Side effects of ACEi in pregnancy
Congenital malformations
Skull defects
Oligohydramnios + impaired fetal renal function
- CI use in pregnancy
Effects of thiazide diuretics
neonatal thrombocytopenia
harmful for mother & baby
When are tocolytic agents used?
Unwanted uterine activity
- preterm labour
- acute hyper stimulation
- ECV
In which situations should tocolytic agents be used in preterm labour?
Under 34/40 to achieve 24 hours for steroids
in-utero transfer for neonatal care
Which drugs are used for tocolysis?
NICE guideline
- Nifedipine (unliscenced use)
- Atosiban (oxytocin antagonist) (nausea tachycardia, hypotension)
- beta-sympathomimetics (salbutamol/terbutaline), most commonly used
- MgSO4 - common in USA
- GTN patch
What are the side effects of beta-sympathomimetics (salbutamol/terbutaline)
Tachycardia Hypotension pulmonary oedema hypokalaemia hypergylcaemia - current NICE say avoid using them
What medication is used for neuroprotection from 24-30 weeks + possibly 30-34 weeks?
MgSO4
Which mothers should receive terbutaline prior to ECV?
Primips
SE: transient mat tachy and tremor
What drugs is used in hyper stimulation & what is the benefit?
Terbutaline IV
improve fetal heart rate patterns and fetal pH
What does of aspirin is given for prevention PET/IUGR and what gestation?
75mg OD
12-36 weeks
Which women are at high risk of PET and should recieve aspirin?
Hypertension disease in previous pregnancy
CKD
autoimmune conditions such as SLE or antiphospholipid syndrome
Type 1 or 2 diabetes
chronic HTN
Why is aspirin stopped 2-3 weeks before delivery?
Theoretical risk of neonatal haemorrhage due to anti-platelet effects
What are the SE of other NSAIDs such as ibuprofen?
- possible increased risk miscarriage
- fetal renal impairment and oligohydraminios
- increased risk premature closure of ductus arteriosus
- small increased risk NEC (necrotising enterocolitis)
- maternal upper GI symptoms and renal impairment
How do opioids work?
Activate u opioid receptors reducing cerebral appreciation of pain
Side effects of opioids?
Sedation
Constipation
N+V
in large quantities - neonatal withdrawal syndrome
What is ENTONOX
50/50 notorious oxide/oxygen mix. Stage and stable rapid onset
SE nausea and feeling drunk
Pethidine IM use and side effects
Widely used but little evidence of effective pain relief
Rapid onset + short half life
SE:
N+V
narcosis
resp depression of neonate if used 2 hour of delivary
Morphine less widely used seems safer and more effective
What drugs are used in an epidural?
Bupivicane (local anaesthetic) and fentynl (opioid)
SE of epidrual
Hypotension Loss of mobility higher chance of assisted delivery Dural tap haematoma high blockade
How much does active management of 3rd stage prevent PPH
50%
What is in syntometrine?
Ergometrine 500mg
Syntocinon 5IU
Side effects of syntometrine
Ergo - causes prolonged vasoconstriction
SE N+V
CI HTN pregnancies
Syntocinon - synthetic oxytocin and short term uterine contraction.
What other drugs can you used for management PPH
- Ergometrine alone
- Synto can be used as 40IU in saline individually
- Misoprostol 800mcg orally/vaginaly/rectally
- Carboporst
How does misoprostol work & SE
PGE1 analogue
Diarrhoea
N+V
How does carboprost work
PGF2a analogue
Caution in HTN CI in asthmatics
How does promethazine work? Side effects?
Histamine H1-receptor antagonist
Sedation and rare extra-pyramidal neurological SE such as tardtive dyskinesia
1st line
How does metoclopramide work? Side effects?
Dopamine D2 receptor antagonist
5-HT3 receptor antagonist
Akathisia (restlessness)
tardive kinésie
How doe prochlorperazine work? SE?
Dopamine D2 receptor antagonist
Sedation and rare extra-pyramidal neurological SE such as tardtive dyskinesia
How does ondansetron work? When should it be used?
Serotonin 5-HT3 receptor antagonist
Not liscensed in pregnancy - only use as 3rd line
What is 4th line treatment for hyperemesis?
Corticosteroid - some evidence but not large trials, not shown to be teratogenic
Why is heartburn common in pregnancy?
Reduced lower oesophageal sphincter tone induced by progesterone
What is in gaviscon
sodium alginate
calcium carbonate
sodium bicarb
What type of drugs is mefanamic acid?
By what % does it reduce menstrual blood loss?
Prostalgandin production inhibitor
30%
What type of drugs is tranexamic acid?
By what % does it reduce menstrual blood loss?
Anti-fibrionyltic
Blocks conversation of plasminogen to plasmin reducing fibrinolysis
40-50%
SE: GI upset and cuation with pre-existing heart disease
What types of drugs are tolteridone and oxybutynin?
Muscarinic antagonist (particularly M3 receptor) 60-70% effective at reducing incontinence and irritative symptoms SE: dry mouth, dry eyes, constipation, dizziness
What type of drugs is duloxetine?
When is it used?
What are its side effects?
Balanced serotonin and noradrenaline reptant inhibitor (SNRI)
For stress urinary incontinence, reduces stress incontience by 50%
SE: nausea, dizzy, insomnia occurs in 10-20%
what is the response rate to ovarian cancer?
What % relapse?
70%
50%
Does chemotherapy have a rolle in treating endometrial cancer?
Limited
reserved for recurrent or metastatic
