pharmacology (non-hormonal) Flashcards
which % of pregnancies is affected by:
i. HTN
ii. PET
i. 10%
ii. 3%
clear indications for rx of raised BP in pregnancy (4):
persistant BP >160/110
acute severe HTN
fulminating PET
eclampsia
BP above which we medicate
150/100
beta blockers SE:
IUGR
neonatal hypoglycaemia and bradycardia (rare)
which BB is sometimes CI as their effect in early and late pregnancy is not known?
atenolol
methyldopa
(2nd line)
mechanism of action:
centrally acting
is metabolised to α-methylnoradrenaline (it’s active component)
It works as a post-synaptic α2 agonist reducing central sympathetic outflow
methyldopa SE
- rebound HTN
- depressed mood with LT use
- Flattened CTG variability
- Autoimmune haemolytic anaemia (rare)
- Raised prolactin (outside of pregnancy)
- Hepatitis
nifedipine
(not licensed in pregnancy but commonly used 2nd line)
- use MR as acutely can cause hypotension
effects of nifedipine:
- member of the dihydropyridine group and
blocks inward flux of calcium through voltage
gated calcium channels - has a preferential effect on vessels as a vasodilator rather than the myocardium
- known effect on the myometrium – it
may inhibit premature labour (unlicensed use) and
has been used as a tocolytic agent
nifedipine SE:
- Acute hypotension if given sub-lingually
- Peripheral oedema
- Headache + flushing
hydralazine
(iv used for acute HTN)
how is it metabolised and by which organ?
by acetyaltion in liver
hydralazine SE:
- acute hypotension if given too fast or often (give over 5 mins at least, up to every 15 mins max)
- lupus-like syndrome (v rarely - in pts who acetlyate slowly)
magnesium sulphate:
(has rapid onset of action- maintained for 24 hrs post delivery/ fit)
i. how does it work?
ii. in which instances would you require monitoring?
i. membrane stabiliser
ii. if oliguric
magnesium sulphate SE:
- hyporeflexia (presents in advance of more serious SE)
- resp depression
- cardio-respiratory arrest
antihypertensives to avoid in pregnancy:
- ACEi
- thiazide diuretics
ACEi associations:
- Congenital malformations – especially CVS
- Skull defects
- Oligohydramnios + impaired fetal renal function
effect on neonate with bendroflumethiazde:
neonatal thrombocytopaenia
indications for tocolysis:
- To achieve 24 hour steroid latency < 34 weeks
- to allow for in-utero transfer
drugs used for tocoloysis:
- nifedipine
- atosiban
less commonly:
- beta-sympathomimetics (salbutamol, ritodrine,
terbutaline) NICE recommends avoid - magnesium sulphate - recommended for neuroprotection from 24–30 weeks gestation and possibly 30–34 weeks
- GTN patches - no better than ritodrine but less SE
beta-sympathomimetics (salbutamol, ritodrine,
terbutaline)
SE
tachycardia
hypotension
pulmonary oedema
hypokalaemia
hyperglycaemia
i. which medication is given prior to ECV (external cephalic version) to improve success rates?
ii. in only which group of women is this done?
iii. SE of this medication
i. terbutaline s/c
ii. primagravida
iii. transient maternal tachycardia and tremor
which medication is given as emergency tocolysis in response to hyperstimulation (usually from oxytocin)
terbutaline iv
which medication should be given to reduce PET risk in high risk pts?
from/to which gestation?
why it stopped in late pregnancy?
aspirin 75mg
12 to 36 weeks gestation
theoretical risk of neonatal haemorrhage
high risk RF for PET
- hypertensive disease during a previous pregnancy
- CKD
- autoimmune disease such as SLE or antiphospholipid
syndrome - type 1 or type 2 diabetes
- chronic hypertension.
risks associated with NSAIDs in pregnancy:
- A possible increase in miscarriage [5]
- Fetal renal impairment and oligohydramnios
- Increased risks of premature closure of the ductus
arteriosus – the evidence for this is actually poor - Potential small increased risk in necrotising
enterocolitis (NEC) - They can also cause maternal upper GI symptoms
and renal impairment over prolonged periods
on which receptor do opioids work?
what is the effect of this?
μ opioid receptors
reduces cerebral appreciation of pain
opioids SE
- Sedation
- Nausea and vomiting
- Constipation
- In large quantities (invariably as drugs of abuse) they
may cause a neonatal withdrawal syndrome
pain relief in labour
ENTONOX – 50/50 nitrous oxide / O2 mix. This is
safe, stable and has a very rapid onset and offset. It is
widely used and highly effective for many.
6 Side effects: nausea, “feeling drunk”
6 Pethidine IM is widely used despite little evidence of
effective pain relief.It has a rapid onset and short halflife.
6 Side effects: nausea and vomiting, narcosis,
respiratory depression in the neonate if within
2 hours of delivery.
6 Morphine though less widely used appears to be more
effective and as safe. Both pethidine and morphine
are μ–opioid receptor agonists.
6 Combinations of bupivicaine (local anaesthetic) and
fentanyl (opiate) in epidural administration provide
highly effective pain relief.
6 Side effects: hypotension, loss of mobility, higher
chance of assisted delivery and rarely complications
associated with insertion (dural tap, haematoma, high
blockade).
drugs used to manage 3rd stage of labour:
- syntometrine (ergometrine 500mcg/ syntocin 5IU)
- syntocin (synthetic oxytocin)
- misoprosotol
- carboprost
syntometrine
i. SE
ii. CI
causes prolonged vasoconstriction
i. N+V, HTN
ii. hypertensive disorders
syntocin
synthetic oxytocin
causes short-term uterine contraction
misoprostol
i. class
ii. SE
i. PGE1 analogue
ii. diarrhoea/ N&V
carboprost
i. class
ii. caution in
iii. avoid in
i. PGF2α analogue
ii. HTN
iii. asthmatics
hyperemesis gravidarum
i. incidence
i. 1-2% of all pregnancies
anti-emetics:
1st line
1st line:
- Promethazine
2nd line:
- metoclopramide
- prochloperazine
3rd line
- ondansetreon
4th line
- corticosteroids (methylprednisolone or hydrocortisone)
promethazine
i. which family of drugs does it belong to?
ii. how does it work? (2)
iii. SE
i. phenothiazine family
ii. histamine antagonist (H1), also some anti-muscarinic effect)
iii. sedation
extrapyrimidal neurological effects such as tardive
dyskinesia (rarely)
(prochloperazine is also in this family and has similar SE)
metoclopramide
i. class
ii. how does it work?
ii. SE
i. dopamine (D2) antagonist and a 5-HT3 antagonist
ii. central anti-emetic effect and increases gastric emptying,
iii. akathisia (restlessness), tardive dyskinesia
ondansetron
(3rd line, not licensed in pregnancy)
i. class
ii. SE
i. 5-HT3 antagonists
ii. headache, diarrhoes, sedation
2 drugs used for menorrhagia (non-hormonal)
- mefenamic acid
- tranexamic acid
mefenamic acid
i. class
ii. how much do they reduce blood loss
i. NSAID, prostaglandin inhibitor
ii. 30%
SE = same as for other NSAIDs
tranexamic acid
i. class of drug
ii. how does it work
iii. % by which it reduces blood loss
iv. SE
v. caution in which group of pts?
i. anti-fibrinolytic
ii. blocks conversion of plasminogen to plasmin and reduces fibrinolysis
iii. 40-50%
iv. mild GI upset
v. pts with cardiac disease
urge incontinence
i. type of drug used commonly
ii. examples x2
iii. main receptor
iv. % of pts which see improvement in sx
i. anti-muscarinics
ii. tolteridone, oxybutynin
iii. M3 (oxybutanin is less selective than tolteridone)
iv. 60-70%
anti-muscarinic SE
dry mouth
dry eyes
constipation
dizziness
MR preparations may reduce SE
other medications used for urge incontinence:
(than tolteridone and oxybutynin)
imipramine (also anti-muscarinic)
Trospium chloride
propiverine
desmopressin
drug used for stress incontinence:
i. what class is this?
ii. how does it work?
iii. % of pts it improves sx in
iv. SE
v. % of pts who experience SE
duloxetine
i. SNRI
ii. increases urinary sphincter tone
iii. 50%
iv. dissiness, nausea, insomnia
v. 10-20%
classes of cytotoxic agents & how they work:
Antimetabolites - interfere with DNA and RNA
synthesis e.g. 5-FU, methotrexate (folate antagonist)
Alkylating agents - form covalent bonds with DNA
bases e.g. cyclophosphamide, isofosfamide
Intercalating agents - bind to DNA, thus inhibiting
its replication e.g. cisplatin, carboplatin
Anti-tumour antibiotics - complex mechanisms
leading to inhibition of DNA synthesis e.g.
bleomycin, doxorubicin, etoposide
Drugs directed against spindle microtubules
inhibiting mitosis e.g. paclitaxel, vincristine
common regime in ovarian ca
platinum based regimes
Carboplatin +/- paclitaxel
endometrial cancer
chemotherapy usually only in recurrent or metastatic disease
most commin regimes:
carboplatin +/- paclitaxel or
doxorubicin and cisplatin
cervical cancer
cisplatin & radiotherapy reduce risk of relapse for those undergoing radiotherpay after surgery
cisplatin & methotrexate - for metastatic disease (response rate may be low)
vulval ca
5-FluUracil (5-FU) +/- cisplatin
+ radiotherapy
used if unfit for surgery or as sole therapy for sx control in metastatic disease
trophoblastic disease
Methotrexate for simple
trophoblastic disease. EMA-CO (Etoposide,
Methotrexate, Dactimomycin, Cyclophosphamide,
Vincristine) for high risk trophoblastic disease. Both
have cure rates of around 99%
SE of chemotherapy:
Haematological - bone marrow suppression which
eventually recovers; cellular nadir is around 7-14 days
resulting in neutropenia, anaemia and
thrombocytopenia.
- GI - side effects are due to loss of
epithelial cells:
- Nausea and vomiting are very common with most
agents and are actively prevented with anti-emetics.
- Mucositis: (esp. methotrexate) resulting in ulcers
in mucous membranes especially oral – these
usually resolve spontaneously.
! Diarrhoea is less common and usually transient.
- Alopecia - Taxanes (e.g. paclitaxel), doxorubicin and
etoposide commonly cause temporary hair loss. This
is seen less commonly with carboplatin and cisplatin.
- Neurological – usually dose-related and improve on
dose reduction or stopping:
- Peripheral neuropathy is commonly seen with
paclitaxel and cisplatin
- Tinnitus is associated with cisplatin
- Constitutional - tend to have cumulative effects but
resolve on cessation.
- Lethargy
- Anorexia
