1. Antihypertensive drugs in
pregnancy
Aditi laad

2. • Hypertensive disorders complicated 5-10% of all
pregnancies

3. Classification
Usually 4 types
1. Gestational hypertension
2. Preeclampsia and eclampsia syndrome
3. Chronic hypertension
4. Preeclampsia superimposed on chronic
hypertension

4. Gestational hypertension
• Characterized most often by new onset elevation
of bp 140/90mmHg or greater after 20 weeks of
pregnancy but in whom proteinuria is not
identified.
• Gestational hypertension is reclassified by some
as transient hypertension if evidence of
preeclampsia does not develop and bp returns
to normal by 12 weeks
• 6-15% in nulliparous and 2-4% in multiparous

5. Preeclampsia

6. Preeclampsia with severe features

7. Eclampsia
• Presence of new onset grand mal seizures in
woman with preeclampsia that cannot be
attributed to some other cause.
• It can be antepartum, intrapartum or
postpartum .

8. Chronic hypertension
• High blood pressure before conception or before
20 weeks of pregnancy
• Should be documented on two ocassions at least
4 hour apart
• Blood pressure that persists even after 12 weeks
postpartum is also considered chronic
hypertension

9. Preeclampsia superimposed on chronic
hypertension
• When one or more features of preeclampsia
develop for the first time after 20 weeks in a
woman with preexisting chronic hypertension.

10. Management
• Pregnancy complicated by gestational
hypertension is managed based on severity
,gestational age, and presence of eclampsia.

11. Management in gestational
hypertension or preeclampsia without
severe features

12. DETAILED EXAMINATION AT EVERY VISIT , ASK ABOUT SEVERE
FEATURES LIKE HEADAHE, VISUAL DISTURBANCES, EPIGASTRIC
PAIN ,SHORTNESS OF BREATH AND RAPID WEIGHT GAIN
• CBC[PLATELETS], SR CREATININE, LFT, URINE PROTEI N 24HOUR
• Analysis for proteinuria or urine protein:creatinie ratio on
admittance and at every 2 days thereafter
• Women with gestational hypertension are to be evaluated for proteinuria at every
visit, but if diagnosis of preeclampsia is made additional evaluation of
proteinuria not necessary
• Instructed regular diet with no salt restriction
• FOR WOMEN WHO HAVE NOT GIVEN BIRTH, MANAGEMENT CAN BE
DONE AT HOSPITAL OR HOME, WITH RESTRICTED ACTIVITY AND
SERIAL FOETAL AND MATERNAL EVALUATION

13. • FOETAL EVALUATION :
1. DAILY KICK CHARTING/DFMC
2.GROWTH SCAN FOR FOETAL GROWTH
EVERY 3 WEEKS
3.AFI ASSESSMENT EVERY WEEK
4.NST ONCE WEEKLY IN GESTATIONAL
HYPERTENSION AND TWICE WEEKLY IN
PREECLAMPSIA WITHOUT SEVERE
FEATURES

15. • ANTIHYPERTENSIVE THERAPY
• The national institute of health and clinical
excellence guidelines recommends treatment at
bp levels 150mmHg systolic or 100mmHg
diastolic or both and to keep bp b/w <150
systolic and 80-100 diastolic.
• According to acog, task force recommendation
antihypertensives not to be administer if bp
<160/110 mmHg.

16. Time of delivery
• For women with mild gestational hypertension
and preeclampia without severe features delivery
at 37 weeks suggested
• 34weeks or more if any of following is present:
1. Progressive labor or rupture of membranes
2. Usg shows foetal weight <5th percentile
3. Oligohydramnios[persistent afi <5cm]
4. Persistent BPP 6/10 OR LESS

17. MgSO4
• MgSO4 prophylaxis not recommended unless
signs and symptoms[headache,altered mental
state, blurred vision,scotomas,clonus, and rt
upper quadrant abdominal pain] are there which
lead to eclampsia

18. Severe preeclampsia
• Results in both acute and chronic complication in
both women and newborn
• Maternal complications-pulmonary edema, MI ,
Infarction, stroke, ARDS , coagulopathy, severe
renal failure, HELLP syndrome , recurrent severe
hypertension, abruptio placentae, subcapsular
liver hematoma and retinopathy.
• For women with severe preeclampsia at or beyond
34weeks of gestation and in those with unstable
maternal fetal conditions irrespective of gestation,
delivery is recommend

20. Expectant management
• MATERNAL ASSESMENT
• Vitals signs ,fluid intake[STRICT I/O
CHARTING] and urine outpuT every 8 hourly
• Symptoms of severe preeclampsia should be
monitored 8 hourly
• Presence of contractions,bleeding, abdominal
pain, rupture of membranes monitored 8 hourly
• Lab tests[CBC, PLATELET COUNT, LIVER
ENZYME, SR CREATININE PERFORMED
DAILY, IF TESTS NORMAL CAN BE DONE
ALTERNATE DAYS]

21. • FOETAL ASSESSMENT
1. Strict DFMC/kick counts
2. Nst with uterine contraction monitored daily
3. BPP twice weekly
4. Serial foetal growth testing every 2 weeks and
umblical artery doppler every 2 weeks if iugr
suspected.

22. INDICTATION OF DELIVERY DURING
EXPECTANT MANAGEMENT
• MATERNAL INDICATION
1. Recurrent severe hypertension
2. Recurrent symptoms of severe preeclampsia
3. Progressive renal insufficiency [sr creatinine >1.1
mg/dl or doubling of creatinine levels
4. Persistent thrmbocytopenia or HELLP
5. PULMONARY EDEMA
6. Eclampsia
7. Suspected abruptio placentae
8. Progressive labor or rupture of membranes

23. • FOETAL INDICATION
1. Gestation age 34weeks or more
2. Severe foetal growth restrictions[<5th
percentile]
3. Persistent oligohydrmnios[maximum vertical
pocket <2cm]
4. BPP 4/10 or less on at least two occasions 6
hour apart
5. Reversed end diastolic flow on um artery
doppler
6. Foetal death
7. Recurrent variable or late decelertions
during NST

26. HELLP
1. Haemolysis (microangiopathic H.A.)
Burr cells, schistocytes on PBS, bilirubin >
1.2mg/dl, absent plasma haptoglobin
2. Elevated liver enzyme-- AST > 72 IU/L,
LDH > 600 IU/L
3. Low platelets-- < 1 lakh/mm3

27.  Mississipi classification
 CLASS 1 :severe thrombocytopenia (PC<50000)
 Class 2:moderate thrombocytopenia(btw 50,000
and 1 lac)
 Class 3:MILD thrombocytopenia(btw 1 lac and
150000)
 MORBIDITIES ASSOCIATED:
-abruptio placenta
-DIC
-pulmonary edema
-ARF
-ARDS
-death

28. MANAGEMENT
• Immediate hospitalisation
• Stabilise mother
▫ antihypertensives
▫ anti seizure prophylaxis
▫ correct coagulation abnormalities
• Assess fetal condition- FHR, doppler ultrasound,
biophysical profile
• Vaginal delivery:ripe cx,gest age >32 week,FHR
reactive,,no ind of cs sec,
• Better to perform CS if vaginal delivery not seen
within 12 hrs of IOL.

29. • For women HELLP and before gestation age of
foetal viability , it is recommended that delivery
undertaken shortly after maternal stabilization
• Recommended gestation age for delivery 34
weeks
• With women from gestation age of foetal viability
to 33+6week of gestation, delivery can be delayed
for 24-48hrs if maternal and foetal condition
remain stable to complete steroid dose
• Evidence in randomized trials of improvement of
platelets with steroid treatment, although no
evidence of benefit to improve maternal and
foetal outcome was found.

30. Eclampsia management
 Place pt in lateral decubitus.
 Mouth gag
 Suction oral secretions
 O2 by mask 8-10 l/min
 Elevate bedside rails to avoid injury
 Switch off lights, keep quite environment
surrounding pt.
 Pulse oxymeter, foley’s catheter, iv access
 MgSO4
 Start IV fluids at low rate 75 ml/hr.
 Antihypertensive : 1st drug of choice in severe HTN
is iv Labetalol.
 Deliver the pt.

31. • Continue MgSO4 till 24hrs postpartum to avoid
convusion.
• Phenytoin :
loading dose 10-15 mg/kg slow iv f/b maint dose
100mg iv every 6-8hrly.
For prophylaxis 100mg iv/im 4hrly.
• Oral phenytoin should be continued in
postpartum period.
• Postpartum i.v. Furosemide should be given
aggresively for early recovery.

34. Antihypertensive medication

35. Beta blockers

36. Mechanism of action
Beta 1 Beta2 Beta3
Heart
JG cells in kidney
Blood vessel
Bronchi
Uterus
Liver, GIT, eye
Urinary tract
Adipose tissue
1. Increases heart rate,
cardiac stimulation
2. Increases renin
release from kidney
1. Vasodialation- fall in
BP
2. Bronchodilatation
3. Relaxex detrussor
muscle
4. Intestinal relaxation
5. Lipolysis---FFA
6. Glycogenolysis—
hyperglycemia

37. Alpha1 Alpha2
Postjunctional on effector organs Prejunctional on nerve endings
Vasoconstriction Vasoconstrictor
Decrease central sympathetic outflow
Inhibit transmitter release

38. Effects of beta blockade
Dec. Myocardial
Contractility[b1]
Dec.Heart Rate[b1]
Dec. Cardiac Output
Decreases heart rate
Dec. BPDec. in NA Release Due to
Blockade of presynaptic β
Receptor
Blockade of Central β
Receptor ,reduces
sympathetic outflow
Dec. in Renin
Release[b1]
Dec. Total Peripheral Resistance

39. • Labetalol (Normadate)
• 1st Adrenergic Antagonist Capable of
blocking both α1 & non selective β receptor
(β1 , β2) and β2 agonistic activity
• α1 Receptor -) on Blood vessels -) Vasoconstriction
• β2 Receptor -) on Blood Vessels -) Vasodilatation
-) On bronchi -) Bronchodilatation
• β1 Receptor -) on Heart -) Contractility
• Reduces cardiac output and total peripheral
resistance
• α:β blocker ratio given orally - 3:1
Intravenously - 1:7

40. • Oral 100mg BD may be increased upto 2400mg
daily. Maintenance dose is usually 200-400mg
twice daily.
• I/v infusion (hypertensive crisis)
• 20 mg. slow I/v bolus – wait for 10 min. if no
response than give 40 mg. slow bolus – 10 min –
80 if no response may give total 300 mg. per
episode or constant infusion 1-2mg /min
• Target Diastolic BP is 90-100 mmhg.

41. ABSORPTION & METABOLISM
• Completely absorbed from the gut & extensive 1st pass
metabolism occur so its bioavailability is only 20%.
• Drug Rapidly & Extensively metabolized in liver, so
avoid in hepatic dysfunction.
• Half live – 8 hrs.
Side effects
• Tremor, Headache, asthma, Postural
hypotension , CCF Bradycardia, lethargy,
fatigue, sleep diturbances
C/I –
Hepatic Disorder, Asthma, CCF, Heart disease
These are also associated with SGA infants

42. PROPANOLOL
•It is a non selective Beta adrenergic receptor
blocker .
•Used in the dose of 80 – 240 mg in divided doses.

43. Side effects
Maternal
- Hypotension
- Sodium Retention
- Bradycardia
- Bronchospasm
- Cardiac Failure
- Hypoglycemia
Fetal
- Bradycardia
& impaired
fetal response
to hypoxia
- IUGR (Ist
&2nd)
Neonatal
- Hypoglycemia
C/I
- Bronchial Asthma
- Renal Insufficiency
- DM

44. METHYLDOPA
It’s a selective alpha 2 agonist which acts on
central alpha2 receptors and decrease efferent
sympathetic activity.
It has minimal effect on heart rate.
Mainly decrease tpr
Renal blood flow is maintained so can be used in
kidney patients
Dose – 250 mg BD, TD, QDS upto maximum 2
gm daily{ 0.5-3G/DAY ORALLY IN TWO-
THREE DIVIDED DOSES}
durAtion of action :8hrs

45. ADRs.
1- Maternal - Postural hypotension
- Sedation & drowsiness
- Dryness of mouth
- hyperprolactenemia
- Gyancomastia
- Galactorrhoea
- Hemolytic Anaemia
- Coombs positive
- Sodium retention
- Hepatic dysfunction
Fetal - Intestinal Ileus
Contraindication – Hepatic Dysfunction
- Psychic pt. depression
- CCF

46. CALCIUM CHANNEL BLOCKER
• Nifedipine –(Depin)
• It is direct Arteriolar Vasodilator
• It acts by blocking L – type of calcium channel.
• Inhibit calcium influx in heart bld. Vessel & Non vascular
smooth muscle ----resulting in decrease PVR
• Mild Diuretic effect and tocolytic effect.
• Dose
• Htn crisis:10 mg initial dosesf/b repeat doses after 30
min
• Usual oral dose 10-30 mg orally every 6 hrs,increased upto
20 mg every 4 hrs(max 120 mg/day)
• Dose has to be titrated by BP response the aim is to bring
down the diastolic BP to b/w 90-100mg. But not lower.

47. It absorbs immediately and reaches peak level in
30 mins.
s/e
-Flushing, - Ankle Oedema
-Hypotension - Headache
-Tachycardia - Inhibition of labour.
-80% nifedipine eliminated by kidney.
C/I
Simultaneous use of mgso4 Could be hazardous
due to synergistic effect.
It hamper the diabetes control by decreasing
insulin release.

48. Nifedipine
• Sublingual nifedipine never to be given as it
cause sudden maternal hypotension and foetal
distress due to placental hypoperfusion.

49. • Hydralazine – 25 mg tablet and 20 mg injection per
amp.
Dosage and administration
Slow IV-5 mg diluted in 10 ml of Normal saline slow IV
at 15-20 min interval until diastolic BP comes down to
between 90-110 mm of Hg. Maximum cumulative dose is
30 mg/ treatment cycle
oral :-twice daily in doses of 40-200 mg
iv infusion in hypertensive crisis.5 mg i/v bolus f/b
infusion 25 mg in 200 ml ns
Onset of action is rapid within 10mins after i/v injection.
It peaks in 3-4hr and has total duration of action 6-
12hours
Monitoring Besides other things close monitoring of
pulse is a must because this drug can cause troublesome
tachycardia and palpitation.
Mechanism of action Cause direct relaxation of
arteriolar muscle.

50. Pharmacokinetics
• Well absorbed orally
• Peak occurs in 1-2 hrs.
• Is subjected to 1st pass metabolism in liver it metabolized
by acetylation which exhibit bimodal distribution in
population
Slow Fast acetylates
• (Bioavailability is higher)
• Slow acetylation is better in reducing bp
• But more prone to lupus syndrome
• T half – 1-2 hrs.
• But hypotensive effects last longer 12 hrs.

51. ADRs
• Maternal – Hypotension
- Tachycardia
- Arrhythmia
- Palpitation
- Lupus like syndrome
- Fluid retention
Fetal - Reasonably safe
Neonatal - Thrombocytopaenia

52. NITROPRUSSIDE
• Dose – I/V infusion 0.25-8 mcg/kg/min.
• Rapidly acting – brief duration of action (2-5 min.)
• Side effect.
• Maternal – Nausea, vomiting, severe hypotension
• Disorientation, perspiration
• Fetal – Due to cyanide & thiocyanate
Drug of last resort for Acute HTN,
Should be used in critical care unit for very short time
(10 min)

53. NITROGLYCERINE
• Predominant venodilator,less arteriol dilator
• Dose – I/V infusion 5 mcg/min to be increased
at every 3-5 min. up to 100 mcg/min.
• ADRs – Tachycardia - Palpitation
- Throbbing headache - flushing
- Dizziness - Methaemoglobinaemia
Used in hypertensive Crisis for short time. only
C/I in hypertensive Encephalopathy as it
increase blood flow and I/C pressure.
Fetal cynaide toxicity occur after 4 hr

54. • Anti Haemoconcentration therapy
Ringer lactate solution is fluid of choice
Dose – 60 to 120 ml per hours .plasma volume
expanders are contraindicated in eclampsia and
severe pre-eclampsia.

55. Drugs for prevention of pre-eclampsia
• Low dose aspirin 75 mg
• Calcium – 1000mg
• Anti oxidant
▫ Vitamin E- 400 mg
▫ Vitamin C – 1000 mg/day

56. Anti Convulsant therapy in Pregnancy
• MgSO4
• Mode of action
-Reducedpresynaptic release of NT glutamate
-blockade of NMDA receptors
-potentiation of adenosine action
-improved calcium buffering by mitochondria
-blockage of calcium entry via voltage gated channel
Dose- Intramuscular protocol (Pritchard regimen)
Loading dose – 4gm 50% MgSO4 in 12 cc Ns as
20% sol.
I/V slowly over 3-5 min at rate of 1gm/min
I/m part – 10 gm of 50% solution – injected deep Im into
two buttocks (5 gm in each buttock) with 7 cm long 20-
guage needle since injection is very painful one may add 1
ml of 2% lignocaine to each injection dose

57. Maintenance dose – 5 gm of 50% solution deep Im in
alternate buttocks every 4 hours, after assuring
-patellar reflex present
-respiration not depressed
-UO exceed 100 ml
If fit recur and it is not yet 4 hr after the last
injection, another shot of MgSO4 2 gm have to be
given IV right then
* Intravenous protocol – (Zuspan or sibai)
Loading – 4-6 gm of 25% solution injection slowly IV
over 15-20 min.
If convulsion persist give another 2 gm I/V slowly.

58. Maintenance dose – Add 20 gm of MgSO4 (four 10
ml amp of 50% solution) to 1000 ml of normal
saline solution at rate of 2g/hr.RCOG guideline
recommends 1 gm/hr.
Measure serum magnesium levels if S.creatinine>1
mg/dl
Criteria for monitoring magnesium toxicity
 Urine output should be at least 30 ml/hours
 Deep tendon reflexes should be present
 Respiration rate should be >14 breaths/min
 Pulse oximetry should be  96%

59. Mg level kept b/w 4-7 meq/lit
Duration of MgSO4 therapy continued upto 24 hr
after delivary or last convulsion
Supplement to MgSO4 if fits not controlled by
MgSO4 IV barbiturate,midazolam,lorazepam.
Antidote to MgSO4 – calcium gluconate 1 gm
(10ml of 10% solution) is to be given IV over 2-3
min.
TOXICITY :
Patellar reflex disappear: 10 meq/l
Breathing weakens :above 10 meq/l
Respiratory paralysis: 12meq/l
 ***inhibition of uterine contractions occur at8-
10 meq/l

60. • Magnesium is cleared almost by renal
excretion,the dosage will be excessive if GFR is
decreased
• Initial 4 gm loading dose can be safely
administered regardless of renal function.,
• Mag decreases SVR and MAP.

61. Phenytoin – Centrally acting anticonvulsant
Dose – eclampsia – 10 mg/kg IV at rate not more
than 50 mg/min followed 2 hours later by 5
mg/kg.
Maintainence dose :100 mg ivevery 6-8 hrs
Prophylaxis: 100 mg doses iv or im every 4 hrs
Side effect – maternal hypotension, cardiac
arrythmia, phlebitis at inj site.
Fetal hydratoin syndrome – seen in 5-10% off
springs.

62. Lytic cocktail
• Chlorpromazine 25mg and Pethidine 100mg in
20ml of 5%d i/v
• 50mg chlorpromazine and 25mg promethazine
i/m followed by 50mg chlorpromazine and 25mg
promethazine i/m alternatively 4 hourly for 24hr
• 100mg pethidine in 10%dextrose drip at 20-30d
/min for 4hr following last fit.

63. diazepam
• 10-40mg i/v f/by 40mg in 500ml of 5%d at rate
of 30d/min