Drugs in pregnancy

‫بسم‬‫هللا‬‫الرحمن‬‫الرحيم‬
Drugs in pregnancy
Ahmad abdul kareem

 Drugs in pregnancy
 Assess risk/benefit ratio for the mother-fetus pair.
 Avoid non-essential drugs.
 Where drug treatment is clinically indicated, select an
effective agent with the best safety profile.
 Use the lowest effective dose for the shortest possible time.
 Provide timely and accurate counselling to help avoid
unfounded maternal fears about drug safety that may otherwise result
in non-adherence with drug therapy or unnecessary pregnancy
termination.
 Use the statement ‘avoid all drugs in the first trimester where
possible’ cautiously as drug exposure in the second and third
trimesters may still result in fetal harm.
 Remember that the harmful effects of a drug on the fetus may differ
depending on the trimester of exposure.
Key points

 Normal physiologic changes that occur during pregnancy may
alter medication effects, resulting in the need to monitor and,
sometimes, adjust therapy.
1. maternal plasma volume, cardiac output, and glomerular
filtration increase by 30% to 50%.
2. As body fat increases during pregnancy.
3. Plasma albumin concentration decreases.
MATERNAL PHARMACOKINETIC
CHANGES IN PREGNANCY

4. Nausea and vomiting, as well as delayed gastric emptying,
may alter the absorption of drugs.
5. Likewise, a pregnancy-induced increase in gastric pH may
affect the absorption of weak acids and bases.
6. Higher levels of estrogen and progesterone alter liver
enzyme activity and increase the elimination of some
drugs but result in accumulation of others.
continued

 A teratogen is defined as any agent that results in structural
or functional abnormalities in the fetus, or in the child after
birth, as a consequence of maternal exposure during
pregnancy.
 The teratogenic mechanism for most drugs remains
unclear(idiosyncratic), but may be due to the direct effects of
the drug on the fetus and/or as a consequence of indirect
physiological changes in the mother or fetus.
Teratogen

 Teratogenic risk is determined largely by timing of drug expo-
sure :
 Establishment of full implantation of the fertilized egg takes 1
to 2 weeks.
Teratogenic exposure during this stage elicit an ‘all-or-nothing’
response, leading either to death of the embryo or completely
normal development of the fetus.
Pathophysiology

continued
• Embryonic stage (weeks 3-8 post-conception)
The critical time for organogenesis is during the first 8 weeks of
pregnancy.
Organogenesis occurs predominantly during the embryonic stage
and, with the exception of the central nervous system, eyes, teeth,
external genitalia and ears, is complete by the end of the 10th week
of pregnancy. Exposure to drugs during this critical period
therefore represents the greatest risk of major birth defects.

 For this reason, women are often advised to avoid or
minimize all drug use in the first trimester whenever
possible.
 After 8 weeks, most teratogenic effects are related to
fetal growth restriction or functional deficits such as
mental retardation.
continued

Drugs during pregnancy can be categorized as:
 A : Fetal risk not revealed in controlled studies in humans
 B : Animal studies have revealed no evidence of harm to the
fetus, while, there are no adequate studies in pregnant women,
or animal studies have shown an adverse effect, but studies in
pregnant women have failed to demonstrate a risk to the fetus.
 C : Animal studies have shown an adverse effect and there are no
adequate and well-controlled studies in pregnant women.
So

 D : Studies, adequate well-controlled, in pregnant women
have demonstrated a risk to the fetus. However, the benefits
of therapy may outweigh the potential risk.
 X : Studies, adequate well-controlled or observational, in
animals or pregnant women have demonstrated positive
evidence of fetal abnormalities. The use of the product is
contraindicated in women who are or may become
pregnant.
continued

 Six Principles of Teratology which are still applied today :
1. Susceptibility to teratogenesis depends on the genotype of the
conceptus and the manner in which this interacts with adverse
environmental factors.
2. Susceptibility to teratogenesis varies with the developmental stage at
the time of exposure to an adverse influence.
3. Teratogenic agents act in specific ways on developing cells and tissues
to initiate sequences of abnormal developmental events.
Wilson's 6 principles

4. The access of adverse influences to developing tissues depends
on the nature of the influence. Several factors affect the ability of
a teratogen to contact a developing conceptus, such as the
nature of the agent itself, route and degree of maternal
exposure, rate of placental transfer and systemic absorption, and
composition of the maternal and embryonic/fetal genotypes.
5. There are four manifestations of deviant development (Death,
Malformation, Growth Retardation and Functional Defect).
6. Manifestations of deviant development increase in frequency and
degree as dosage increases from the No Observable Adverse
Effect Level (NOAEL) to a dose producing 100% Lethality (LD100).
continued

 Although once thought to be a barrier to drug transfer
 the placenta is fundamentally the organ of exchange for a
number of substances, including drugs, between the mother
and fetus. Most drugs move from the maternal circulation to
the fetal circulation by diffusion. Certain chemical properties,
such as lipid solubility, electrical charge, molecular weight, and
degree of protein binding of medications, may influence the
rate of transfer across the placenta also.
TRANSPLACENTAL DRUG TRANSFER

 Drugs with molecular weights less than 500 Da readily cross the
placenta, whereas larger molecules (600–1,000 Da) cross more
slowly.
 Lipophilic drugs, such as opiates and antibiotics, cross the placenta
more easily than do water-soluble drugs.
 fetal albumin increases during the course of pregnancy
 Fetal pH is slightly more acidic than maternal pH, permitting weak
bases to more easily cross the placenta. Once in the fetal circulation,
however, the molecule becomes more ionized and less likely to
diffuse back into the maternal circulation.
continued

 Although some drugs have the potential to cause teratogenic
effects, most medications required by pregnant women can be used
safely.
 There are many misconceptions about the association of medications
and birth defects.
 The overall incidence of congenital malformations is approximately
3% to 5%.
 medication exposure accounts for less than 1% of all birth defects.
 Genetic causes are responsible for 15% to 25%.
 other environmental issues (e.g., maternal conditions and infections)
account for 10%, and the remaining 65% to 75% of congenital
malformations result from unknown causes.
Myths v.s Facts

PREGNANCY-INFLUENCED ISSUES
ACUTE CARE ISSUES IN PREGNANCY
CHRONIC ILLNESSES IN PREGNANCY
LABOR AND DELIVERY
Therapy needed in pregnancy due
to

Constipation : occurs commonly in pregnancy.
 use of stool softener is appropriate.
 Lactulose, sorbitol, and bisacodyl are acceptable treatments
but should be reserved for occasional rather than routine
use.
 Senna can be used occasionally. Cat C
 Castor oil and mineral oil should be avoided. Cat X
can induce labor and can cause vomiting and dehydration
PREGNANCY-INFLUENCED ISSUES

Gastroesophageal reflux disease
 Drug therapy can be initiated with aluminum, calcium, or
magnesium antacid preparations
 Sucralfate is another option
 and evidence supports the use of ranitidine and cimetidine.
 Literature on the use of famotidine and nizatidine is limited
 metoclopramide, lansoprazole,omeprazole, are viable options.
 sodium bicarbonate risky cat C

Hemorrhoids : Therapy is generally conservative; high
intake of dietary fiber, adequate oral fluid intake, and use of
sitz baths are helpful.
 Topical anesthetics, skin protectants, and astringents can
be used. Other options for refractory hemorrhoids include
rubber band ligation, sclerotherapy, and surgery.

 Nausea ,vomitting &hyperemesis gravidarum:
 Vitamins:B6 ,B12(cyanocobalamine)
 Antihistamines (meclizin,cyclizine,dimenhydrate,
 doxylamine) have not proved to be toxic except
amobarbital.
 Phenothiazines (chlorpromazine)& metoclobromide
 Ondanstron (limited studies)
 Steroids(dexamethazone,prednisolone)effective +increase
risk of cleft lip(in 1st trimester).
 Ginger has shown efficacy for hyperemesis.

 GESTATIONAL DIABETES :
 Mx = diet control(decrease calory for obese)
+/- drug therapy. Exercise(as possible).
 Drug of choice =insulin, if insulin can’t be used
(for one reason or another):
 Glyburide :oral sulphonylurea does not cross
the placenta or metformin (inadequately
studied)

 HYPERTENSION(preeclampsia):
 Mx =diet control+/- drug therapy.
 Preventive measures : 1g/day Ca++ supplements,,
 Low dose aspirin(<325mg/day)for high risk women.
 Drugsfor severe hypertension:
 Maintanence : methyldopa,,nifedipine
 ACE inhibitors : risky(oligohydramnia,fetal anurea renal
agenesis)
 Acute settings: labetalol , hydralazine.
 Avoid : nimodipine, Mg sulphate (except for eclampsia
prophylaxis) & high-dose diazoxide.

 THROMBOEMBOLISM:
 Warfarin : avoid whenever possible(goup D,X); it can cause
CNS anomalies, deformed nose & stippled epiphysis(early in
pregnancy) ,fetal & neonatal bleeding(later in pregnancy).
 Acute thromboembolism: LMWH or unfractioned
heparin(during pregnancy &6 wks postpartum)
 Antiphospholipid syndrome: LMWH, unfractioned heparin
&/or aspirin.
 Women with prosthetic valves:LMWH, unfractioned heparin

Alternative regimen:
Beginning of
pregnancy
Heparin
product
13 wks
change to warfarin
Middle of 3rd
trimester
return to
6 wks post
partum
High-risk women with prosthetic heart valves may also
receive aspirin therapy in doses of 75 to 162 mg/day

URINARY TRACT INFECTIONs :
Asymptomatic bacteruria, cystitis and pyelonephritis
Antibiotic selection should be based on urine culture
sensitivities, if known.
Often, therapy must be initiated on an empirical basis, before
culture results are available.
This requires clinical knowledge of the most common
organisms and their practice-specific or hospital-specific
sensitivities to medications.
ACUTE CARE ISSUES IN PREGNANCY

 Oral antibiotics are the treatment of choice for asymptomatic
bacteriuria and cystitis. Appropriate oral regimens include the
following:
 Cephalexin 500 mg 4 times daily
 Ampicillin 500 mg 4 times daily
 Nitrofurantoin 100 mg twice daily
 Sulfisoxazole 1 g 4 times daily
DCIM

Pyelonephritis :
 Current regimens are :
 First-line therapy
 Nitrofurantoin monohydrate/macrocrystals 100 mg orally twice
daily for 5-7 days or
 Amoxicillin 500 mg orally twice daily for 5-7 days or
 Amoxicillin-clavulanate 500/125 mg orally twice daily for 3-7 days or
 Cephalexin 500 mg orally twice daily for 3-7 days or
 Cefuroxime 250 mg orally twice daily for 3-7 days
 Second-line therapy
 Fosfomycin 3 g orally as single dose with 3-4 oz. of water
 Macrolides are safe but not first-line agents for UTI in pregnancy.

 The most common m.o is E.coli which has resistence to many drugs:
Ampicillin(28-29%),co-trimoxazole(31%),1st generation cephalosporins
(9-19%).
 Risks with use of antibiotics :
 Tetracyclines:fetal teeth &bones abnormalities& congenital defect.
 Trimethoprim(in 1st trimester):facial defect &cardiac defects.
 Cloramphenicol:gray baby syndrome.
 Sulphonamides in 3rd trimester: jaundice &kernicterus, in the mother,
H. anemia if she has G6PD deficiency.

 Fluoroquinolones are contraindicated in pregnancy
myelomeningocele, hydrocephaly, hypospadias, maldescended
testes, inguinal hernia, bilateral hip dysplasia, and atrial septal
defects.
 Nitrofurantoin is safe &effective(&can be used once daily as
prophylaxis) but with poor tissue penetration &so it has limited
use in treatment of pylonephritis.
 It’s not used in last several wks of pregnancy(due to hemolytic
effects on fetal/neonatal blood because of glutathione instability
in their immature RBCs.

 SEXUALLY TRANSMITTED DISEASES(STD) :
 STDs in pregnant women range from :
A. infections that may be transmitted across the placenta and
infect the infant prenatally (e.g., syphilis).
B. to organisms that may be transmitted during birth and cause
neonatal infection (e.g., Chlamydia trachomatis, Neisseria
gonorrhoeae, or herpes simplex virus)
C. to infections that pose a threat for preterm labor (e.g.,
bacterial vaginosis).

 Always treat both partners.
Neisseria gonorrhoeae
 The treatment of choice is ceftriaxone 125 mg i.m as a single
dose or cefixime 400 mg orally in a single dose.
 For women unable to use a cephalosporin, spectinomycin 2 g
i.m as a single dose is appropriate.
 Quinolones or tetracyclines should not be used.

Chlamydia trachomatis:
 The recommended treatment of C. trachomatis cervicitis is
azithromycin 1 g orally as a single dose or
 amoxicillin 500 mg three times daily for 7 days.
 Erythromycin base or ethylsuccinate regimens can be
considered as alternatives.
 Erythromycin estolate should be avoided because of an
increased risk for hepatitis

Syphilis:
 the drug of choice is penicillin (it prevents transmission to the
fetus and in treating the fetus, if already infected).
 The dose and route of administration are determined by the
stage of syphilis and are the same for pregnant women as for
other patients.
 No alternatives for penicillin are acceptable for pregnant
women allergic to penicillin; therefore, penicillin skin testing
and desensitization are required.
 There is a risk of premature labour &/or fetal distress for
women taking the drug in the 2nd half of pregnancy(due to
jarish-herixhimer reaction.

 Genital Herpes :
 Neonatal herpes often occurs in infants born of women
lacking clinical evidence of genital herpes.
 Primary infection near the time of delivery carries 30-50%
risk of transmission.
 In recurrent herpes infections at term or an initial episode
during the first half of the pregnancy, the risk of
transmission is less than 1%.
 However, because recurrent herpes is more common than
initial episodes during pregnancy, it remains the cause for
most cases of neonatal transmission.

 The usefulness of antiviral agents for preventing
transmission of genital herpes to pregnant women has not
been studied.
 Acyclovir , valacyclovir and famciclovir
 Acyclovir use during late pregnancy has been associated
with a reduced frequency of cesarean section because of
fewer recurrences.
 No data suggest benefit of treatment for women who are
seropositive for herpes simplex virus but have not
experienced a clinical episode.

Bacterial Vaginosis
 Although not a STD, bacterial vaginosis is a risk factor for premature
PROM, preterm labor, spontaneous abortion, and postpartum
endometritis.
 Treatment is the same as in nonpregnant patients:
 Metronidazole at 250-500 mg orally twice per day for 7 days
 or clindamycin 300 mg orally twice per day for 7 days are
recommended.
 clindamycin cream should be avoided during the second half of
pregnancy because it can increase the risk of premature birth.
 Oral therapy is preferred for pregnant women because of the
possibility of subclinical upper genital tract infection.

Antifungal: topical, vaginal:
 Topical : the following agents can be used safely:
 Clotrimazole, Naftiﬁne , Nystatin, Amphotericin B Ciclopirox
Haloprogin Oxiconazole Terbinaﬁne. The other topical agents
considerd cat C
 Vaginal agents :
 Nystatin cat A
 Clotrimazole cat B
 Miconazole Butoconazole Terconazole Tioconazole : Cat C

Systemic antifungal :
 Systemic antifungal agents have traditionally been regarded as
toxic medications, and their use in pregnancy has been limited to
life-threatening fungal infections.
 Fluconazole : should be avoided multiple congenital anomaly
 Itraconazole :used only in life threatining situation.
 Ketoconazole, Posaconazole :use if risk outweighs benefit.
 Amphotericin B : not known to be harmful but manufacturer
advice to avoid .some resources says it is cat B

Antiparasitic agents: all of them are cat C except nitazoxanide
wich is cat D.
Anthelminthic agents:
praziquantel cat B
Albendazole, mebendazole , ivermectin cat C
Diethylcarbamazine cat X

HEADACHE
Headaches in pregnant women can be classified as primary
(tension, migraine) or secondary (trauma, infection) .
 Acetaminophen (with or without codeine), codeine, or other
narcotic analgesics(Meperidine, morphine) can be used to treat
headaches.

 NSAIDs are considered safe (Ibuprofen Naproxen) during the
first trimester but are generally contraindicated in late
pregnancy.
 sumatriptan : controversal but it is cat C and may be used.
 Dihydroergotamine, Ergotamine are contraindicated in
pregnancy

 ALLERGIC RHINITIS AND ASTHMA:
 Rx of asthma is considered safer than risks to the
fetus from untreated asthma.
 A short-acting β2- agonist should be available to use
for quick relief of symtoms.
 Mild intermittent asthma: require only a short-acting,
inhaled β2-agonist(albuterol is the preferred agent)
CHRONIC ILLNESSES IN PREGNANCY

 Mild persistent asthma: Low-dose inhaled corticosteroids are
Rx of choice (budesonide is the preferred agent).
 alternatives to steroids:cromolyn(less efficacy),leukotrines
receptor antagonists (less experience with their use) or
theophylline (more potential toxicity than inhaled steroids).
 Mg sulphate is safe in pregnancy (dilate airway by smooth
muscle relaxation).
 Severe asthma exacerbation :epinephrine(with risk of cong.
malformations,fetal tachycardia & vasoconstriction of
uteroplacental circulation).

 For moderate persistent asthma; either:
 low- dose inhaled corticosteroids + a long-acting β2-
agonist(Formoterol,salbutamol)
 or an increase in the dose of the inhaled corticosteroids.
 For severe persistent asthma, the inhaled corticosteroid dose
should be increased to the high-dose range.
 Addition of systemic corticosteroids may be warranted if
symptoms continue.

Allergic rhinitis :
Beclomethasone and budesonide are most widely studied.
nasal cromolyn &1st generation antihistamines:
(chlorpheniramine,tripelennamine &hydroxyzine)are also
considered 1st line choice.
2nd generation (loratidine &cetirizine) do not appear to
increase risk to the fetus.
Oral decongestants (pseudoephedrine) may be associated
with an increased risk for gastroschisis.
Use of an external nasal dilator, short-term topical
oxymetazoline, or inhaled corticosteroids may be preferable
to use of oral decongestants

DERMATOLOGIC CONDITIONS :
 topical agents with minimal pregnancy risk:
 bacitracin, benzoyl peroxide(for acne), ciclopirox(antifungal) ,
mupirocin (antibacterial), permethrin (for lice/scabies), and
terbinafine (antifungal).
 Systemic agents considered safe include : cyproheptadine,
dicloxacillin, nystatin.
 Lidocaine and lidocaine + epinephrine can be used topically
during pregnancy
 acitretin, fluorouracil, isotretinoin, methotrexate, and
thalidomide are contraindicated

EPILEPSY: antiepileptic drugs(AED):
 Major malformations occur in 4% to 6% of offspring of epileptic
women taking benzodiazepines, carbamazepine, phenobarbital,
phenytoin, or valproic acid.
 Lamotrigine has been associated with an incidence of oral cleft
palate and/or lip of one case per 113 exposed.
 Combination regimens of antiepileptic drugs are associated with
higher malformation rates.

 Use antiepileptic drug monotherapy, if possible, and
optimize any drug therapy prior to conception.
 Medication change exclusively to minimize
teratogenic risk & prior recommendation to switch
from other antiepileptic drugs, is no longer
recommended.
 Drug withdrawal, if planned, should be attempted at
least 6 months before conception is attempted

 the mother should receive supplementation with 10 mg oral
vitamin K1 daily during the last month of gestation.
 In addition, all women with epilepsy should take folic acid
supplementation of 0.4 to 5 mg daily.

Cardiovascular diseases
HYPERTENSION
 ARBs, ACE inhibitors are cat(C/D).
 renal dysgenesis or death (if used in 2nd & 3rd trimesters)
 increased risk of cardiovascular and CNS malformations when
used in the first trimester.
 Diuretics avoided in pregnancy, as they prevent the physiologic
volume expansion. They may be used in states of volume-
dependent hypertension, such as renal or cardiac disease.

Three treatment options are available in cases of mild chronic
hypertension in pregnancy:
 Antihypertensive drug may be discontinued, with subsequent
close observation of blood pressure.
 If a woman is on unacceptable agent in pregnancy, she may be
switched to an alternative antihypertensive agent preferred for
use in pregnancy.
 If a woman is on pharmacologic treatment with an agent
acceptable in pregnancy, she may continue her current
antihypertensive therapy.

Valvular heart diseases:
 hydralazine, digoxin, adenosine, and procainamide can be safely
used in pregnancy.
 amiodarone, and nitroprusside are contraindicated during
pregnancy regardless of the indication.
 Most other medications carry a potential risk to the fetus and
should only be used when the maternal benefit outweighs the
fetal risk.

Coronary Artery Disease
 Low-dose aspirin is safe but prolonged use of 100 mg aspirin can
cause increased maternal bleeding complications and low birth
weight.
 Beta-blockers are the drug of choice in pregnancy(safe).
 Nitrates and calcium channel blockers should be used with
caution to avoid maternal hypotension.
 Thrombolytic therapy has limited data in pregnancy. No reports
of teratogenic effects exist, but an increased risk of maternal
hemorrhage exists

Beta-blockers :
Atenolol cat D
Metoprolol cat C (D at term or prolonged use)
Nadolol cat C (D at term or prolonged use)
Propranolol cat C (D at term or prolonged use)
Timolol cat C (D at term or prolonged use)
 Coronary reperfusion by percutaneous transluminal coronary
angioplasty or coronary bypass graft surgery has been reported
with favorable outcomes.

Respiratory system
 ipratropium bromide can be used safely
 Common antibiotics used for respiratory infections:
 penicillin, cephalosporins, and erythromycin.
 Antibiotics that have relative contraindications include:
sulfonamides(kernicturus) , trimethoprim (folate deficiency) ,
aminoglycosides (fetal ototoxicity) , nitrofurantoin (g6pdd),
tetracyclines (discoloration of teeth), and quinolones (cartilage
damage), chloramphenicol(not adivsed because of gray baby
syndrom) ,
 Vancomycin ,teicoplanin , daptomycin and linezolids are adviced
only if risk outweighs benefit.

Tuberculosis:
 Pregnant women with active TB should be treated, even in the
first stage of pregnancy.
 Isoniazid, rifampin, ethambutol and pyrazinamide may be used.
 Streptomycin should not be used, because it has been shown to
have harmful effects on the fetus (has the heighest risk of
ototoxicity).

MENTAL HEALTH CONDITIONS
 An estimated 500,000 pregnancies each year involve women
with psychiatric illnesses (either newly or previously diagnosed) .
 Anxiety disorders, including panic disorder, obsessive
compulsive disorder, generalized anxiety disorder,
posttraumatic stress disorder, social anxiety disorder, and
phobias, are the most commonly occurring psychiatric illnesses.
 Depression, Schizophrenia eating disorder are less common than
anxiety disorders.

 All TCA are cat C
 except nortriptyline , imipramin cat D
 Use only when risk outweigh benefit
 The SSRI are the drugs of first choice in the general
population and are widely used by pregnant women.
 About one to two babies per 1,000 develop persistent
pulmonary hypertension when used after week 20 of
pregnancy.

 Another risk associated with use of SSRIs late in pregnancy is a
withdrawal reaction in the infant consisting of irritability and
difficulty with feeding and breathing.
 Finally, an epidemiologic study suggests that 1st trimester use
of paroxetine may be associated with an increased risk for
cardiac defects in the infant.

 Benzodiazepines : category - D or X &
 increases risk for oral clefts.
 Benzodiazepine use in the third trimester can be associated
with infant sedation and withdrawal symptoms.
 “floppy baby syndrome,” consisting of low Apgar scores,
hypothermia, poor muscle tone, and poor temperature
adaptation.
 Chlordiazepoxide seem to be safe in pregnancy.
 flurazepam, temazepam, and triazolam (category X).
 Avoidance of alprazolam during pregnancy seems prudent.

 Lithium : avoid if possible in first trimester (Ebstein anomaly ).
 needs dose adjustment in 2nd and 3rd trimesters.
 Other reported side effects in the newborn include “loppy baby
syndrome,” nephrogenic diabetes insipidus, hypoglfycemia,
cardiac arrhythmias, thyroid dysfunction, polyhydramnios, and
premature delivery
 Chlorpromazine, haloperidol, and perphenazine have long
histories of use during pregnancy .

Atypical antipsychotics : use of them in pregnant women is
controversial.
 olanzapine and clozapine have been associated with weight gain
and an increased incidence of glucose intolerance, which have
implications for poorer obstetric outcomes.
 Other agents, such as quetiapine, risperidone, aripiprazole, and
ziprasidone, have been used less in pregnancy, so only limited
information is available. At present, atypical antipsychotics do
not appear to be safer than the typical agents.

THYROID DISORDERS
 levothyroxine if hypothyroidism is diagnosed can be used safely
with doses more than non-pregnant woman.
 thioamides (e.g., propylthiouracil, methimazole)
 thioamides can crosses placenta.
 Radioactive Iodine-131 is contraindicated because of the risk of
thyroid damage in the fetus.
 The best time to do surgery for thyroid disorders is during the 2nd
trimester.

 Anti-neoplastic : all of them are teratogen and
should be avoided unless risk outweigh benefit.

Tocolytic Therapy
 β-agonists, magnesium, Ca channel blockers, NSAIDs have
similar effectiveness in prolonging pregnancy from 48 hrs to 1
week.
 The β-agonists(terbutaline and ritodrine) have been used as
tocolytics.(only ritodrine had FDA approval for this use but
has been withdrawn from the market).
 Mg sulphate: Maternal side effects are rare but can include
pulmonary edema.
 At toxic levels, hypotension, muscle paralysis, tetany, cardiac
arrest, and respiratory depression may occur
LABOR AND DELIVERY

 Nifedipine is associated with fewer side effects than magnesium
or β-agonist therapy.One concern with the use of nifedipine is
the potential negative effect on blood flow between the
placenta and the uterus.
 NSAIDs (such as indomethacin) have been used for tocolysis
with increased rate of premature constriction of the ductus
arteriosus.
LABOR AND DELIVERY

Corticosteroids
 betamethasone 12 mg intramuscularly every 24 hours for two
doses or
 dexamethasone 6 mg intramuscularly every 12 hours for four
doses to pregnant women between 26 and 34 weeks’ gestation
who are at risk for preterm delivery within the next 7 days.
LABOR AND DELIVERY

CERVICAL RIPENING AND LABOR INDUCTION
 Dinoprostone Prostaglandin E2 analogs [Prepidil gel , Cervidil
insert].
 Misoprostol : prostaglandin E1 analog.
 Mifepristone :is an antiprogesterone agent.
 Oxytocin is the most commonly used agent for labor induction
after cervical ripening.
Misoprostol : it is cat X and causes mobius syndrom.
LABOR AND DELIVERY

Pharmacologic Approaches to Labor Pain Management :
 parenteral opioids and epidural analgesia.
 parenteral Meperidine, morphine, and fentanyl are the most
commonly used agents
 Epidural analgesia involves introducing a catheter into the
epidural space and administering an opioid and/ or an anesthetic
(e.g., fentanyl and/or bupivacaine)
LABOR AND DELIVERY

 Another method is a combined spinal– epidural, which consists
of injection of a single bolus of an opioid into the subarachnoid
space, providing instant pain relief, and placement of an
epidural catheter with a local anesthetic.
 In comparison with epidural analgesia, parenteral opioids have
lower rates of oxytocin augmentation, result in shorter stages
of labor, and require fewer instrumental deliveries.
LABOR AND DELIVERY

 What are the implications of the disease itself for which the
drug is to be given regarding risk of anomaly?
 What are available sources of information about its use in
pregnancy and its effects on the fetus?
Certain questions need to be
answered---

After looking for answers to these questions proceed by
giving the following information to the woman:-
medication exposure accounts for less than 1% of all birth
defects.
Genetic causes are responsible for 15% to 25%.
other environmental issues (e.g., maternal conditions and
infections) account for 10%, and the remaining 65% to 75% of
congenital malformations result from unknown causes.
How to proceed with counseling

Wisdom and knowledge are the
key to good counseling and
prescribing in pregnancy!
fewer than 1% are due to prescribed
drugs !

Drugs in pregnancy

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