Labor & Delivery (Pharm) Flashcards
Significant uterine contractions prior to the completion of 37 weeks gestation?
Preterm Labor
What effects neonatal outcome?
Gestational Age.
What decreases uterine contractions to prolong time to delivery?
Tocolytic Agents; generally safe if used appropriately.
Used to delay delivery to decrease risks associated with premature delivery (2-7 days)?
Tocolytic Agents.
What gestational weeks are tocolytic agents most useful?
24-44 weeks gestation – benefits out-weight risks of tocolytics.
What gestational weeks is tocolytic therapy not recommended due to the lower risk of complications from premature delivery?
> 34 weeks gestation.
What situations do we avoid tocolytic therapy?
Intrauterine infection, fetal distress, maternal hemodynamic instability, vaginal bleeding.
Name the most commonly used Tocolytic Agents?
- Magnesium Sulfate.
- Beta 2-Agonists (Mimetics) – TERBUTALINE (Brethine).
- NSAIDs – INDOMETHACIN (Indocin).
- Calcium Channel Blockers (CCB) – Nifedipine (Adalat, Procardia); Dihydropyridine type.
Tocolytic MOA of Magnesium Sulfate?
Suppresses contraction of uterine smooth muscles by antagonizing intracellular Ca++
MOA of Magnesium Sulfate as a Seizure prophylaxis in Eclampsia/Pre-Eclampsia?
Decreases acetylcholine in motor nerve terminals.
Adverse effects of magnesium sulfate?
- Serious – maternal pulmonary edema, cardiac arrest.
2. COMMON – flushing, HA, nausea.
Serious toxicity from magnesium sulfate can be managed with?
Calcium Gluconate.
Contraindications/Cautions of magnesium sulfate?
Renal impairment, hepatitis, neuromuscular conditions.
What do we monitor with use of mag sulfate?
Mag levels, RR, DTRs, Renal function, Vital signs.
Dosing of mag sulfate?
IV loading dose (4-6g) with maintenance dosing titrated to maintain serum level of 4-8 mg/dL.
Stimulates Beta-2 receptors in uterine smooth muscle causing muscle relaxation?
Beta-2 Agonists – Terbutaline (Brethine).
How does Terbutaline (Brethine) cause muscle relaxation?
Decreases intracellular Ca and decreases contractile sensitivity to Ca.
Adverse Effects of Beta-2 Agonists?
- Increased incidence of maternal AEs compared to other tocolytics:
- -Arrhythmias, Tachycardia, Lyte abnormalities, Increased glucose, pulmonary edema. - Fetal/Natal AEs:
- -Tachycardia, blood glucose abnormalities.
Monitoring parameters with Terbutaline (Brethine)?
Serum Lytes, BG, Vitals (HR, BP, RR), S/Sx of pulmonary edema.
How is pulmonary edema avoided with use of Beta-2 agonists?
Adjustment of fluid and sodium intake.
Some studies indicated that this medication has a better neonatal outcomes and less maternal AEs than other tocolytics?
CCB – Nifedipine.
The precise mechanisms is uncertain but probable Ca channel inhibition in uterine smooth muscle?
CCB – Nifedipine.
Dosage and DI of Nifedipine?
- PO 10-30 mg Q4-6 hrs.
2. CYP450.
Monitoring parameters with Nifedipine (Adalat, Procardia)?
HR, BP, S/Sx of CHF, Peripheral edema.
Adverse effects of Nifedipine (Adalat, Procardia)?
**Fewer AEs than mag or terbutaline.
- (-) effect on blood flow between placenta and uterus.
- CV: Hypotension, flushing, EDEMA, palpitations, CHF.
- CNS: dizziness, HA.
- GI Upset.
- Derm: dermatitis, urticaria.
MOA of Indomethacin?
Inhibition of prostaglandins, closure of PDA (Patent Ductus Arteriosus).
What is involved in the the onset of synchronous uterine contractions, cervical ripening and the increase in myometrial sensitivity to oxytocin – in other words, the transition into labor?
Prostaglandins – Indomethacin inhibits the transition into labor (decreases preterm labor) by inhibiting prostaglandins (PGs).
Adverse effects of Indomethacin?
- Maternal – N, dyspepsia, dizziness, bleeding.
2. RARE/Serious neonatal complications – necrotizing enterocolitis, hemorrhage.
Dosing of Indomethacin?
1st dose – rectal suppository 50-100 mg followed by 25-50 mg PO Q6hrs.
Name some Antenatal Glucocorticoids?
- BETAMETHASONE – 12 mg IM Q24 hr x2 doses.
2. Dexamethasone.
What does Antenatal mean?
Before birth, prenatal.
Used to promote fetal lung maturation?
Antenatal Glucocorticoids.
MOA of Antenatal Glucocorticoids?
Act directly to upregulate PG production in fetal membranes at term.
What are some complications associated with prematurity? What is used to decrease these?
- RDS – Respiratory Distress Syndrome.
- Intraventricular Hemorrhage.
- Death.
**Antenatal Glucocorticoids such as Betamethasone.
Who is Betamethasone indicated for?
Pregnant women 24-34 weeks gestation who are at risk for preterm delivery within the next 7 days.
What increases the risk of premature delivery and risk of neonatal infection?
Women colonized with Group B Strep during pregnancy.
What is associated with invasive neonatal disease?
Infection with Group B Strep.
When is screening of Group B Strep in pregnancy completed?
- Vaginal and Rectal culture at 35-37 weeks gestation.
When do we treat a pregnant mother with Intrapartum antibiotics?
- (+) cultures.
- Previous infant with invasive Group B strep disease.
- Pt. w/unknown Group B status presents for delivery, and any of the following occur:
- -Temp >100.4.
- -ROM >18 hrs previous; ROM – rupture of membranes.
- - < 37 weeks gestation.
When do we start treatment for Group B Strep infection?
When ROM (Rupture of membranes) occurs and continue until delivery.
1st line treatment for Group B Strep?
Penicillin G – Pen G.
-5 million units IV followed by 2.5 million units Q4hrs until delivery.
Alternatives to Pen G?
AMPICILLIN, Cefazolin, Clindamycin, Erythromycin.
What to use if pt has a PCN allergy?
“PEC” – PCN, Erythromycin, Clindamycin, Vancomycin (best choice for GBS).
What Abx if Group B Strep is resistant to PCN (not an alternate)?
Vancomycin.
Name some Labor Induction Prostaglandin Analogs? What is another description of these meds?
- DINOPROSTONE (Cervidil) – Vaginal PG E2 (PGE2).
- Misoprostol.
*Cervical Ripening Agents.
When can we begin to use a labor induction PG analog?
When the cervix is favorable for labor.
Why is Dinoprostone favored over Misoprostol?
Misoprostol has a higher efficacy but a higher rate of AEs.
What do cervical ripening agents induce?
Contractions.
If contractions do not occur in the appropriate time frame after cervical ripening agents are administered, what is the next step?
Oxytocin is administered.
- Dinoprostone, contractions occur w/in 6-12 hrs.
- Misoprostol, contractions occur w/in 3 hrs.
MOA of Dinoprostone (Cervidil)?
Prostaglandin Analog
-PGs are involved in the onset of synchronous uterine contractions, cervical ripening and the increase in myometrial sensitivity to oxytocin use.
Indications for Dinoprostone?
- Labor induction/cervical ripening – pt’s near term w/indication for labor induction (Vaginal gel/insert).
- Termination of pregnancy from 12-20th week to evacuate the uterus in cases of missed abortion or intrauterine fetal death up to 28 weeks gestations (Vaginal suppositories).
What is the black box warning for Dinoprostone (Cervidil)?
It is ONLY to be used by medical providers in a medical facility.
Adverse effects of Dinoprostone (Cervidil)?
Fever, GI upset, back pain, abnormal uterine contractions.
Drug Interactions of Dinoprostone?
Oxytocin – incr. effects, wait 6-12 hrs after Dinoprostone gel or 30 mins after removal of insert.
Produces the rhythmic uterine contractions characteristic to delivery?
MOA of Oxytocin (Pitocin).
Indications for Oxytocin?
- Induction of labor at term.
2. Control of postpartum bleeding.
Drug Interactions of Oxytocin?
- Dinoprostone – wait 6-12 hrs.
2. Misoprostol – wait 3 hrs.
Maternal AEs of Oxytocin?
- CV – Arrhythmias, HTN.
- GI – N/V.
- GU – pelvic hematoma, uterine hypertonicity, uterine rupture.
Fetal AEs of Oxytocin?
- CV – Arrhythmias.
- CNS – brain damage, seizures.
- Other – jaundice, low APGAR score, retinal hemorrhage.
Contraindications for Oxytocin?
- Significant cephalopelvic disproportion.
- Unfavorable fetal positions.
- Fetal Distress.
- Hypertonic or Hyperactive uterus.
What conditions contraindicate a vaginal delivery?
- Active genital herpes.
- Prolapse of cord.
- Total placenta previa.
What class of medications are used in Postpartum Hemorrhage? Name the med?
- Ergot Derivatives.
2. Methylergonovine (Methergine).
MOA: affects primarily uterine smooth muscle producing sustained contractions and thereby shortens the 3rd stage of labor?
Methylergonovine (Methergine) – Ergot Derivative.
Indications for Methylergonovine (Methergine)?
- Prevention and treatment of postpartum and post-abortion hemorrhage caused by uterine atony or subinvolution.
What is Uterine Atony?
When the uterus fails to contract after the delivery of the baby, which can lead to a potentially life-threatening condition known as postpartum hemorrhage.
What is Subinvolution?
When the uterus does not return to normal size after delivery.
Adverse effects of Methylergonovine (Methergine)?
- CV – MI, HTN, Palpitations.
- Ergotism.
- Metabolic/GI – N/V/D, Water intoxication.
What is the condition of early symptoms of poisoning include nausea, vomiting, muscle pain and weakness, numbness, itching, and rapid or slow heartbeat; it can progress to gangrene, vision problems, confusion, spasms, convulsions, unconsciousness, and death?
Ergotism.
What do we monitor with the use of Methylergonovine (Methergine)?
BP, HR, Uterine Response.
Drug interactions with Methylergonovine (Methergine)?
CYP450, Azoles, many Abx, Serotonin agonists.
What narcotics can we use as analgesia in labor?
Meperidine (Demerol), Morphine, Fentanyl – IV or IM.
What medications can be used as augmentation of pain relief?
Antihistamines – Promethazine or Hydroxyzine.
What are some concerns with Epidural Analgesics?
- Greater risk of need for Oxytocin.
- Longer stages of labor.
- Greater risk of intervention.
What is the 1st line medication for HTN in pregnancy? Alternatives?
**1st line: Methyldopa.
Alternatives: Nifedipine (CCB) or BBs.
What is the risk of using Beta Blockers for HTN in pregnancy?
Possibly associated with reduced growth of fetus, but could be due to underlying maternal medical condition.
Hypertension + Proteinuria after the 20th week of pregnancy?
Pre-Eclampsia/Eclampsia.
*Proteinuria results from hepatic or renal dysfunction.
Signs and Symptoms of Pre-Eclampsia/Eclampsia?
- Headache.
- Edema of hands and face.
- Weight gain >2 lbs/wk or sudden weight gain over 1-2 days.
What is the cure for Pre-Eclampsia/Eclampsia?
ONLY cure/Tx is Delivery.
What are the indications for delivery in pre-eclampsia/eclampsia?
- Fetal: severe IUGR, fetal compromise, oligohydramnios (amniotic fluid < expected).
- Maternal: > 37 wks, low platelets, worsening hepatic and renal function, eclampsia.
What does IUGR stand for?
Intrauterine Growth Restriction (Fetal growth restriction).
What is Eclampsia?
The severe form of pre-eclampsia characterized by HTN in pregnancy that leads to seizures.
What is the medical management of Pre-eclampsia/Eclampsia?
- Bed rest and minimal activity.
- Seizure Prophylaxis – mag sulfate.
- Control of BP – Hydralazine or Labetalol.
Infection of the uterus most common after cesarean delivery?
Metritis.
What is the cause of Metritis and what do we treat with?
- Polymicrobial with anaerobic organisms.
- Tx with Broad-Spectrum Abx:
- -Cefotetan, Cefoxitin.
- -Ampicillin + Aminoglycoside (Gentamicin, Streptomycin).
- -Clindamycin + Gentamicin.
**Provide additional Abx coverage if no response in 48-72 hrs.
Define Mastitis?
Breast infection most commonly occurs in lactating women several weeks after delivery.
Clinical presentation of significant fever, chills, malaise and vague breast symptoms?
Mastitis.
What is the cause of Mastitis and what do we treat with it?
- MCC is Staph Aureus.
2. Treat with Dicloxacillin.
