Kg - Pharm 2 Exam 3, Uterine Drugs Flashcards
types of drugs used for uterine contraction?
- estrogens
- prostaglandins
- oxytocin
- stretching
types of drugs used for uterine relaxation?
- beta adrenergic drugs (b2 relax all smooth muscle)
- progesterone
- alcohol
- MgSO4
DOC for inducing labor at term? (and why?)
oxytocin
- NUMBER AND SENSITIVITY OF OXYTOCIN RECEPTORS in uterus increase just prior to delivery
what is useful to induce abortions during second trimester? (and why?)
prostaglandins
- uterus gen resistant to stimulation during 2nd trimester, but prostaglandins can CAUSE STRONG LABOR LIKE CONTRACTIONS at this stage
in postpartum hemorrhage, why is uterine massage 1st line treatment?
physical stretching stimulates uterine muscle contractions
how/when is oxytocin usu released?
in response to suckling/cervical pressure
oxytocin - indications/therapeutic effects?
DOC to INDUCE LABOR AT TERM IF INDICATED
- causes timed contractions
- IV infusion preferred
- augment labor in pts w/ uterine dysfunctional inertia
FOR PREVENTION OF HEMORRHAGE
- IM route preferred
STIMULATION OF MILK LET DOWN REFLEX
- nasal application method preferred
oxytocin - adverse effects
- WATER INTOXICATION w/ convulsions
- -> bc of ADH like effect (only if doses large/prolonged infusion)
- UTERINE RUPTURE w/ large dose
- allergy
- ANAPHYLAXIS
- SINUS BRADYCARDIA of fetus
oxytocin - pharmacokinetics?
- very short half life 1-6 min
- inactivated by liver/kidneys
oxytocin - contraindications/precautions?
anything that prevents vaginal delivery
- malpresentation
- cephalopelvic disproportion
- placenta previa
- uterine scar
- unengaged head
- cervical scarring
Ergot alkaloids - MOA
- contraction of uterine smooth muscle via activation of serotonin and alpha adrenergic receptors
ergot alkaloids - indications/therapeutic effects
- AFTER COMPLETION OF LABOR/DELIVERY OF PLACENTA to produce firm uterine contraction to decrease uterine bleeding
–> 2nd line after massage and oxytocin have failed
(for same reasons following suction abortion)
ergot alkaloids - pharmacokinetics
- rapid action (30-40 sec after IV, 10 min after oral use)
- lasts several hours
ergot alkaloids - adverse effects
- transient hypertension (contracts all smooth muscle)
- angina, MI
ergot alkaloids - contraindications/precautions?
- NEVER USED TO INDUCE LABOR (would cause fetal hypoxia)
- OBLITERATIVE VASCULAR/CAD
dinoprostone - indications/therapeutic effects
- expulsion of uterine contents (intrauterine fetal death, miscarriage, elective abortion)
- cervical ripening prior to delivery at term
dinoprostone - pharmacokinetics
abortion:
- one suppository in vagina (subsequent q 3-5 hrs until abortion occurs)
for cervical ripening:
- apply gel to cervix
dinoprostone - adverse effects
- GI, VOMITING, DIARRHEA***
- fever, chills, HA
dinoprostone - contraindications/precautions
abortion - NOT TO BE USED w/:
- acute pelvic inflammation
- ACUTE CARDIAC, PULMONARY, RENAL, HEPATIC DZ
- ASTHMA, HTN, ANEMIA, JAUNDICE, EPILEPSY
for cervical ripening:
- fetal distress
- hx difficult deliveries or c-section
carboprost tromethamine - indications/therapeutic effects?
- induce abortion in 13th/20th wk
- postpartum bleeding due to uterine atony
- -> 3rd like after massage, oxytocin, ergots
dinoprostone - info?
synthetic prostaglandin E2
carboprost tromethamine - info?
derivative of PGF2
carboprost tromethamine - pharmacokinetics?
- IM
- methylation increases half life from 15 sec to 8 min
carboprost tromethamine - adverse effects?
- not serious if used properly
- systemic PG actions often diagnosed as anaphylactic shock
- VOMITING, DIARRHEA
- fever, rash
carboprost tromethamine - contraindications/precautions?
NOT TO BE USED IN PTS w/:
- acute pelvic inflammation
- ACUTE CARDIAC, PULMONARY, RENAL, HEPATIC DZ
- ASTHMA, HTN, ANEMIA, JAUNDICE, EPILEPSY
goal of uterine relaxants?
prevent premature labor/delay premature delivery until term/until fetus has matured to 37th week
- IF NEEDED, delivery can be before 37th week if fetal lungs developed (corticosteroids!)
- NO OPTION IS FDA APPROVED or DOC
MgSO4 - MOA
mechanism unknown
- probably relaxes uterus by direct effect
MgSO4 - indications/therapeutic effect?
- considered 1st like drug
- can prevent convulsions in pre-eclampsia and treat eclampsia (FDA app)
MgSO4 - pharmacokinetics?
- IV, slowly
MgSO4 - adverse effects?
- flushing, diaphoresis,hypotension
- depressed DTRs, muscle paralysis, weakness, lethargy, hypothermia
- circulatory collapse, cardiac/respiratory depression
nifedipine - info?
CCB
nifedipine - MOA?
inhibits Ca2+ influx (muscle contraction)
nifedipine - indications/therapeutic effects?
becoming 1st line agent for uterine relaxation
indomethacin - info?
first 2nd line drug to delay labor
indomethacin - MOA?
- strong inhibitor COX enzyme
- reduction prostaglandin synthesis
indomethacin - adverse effects?
- maternal GI irritation, peptic ulceration, thrombocytopenia, allergic rxn, HA, dizziness
- reports abt PARTIAL CLOSURE OF FETAL DUCTUS ARTERIOSUS, impaired renal function, bronchopulmonary dysplasia, persistent HTN in neonatal period
progesterone - indications/therapeutic effects?
- more effective than placebo in maintaining length of pregnancy when given PROPHYLACTICALLY from 16th to 37th week or until delivery
- -> NOT EFFECTIVE FOR ACUTE TREATMENT
- for high risk women/women w/ hx preterm births
nitroglycerine - info
EMERGENCY USE ONLY - in case of uterine rupture!
nitroglycerine - indications/therapeutic effects?
quick uterine relaxation, EMERGENCY ONLY
nitroglycerine - contraindications/precautions?
- uncorrected hypovolemia
- severe anemia
- increased intracranial pressure
- constrictive pericarditis/pericardial tamponade
- hypersensitivity
ethanol - info
historically used in rural areas
ethanol - MOA?
direct relaxant effect on myometrium and inhibition of oxytocin release
ethanol - indications/therapeutic effects?
inhibit premature labor
ethanol - pharmacokinetics?
- loading dose (10% injection) for 2 hrs w/ maintenance infusion rate for up to 10 hrs
oxytocic = ___?
uterine contractions
tocolytic = ___?
uterine relaxation
