Pharmacotherapy Flashcards

Flashcards covering action, dosage, side effects, and nursing implications for Magnesium Sulfate, Nifedipine, Indomethacin, and Betamethasone based on pharmacotherapy lecture notes.

What is the primary action and gestational indication for Magnesium Sulfate in obstetric care?

It relaxes uterine muscles to stop irritability and contractions (off-label use), is used in seizure prophylaxis & treatment of pre-eclamptic and eclamptic patients, and acts as a neuroprotective agent for newborns at 24-32 weeks gestation.

What are the loading dose, maintenance dose, and route of administration for Magnesium Sulfate?

Loading dose: 4 – 6 grams over 30 min. Maintenance dose: 2-3 grams/hr. Route: IV.

Why is continuous IV administration of Magnesium Sulfate limited to 5-7 days?

It may cause low Ca+ and alter fetal bone structure.

What are the signs of Magnesium toxicity, and what antidote should be available?

Signs include ALOC, depressed respirations and DTR's, slurred speech, weakness, and resp &/or cardiac arrest. Calcium gluconate must be kept on hand.

What are the key nursing monitoring requirements and fluid restrictions for a patient receiving Magnesium Sulfate?

Monitor vital signs (especially respirations) and assess deep tendon reflexes (DTR) hourly (hold if DTR absent); monitor LOC and urine intake/output hourly; restrict fluids to 100 cc/hr (2400 cc/day); check serum Magnesium levels q 4-6 hours as ordered.

In which patients is Magnesium Sulfate contraindicated?

Contraindicated in patients with a history of MI, heart block, or coma.

What is the action and optimal gestational age range for Nifedipine (Procardia)?

It blocks calcium movement into smooth muscle cells and inhibits uterine activity to arrest preterm labor (tocolytic). It is best for 32-34 wk gestation.

What is the dosing regimen for Nifedipine (Procardia)?

Initial dose of 30 mg PO, followed by 10-20 mg q 4-6 hours.

What side effects are associated with Nifedipine (Procardia)?

Occasional facial flushing, mild H/A, transient tachycardia, palpitations, decreased BP, and a rise in serum liver enzymes.

What nursing implications and contraindications apply to Nifedipine (Procardia)?

Monitor BP for hypotension (especially hourly if given with MgSO4 and report HR > 110bpm), monitor for orthostatic hypotension, assess fetal surveillance for bradycardia or transient fetal tachycardia. It is contraindicated in patients with cardiovascular disease or hemodynamic instability.

What is the mechanism of action and dosing regimen for Indomethacin (Indocin)?

Action: Inhibits prostaglandins (which stimulate contractions) and inhibits uterine activity to arrest preterm labor. Dose: Initially 100mg rectally; followed by 25-50 mg q 4-6 hours PO.

What are the maximum duration of use and gestational age limit for Indomethacin (Indocin)?

No use beyond 48 hours, and it is contraindicated after 32 wk. gestation.

What fetal complications are associated with Indomethacin (Indocin) use?

Oligohydramnios, constriction of ductus arteriosus or premature closure of ductus, and pulmonary hypertension.

What maternal conditions contraindicate the use of Indomethacin (Indocin)?

History of peptic ulcer disease, history of asthma, fetal growth restriction, or allergy to ASA or NSAIDS.

What is the primary action and target population for Betamethasone (Celestone)?

Promotes fetal lung maturity by stimulating surfactant production; prevents or reduces the risk of respiratory distress syndrome and intraventricular hemorrhage in preterm neonates < 34 weeks gestation.

What is the prescribed dose and administration route for Betamethasone (Celestone)?

Administer two (2) doses IM 24 hours apart.

What side effect and key nursing implications are associated with Betamethasone (Celestone)?

Side effect: Shortness of breath. Nursing implications: Monitor for maternal infection, educate parents about potential benefits on preterm infants, and assess maternal lung sounds for potential pulmonary edema.