22-year-old Megha comes to the doctor because of a missed menstrual period. She has hypothyroidism for which she takes thyroxine; she has an artificial heart valve, for which she takes Coumadin, and she recently started tetracycline for acne. Urine human chorionic gonadotropin (hCG) is positive. Which of the following medication should the patient continue to take during pregnancy?

1. A

   Thyroxine

2. B

   Coumadin

3. C

   Tetracycline

4. D

   Oral contraceptive pill (OCP)

Appeared in: AIIMS Nagpur NO- 2020

Explanation

• Thyroxine (levothyroxine) is essential for managing maternal hypothyroidism.
• Untreated or inadequately treated hypothyroidism during pregnancy can lead to severe adverse outcomes for both the mother and the fetus, including miscarriage, pre-eclampsia, and impaired fetal brain development.
• The fetal brain depends on maternal thyroxine, especially during the first trimester.
• Pregnancy increases the requirement for thyroxine, so the dose often needs to be increased and monitored closely to maintain normal TSH levels.

Why Other Options Were Wrong

• Option B: Coumadin (warfarin) is a known teratogen (Pregnancy Category X). It crosses the placenta and can cause fetal warfarin syndrome, which includes nasal hypoplasia, skeletal abnormalities, and central nervous system defects.
• Option C: Tetracycline is contraindicated in pregnancy (Pregnancy Category D). It can cause permanent discoloration (yellow-brown staining) of the fetus's deciduous teeth and may inhibit skeletal bone growth.
• Option D: Oral contraceptive pills (OCPs) are used to prevent pregnancy. Since the patient is already pregnant, there is no medical reason to continue them. They are contraindicated in pregnancy.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Medication safety during pregnancy to guide bedside assessment, documentation, and the next nursing action.
• A crucial nursing responsibility is medication reconciliation and patient education, especially at the first antenatal visit. Nurses must identify potentially harmful medications and facilitate communication with the provider to ensure a safe treatment plan.
• Nurses play a key role in monitoring for adverse effects and therapeutic effectiveness of medications continued during pregnancy, such as monitoring TSH levels for a patient on thyroxine.
• What if? If the patient's TSH level was found to be elevated despite taking her usual dose of thyroxine, it would indicate that her hypothyroidism is not adequately controlled for pregnancy. The nurse should anticipate an order from the provider to increase the thyroxine dose and schedule follow-up blood tests.

How to Approach the Question

• First, identify the core of the question: which of the patient's current medications is safe and necessary to continue during her confirmed pregnancy.
• Analyze each medication listed in the patient's history: Thyroxine, Coumadin, and Tetracycline.
• Evaluate each option based on its known effects during pregnancy. Recall or determine the pregnancy risk category for each drug.
• Thyroxine (Category A): Essential for a pre-existing condition (hypothyroidism) that affects both mother and fetus. It must be continued.
• Coumadin (Category X): A known teratogen. It must be stopped and replaced.
• Tetracycline (Category D): Known to cause harm to the fetus. It must be stopped.

Concept Tested & Keywords

• Concept Tested: Medication safety during pregnancy
• Stem keywords: pregnancy, hypothyroidism, thyroxine, artificial heart valve, Coumadin, tetracycline
• Lead-in keywords: continue to take
• Clinical cues: Patient is pregnant (positive hCG)
• Clinical cues: History of hypothyroidism and artificial heart valve requires chronic medication

Question ID

QFuatz8cZMdSVo3ETEGpNt

Copy ID

Reference Book

E6 Medicine Davidson Principles Practice 24e p. 1299-1301

E6 Pharmacology Katzung 16e p. 1086-1088