Q- Which one of the following medications is contraindicated in pregnancy due to the risk of fetal tooth discoloration?
A- Amoxicillin
B- Cephalexin
C- Erythromycin
D- Tetracycline
D- Tetracycline- Tetracyclines cross the placenta and can cause permanent yellow-gray-brown discoloration of the fetus’s teeth. They also interfere with bone growth in the fetus.
Q- Which one of the following clinical trials primarily evaluates drug safety?
A- Phase I
B- Phase II
C- Phase III
D- Phase IV
A- Phase I- This phase primarily evaluates drug safety. It includes 100–300 patients with the disease. Phase II evaluates efficacy and continues to evaluate safety. Phase III confirms efficacy, monitors side effects, compares with existing treatments. Phase IV is the post-marketing surveillance to detect long-term adverse and rare side effects after the drug is approved.
Q- A patient on warfarin therapy should avoid which one of the following vitamins?
A- Vitamin B12
B- Vitamin C
C- Vitamin D
D- Vitamin K
D- Vitamin K- Warfarin inhibits the vitamin K epoxide reductase enzyme, reducing activation of clotting factors II, VII, IX, and X. Excessive intake of vitamin K (from diet or supplements) provides more substrate for clotting factor synthesis, which can reduce warfarin’s anticoagulant effect. This increases the risk of thromboembolic events (like stroke or DVT).
2 thoughts on “Repeated USMLE Questions Step 1- Review- 117”
Matiwos, I don’t have a book of pharmacology yet but you can follow this link and you can review all of my questions online: https://qbankusmle.com/tag/pharmacology/
Matiwos, I don’t have a book of pharmacology yet but you can follow this link and you can review all of my questions online: https://qbankusmle.com/tag/pharmacology/
How can ibget the book of pharmacology please?