Oral Anticoagulant Agents

The correct answer is 1, 3 and 4 — Rivaroxaban, Apixaban, and Dabigatran — as these are all Direct Oral Anticoagulants (DOACs) that can be taken by mouth, whereas Fondaparinux requires parenteral (subcutaneous) administration.

Analysis of Each Agent

• Rivaroxaban — An oral direct Factor Xa inhibitor, used for stroke prevention in atrial fibrillation, DVT/PE treatment and prophylaxis. Administered orally.
• Fondaparinux — A synthetic pentasaccharide that acts as an indirect Factor Xa inhibitor (via antithrombin). It has poor oral bioavailability and is only given by subcutaneous injection, not orally.
• Apixaban — Another oral direct Factor Xa inhibitor, similar in class and use to rivaroxaban. Administered orally.
• Dabigatran — A direct thrombin (Factor IIa) inhibitor available as an oral prodrug (dabigatran etexilate). Administered orally.

Why the Other Options Are Incorrect

• 1 and 3 only — Incomplete; this omits Dabigatran, which is also an oral agent.
• 1, 2 and 4 — Incorrect because it includes Fondaparinux, which cannot be given orally (it is administered subcutaneously) and excludes Apixaban, which is oral.
• 2, 3 and 4 — Incorrect because it includes Fondaparinux, the only agent in the list that is not an oral drug.

Conclusion

Since Rivaroxaban, Apixaban, and Dabigatran are all direct oral anticoagulants, while Fondaparinux is administered only by injection, the correct combination is 1, 3 and 4.