Question

Lasmiditan is an agonist at which serotonin receptor subtype?

• A. 5-HT_1A
• B. 5-HT_1D/1B
• C. 5-HT_1F
• D. 5-HT_2A/2c

Hint:

Serotonin (5-HT) receptors have many subtypes, and different anti-migraine drugs target different ones. Knowing the exact subtype helps explain a drug's selectivity and side-effect profile.

Answer 1

The Correct Option is C

Step 1: What is Lasmiditan?
Lasmiditan is a relatively new drug used for acute treatment of migraine. It is called a ditans (as opposed to triptans).

Step 2: Understanding serotonin receptor subtypes in migraine.
Triptans (like sumatriptan) are 5-HT_1B/1D agonists. They work by causing vasoconstriction of cranial blood vessels, which also limits their use in patients with cardiovascular disease.

Step 3: Why 5-HT_1F and not 1B/1D?
The 5-HT_1F receptor is found on trigeminal neurons. Its activation inhibits the release of neuropeptides (like CGRP) involved in migraine pain, without causing vasoconstriction. This is why Lasmiditan is safe for patients with heart disease.

Step 4: Evaluate Option 3 - 5-HT_1F.
Lasmiditan is a highly selective agonist at the 5-HT_1F receptor. This is specifically its mechanism. This is the correct answer.

Step 5: Eliminate other options.
Option 1 (5-HT_1A) receptors are targeted by buspirone (anxiolytic). Option 2 (5-HT_1D/1B) is the target of triptans, not lasmiditan. Option 4 (5-HT_2A/2C) is targeted by drugs like cyproheptadine for migraine prevention, not treatment.

Step 6: Conclusion.
Lasmiditan is a selective 5-HT_1F agonist used for acute migraine.
Answer: Option (3) — 5-HT 1F