All of the following are true regarding sumatriptan except: September 2009
## Core Concept
Sumatriptan is a selective serotonin receptor agonist, specifically targeting the 5-HT1B and 5-HT1D receptors. It is primarily used for the acute treatment of migraine attacks. The drug works by causing vasoconstriction of the intracranial blood vessels and inhibiting the release of pro-inflammatory neuropeptides.
## Why the Correct Answer is Right
The correct answer, which is not specified here, needs to be evaluated based on the properties and uses of sumatriptan. Generally, sumatriptan is known for its effectiveness in treating migraine headaches by selectively agonizing serotonin receptors, which leads to the constriction of blood vessels and a decrease in the release of inflammatory mediators.
## Why Each Wrong Option is Incorrect
Since the specific details of the options (A, B, C, D) are not provided, let's hypothetically analyze:
- **Option A:** If it states that sumatriptan is used for the prophylaxis of migraine, this would be incorrect because sumatriptan is used for the acute treatment of migraine attacks, not for prophylaxis.
- **Option B:** If it mentions that sumatriptan acts on 5-HT1B and 5-HT1D receptors, this would be correct and not the answer we're looking for.
- **Option C:** If it notes that sumatriptan can cause vasoconstriction, this would be correct as it works by causing vasoconstriction of intracranial blood vessels.
- **Option D:** If it states that sumatriptan can be administered orally, this could be partially correct but misleading because while sumatriptan can be given orally, it is also available in other forms like nasal spray and injection, and its oral bioavailability is limited due to first-pass metabolism.
## Clinical Pearl / High-Yield Fact
A key point to remember about sumatriptan is that it should not be used in patients with certain cardiovascular conditions due to its potential to cause vasoconstriction. Additionally, it is not recommended to be taken with or shortly after using other triptans or ergotamine-containing or ergot-type drugs due to the risk of prolonged vasoconstriction.
## Correct Answer: D. Oral bioavailability is 100 percent.
Given a likely incorrect statement about sumatriptan's oral bioavailability being 100 percent (which would actually be around 14% due to first-pass metabolism),
**Correct Answer: D.**