4.2 - Autocoids - Serotonin Flashcards
1
Q
Biosynthesis
A
- Precursor
- Locations
- Steps
- Receptors
- Drugs
2
Q
Precursor
A
L-Tryptophan
3
Q
Locations
A
• Enterochromaffin cells – GIT – > 90% of 5-HT • Platelets • CNS
4
Q
Steps
A
L-tryptophan ➡️1️⃣ 5-hydroxytryptophan ➡️2️⃣ 5-hydroxytryptamine
5
Q
1️⃣
A
Hydroxylation
6
Q
2️⃣
A
Decarboxylation
7
Q
Effects
A
- Central
* Peripheral
8
Q
Central
A
- Mood regulation
- BP regulation
- Thermoregulation
- Emesis
9
Q
Peripheral
A
- GIT
- Blood vessels
- Platelets
- Brochi
- Uterine SM
10
Q
GIT
A
Peristalsis
11
Q
Blodo vessels
A
Vasoconstriction
12
Q
Platelets
A
Platelet aggregation
13
Q
Bronchi
A
Bronchospasm
14
Q
Uterine SM
A
Contraction — Oxytosis
15
Q
Receptors
A
- 5-HT1a
- 5-HT1B/1D
- 5-HT2a/2B
- 5-HT3
- 5-HT4
16
Q
5-HT1a
— pre-synaptic (CNS)
A
INHIBITION of 5-HT release
17
Q
5-HT1B/1D
— Peripheral Blood vessels
A
Vasoconstriction
18
Q
5-HT2a/2B
— Smooth Muscles
A
Contraction
- Vasoconstriction
- Oxytocic effect
19
Q
5-HT3
— Area postrema of the brain (CTZ)
A
Emesis
20
Q
5-HT4
— GIT
A
⬆️ GI motility
21
Q
Drugs
A
- 5-HT1a
- 5-HT1B/1D
- 5-HT2a/2B
- 5-HT3
- 5-HT4
22
Q
5-HT1a
A
Partial Agonist
– Buspirone
- Anxiolytic
23
Q
5-HT1B/1D: AGONISTS
— -triptan
A
• Sumatriptan • Zolmitriptan • Naratriptan • Rizatriptan (Vasoconstriction)
24
Q
⬆️est BA
A
Naratriptan
25
Use: 5-HT1B/1D AGONISTS
Mgt of acute migraine HA
26
S/E: 5-HT1b/1D
⬆️ BP
27
C/I: 5-HT1b/1D
* HTN
| * CAD
28
5-HT2a/2B
* Antagonist
| * Agonists
29
5-HT2a/2B: AGONIST
```
Ergotamine
(Vasoconstriction)
– PO
– PR
– Nasal
– SQ
```
30
Use: 5-HT2a/2B Agonist
| — Ergotamine
• Mgt of acute migraine HA
- Ergotamine/ Ergonavine
• Mgt of post partum hemorrhage
- Ergonovine
31
```
‼️
– Claviceps purpurea
– Rye
– Vasoconstriction
– Ergot Toxicity (St. Anthony's Fire)
```
Ergot
32
S/E: Ergot derivatives
* ⬆️ BP
| * Oxytocic effect
33
5-HT2a/2B: ANTAGONIST
* Methysergide
* Ketansiren
– Vasodilation
34
– Use: Prophylaxis for migraine HA
| – S/E: Retroperitoneal fibrosis
Methysergide
35
– Europe
– Antihypertensive
– a1 antagonist
Ketansiren
36
5-HT3: ANTAGONISTS
— -setron
— anti-emetics
* Granisetron
* Ondnasetron
* Palonosetron
* Dolasetron
37
Transdermal patch
Granisetron
38
– T 1/2: 40 hrs
| – Single dose: 5 days
Palonosetron
39
Use: 5-HT3 ANTAGONISTS
Mgt of Chemotherapy-induced N & V
40
Route:
* IV
| * PO
41
– GIT
| – Mgt of irritable bowel syndrome with diarrhea
Alosetron
42
5-HT4
* Partial Agonists
| * Full Agonist
43
Partial Agonists
* Tegaserod
| * Cisapride
44
Use: PARTIAL AGONISTS
Mgt of irritable bowel syndrome with predominant constipation
45
Full Agonist:
| — Prucalopride
Mgt of chronic constipation
