Autocoids Flashcards

1
Q

What are autocoids?
List the three types of autocoids

A

Self-healing substances.
Amine autocoids (histamine, serotonin)
Lipid derived autocoids (prostaglandin, leukotriene, platelet activating factor)
Peptide autocoids (bradykinin, angiotensin)

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2
Q

What is eicosanoids?
Examples?

A

They are from the lipid derived autocoids, aka eicosanoids= essential fatty acid
Examples : thromboxane, prostaglandins, leukotriene

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3
Q

What are COX 1 & COX 2?

A

They are enzymes which play a key role in the synthesis of eicosanoids, specifically prostaglandins and thromboxanes.

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4
Q

Difference between COX 1 & COX 2

A

COX 1 :produce TXA2 which is procoagulatory, prostaglandin to protect stomach from acids
Mostly expressed in tissues
Non-selective COX inhibitor/NSAIDs such as aspirin , ibuprofen

COX 2
Inductively
Present at sites of inflammation and cancer
COX 2 inhibitor such as celecoxib

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5
Q

The four types of histamine receptors are?

A

Histamine is stored in mast cell.
The four types:
H1- smooth muscles, blood vessel
H2- gastric glands, blood vessels, heart
H3- brain
H4- eosinophils, neutrophils, CD4 T cells/Th

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6
Q

The pharmacological actions of histamine

A

relate histamine to ALLERGY

exocrine secretion: increased production of nasal & bronchial mucus
bronchial smooth muscle: bronchoconstriction
intestinal smooth muscle: constriction
sensory nerve endings: itching & pain
cardiovascular system: reduce peripheral resistance, decrease in BP, positive chronotropic & inotropic effect
skin: triple response ( RED SPOT, FLUSH, WHEAL)
stomach: increase gastric acid secretion

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7
Q

Classification of antihistamine drugs is divided into

A

1st gen : chlorpheniramine / chlorphenamine
2nd gen: cetirizine

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8
Q

How 2nd gen histamine blockers/ antihistamine differs from 1st gen?

A

NON SEDATIVE
DON’T CAUSE ANTICHOLINERGIC ADVERSE EFFECTS like dry mouth
High H1 selectivity
Do not impair psychomotor performance
No increase in appetite/ no weight gain

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9
Q

Mechanism of action of antihistamine

A
  1. Block action of histamine at receptor site
  2. Compete with histamine for binding at receptor
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10
Q

Pharmacokinetic features of antihistamine

A

Given orally
Metabolise in liver, excrete through urine
1st gen H1 antagonist can cross BBB

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11
Q

Adverse effects of antihistamine

A

She Did Do The Freaking Bad Calculation Really
Sedation
Dry mouth
Dizziness
Tinnitus
Fatigue
Blurred vision
Constipation
Retention of urine

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12
Q

Example of histamine release inhibitor

A

disodium cromoglycate
-prevent mast cell degranulation

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13
Q

Uses of antihistaminic drugs

A

Allergic reactions
Motion sickness
Vertigo

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14
Q

What is serotonin/ 5HT?

A

A neurotransmitter in CNS.
Can be found in :
GIT enterochromaffin cells
Platelets
Lungs
Bone marrow
Pineal gland

It had 7 receptors & all are GPCR except 5HT 3 which is LIGAND-GATED

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15
Q

The pharmacological effects of serotonin?

A

Nervous system: vomiting, pain, regulate mood sleep behavior temperature
Respiratory system: bronchoconstriction
CVS: vasoconstriction, increase HR and force of contraction, platelet aggregation
GIT: + gastric peristalsis & secretion

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16
Q

List the uses of serotonin agonist & antagonist

A

Agonists:
buspirone: anxiety
sumatriptan: migraine
cisapride: gastroesophageal reflux disease (GERD)

Antagonists:
ondansetron: vomiting
clozapine: psychosis

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17
Q

Adverse effects of serotonin agonists & antagonists

A

Agonists: nausea, vomiting, palpitation, flushing
Antagonists: constipation, drowsiness, arrhythmia

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18
Q

Buspirone is used for

A

Anxiety

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19
Q

Sumatriptan is used to treat

A

Migraine

20
Q

Cisapride is used to treat

A

GERD

21
Q

Ondansetron is used to treat

A

Vomiting

22
Q

Clozapine is used to treat

A

Psychosis

23
Q

Uses of prostaglandins

A

O&G:
induce labour (dinoprostone)
Terminate pregnancy
Post partum haemorrhage

GIT disorders: prevention of NSAIDs induced ulcers/ peptic ulcers (misoprostol)

Ophthalmic disorders: glaucoma (latanoprost)

24
Q

List all the prostaglandins & thromboxane

A

PGE2
PGD2
PGF2a
PGI2/prostacyclin
TXA2

25
Q

Action of PGE2

A

Inhibits gastric acid secretion (treat peptic ulcer)
Increase gastric mucus production (treat peptic ulcer)
Lower intraocular P (glaucoma: high IOP)
Bronchodilation

26
Q

Actions of PGD2

A

Bronchoconstriction
Inhibits platelet aggregation (treat myocardial infarction)

27
Q

Actions of PGF2a

A

Bronchoconstriction
Myometrial contraction (abortion)

Lower IOP

28
Q

Actions of PGI2 / prostacyclin

A

Bronchodilatation
Inhibits platelet aggregation (MI)

29
Q

Actions of TXA2

A

Vasoconstriction
Stimulates platelet aggregation (MI)

30
Q

Two main categories of leukotrienes

A

Leukotrienes are released by WBC
chemoattractant LTB 4 & cysteinyl LTC 4, D4, E4, F4

31
Q

Function of LTB 4/ chemoattractant & cysteinyl

A

LTB 4 is for all types of inflammation
Cysteinyl is for asthma & allergic rhinitis

Leukotriene receptors are all GPCRs

32
Q

Pharmacological actions of leukotrienes

A

Resp: bronchoconstriction, increase mucus secretion
CVS: fall in BP, constriction of small coronary resistance vessels [IV] ; increase nasal blood flow & local vascular permeability [topically in nose]; wheal & flare [subcut]

33
Q

Uses of leukotrienes antagonists

A

Montelukast, Zafirlukast : asthma, allergic rhinitis, allergic conjunctivitis
Zileuton: bronchial asthma

**montelukast blocks leukotrienes receptors
**zileuton inhibits synthesis of leukotrienes
However, it all boils down to treat bronchial asthma, just different MOA

34
Q

List the autocoid involved and think of suitable agents for the conditions.
1. anaphylactic shock
2. Severe gastritis/peptic ulcers
3. Motion sickness
4. Severe nausea & vomiting
5. Difficulty in giving birth
6. Migraine

A
  1. Histamine-adrenaline
  2. PGE1-misoprostol
  3. Histamine-hydroxyzine
  4. serotonin 5HT3-ondansetron
  5. PGE2-dinoprostone (to induce labour)
  6. serotonin 5-HT1B/D- sumatriptan
35
Q

To relieve?
Motion sickness

A

Hydroxyzine

36
Q

To relieve?
Allergy

A

Cetirizine

37
Q

To relieve?
Anxiety

A

Buspirone

38
Q

To relieve?
Migraine

A

Sumatriptan

39
Q

To relieve?
Gastroesophageal reflux disease (GERD)

A

Cisapride

40
Q

To relieve?
Nausea & vomiting

A

Ondansetron

41
Q

To relieve?
Psychosis

A

Clozapine

42
Q

To induce labour?

A

Dinoprostone

43
Q

To relieve?
Peptic ulcers

A

Misoprostol (PGE1)

44
Q

To relieve?
Glaucoma

A

Latanoprost

45
Q

To relieve?
Asthma, allergic rhinitis, allergic conjunctivitis

A

Montelukast
Zafirlukast

46
Q

To relieve?
Bronchial asthma

A

Zileuton