H/5-HT

Histamine

What process

• Mast cells

• Basophils

Histamine is stored and found in the highest amounts in —

• Energy- and Ca2+-dependent degranulation/immunologic/allergic reaction

• Energy- and Ca2+-dependent degranulation/chemical/mechanical reaction

Two processes by which HISTAMINE IS RELEASED

Energy- and Ca2+-dependent degranulation reaction

Energy- and Ca

2+ - independent release (displacement)

Recall

Recall histamine receptors

• R-alpha methylhistamine

• Betazole (Histalog)

• Impromidine

Histamine agonists identify

• H3 specific

• tenfold greater activity at H2-receptors than at H1-receptors

• investigational agent; its ratio of H2:H1 activity is about 10,000

• Pyrilamine

• Tripelennamine

Ethylaminediamines

• Clemastine

• Dimenhydrinate

• Doxylamine

• Diphenhydramine

• Carbonoxamine

Ethanolamines

• Hydroxyzine

• Meclizine

• Cyclizinw

Piperazines

• Brompheniramine

• Chlorpheniramine

Alkylamines

Promethazine

Phenothiazine

Cyproheptadine

Methylpiperidine

Terfenadine (Seldane) → Fexofenadine

Piperidine

• 30 mins

• 3-6 hours

• 3-24 hours

• Sedation

• GI upset, nandv, constipation

• Anticholinergic effects

Adverse effects of histamine blockers

• Cimetidine (Tagamet) - prototype

• Ranitidine (Zantec) - most prescribed

• Famotidine (Pepsid AC) - most potent

• Nizatidine (Axid) - most bioavailable

Enumerate H2 antagonists

gastric parietal cell

competitive antagonists at the H2-receptor, which predominates in the gastric parietal cell.

cimetidine

CYP1A2, CYP2C9, CYP2D6, and CYP3A4

Cimetidine is a potent enzyme inhibitor. It ointerferes with several important hepatic cytochrome

P450 drug metabolism pathways, including those catalyzed by

• Cromolyn (Ital)

• Nedocromil sodium (Tilade)

Enumerate histamine release inhibitors/mast cell stabilizers:

Recall

Recall effects of 5-HT

• Tryptophan hydroxylase

• 5-HTP Decarboxylase

Identify enzymes in 5 HT Synthesis

• Enterochromaffin cells (GIT)

• Platelets

5-HT STorage

• 90% of Serotonin are found in:

• 10% in:

• MAO

• Aldehyde dehydrogenase

Identify enzymes on sertooni metabolism

• Neurons, astroglia (CNS)

• Liver, placenta, GIT

• Platelets

• 5-HT, Tyramine, Epi, NE

• Dopamine

Answer the ff:

• Both MAO ar elocated in:

• MAO-A outside locations:

• MOA-B outside locations:

• MOA-A Metabolizes:

• MAO-B Metabolizes:

Moclobemide

Selective MAO-A Inhibitor with a lesser risk for HTN Crisis

• Phenelzine, Tranylcypromine, Isocarboxazid

• Moclobemide

• Selegiline, Rasagiline

Enumerate the ff:

• Non selective MAOIs

• MAO-A inhibitors:

• MAO-B inhibitors:

Recall

Recall serotonin receptors

• Busprone (Buspar)

• Triptans

• Trazodone (Desyrel)

• Cisapride (Propulsid)

• Tegaserod

What are the serotonin agonists

• Fluoxetine (Prozac)

• Desfenfluramine (Redux)

• Sibutramine (Reductil)

What are the other serotonergic drugs

• Cyproheptadine (Periactin)

• Ondansetron

• Granisetron (Kytril)

• Ketanserin (Sufrexal)

• Clozapine (Clozaril)

• Risperidone (Risperdal)

What are the serotonergic antagonists

Eicosanoids

• Dinoprostone

• Carboprost tromethamine

• Mifeprostone

• Misoprostol

What are the prostaglandin abortifacients

• ED, PDA

• PGE1

Alprostadil:

• Uses

• What analog

PGE, PGI2

What cox analog is used for PVD

Misoprostol

Cox analog used for ulcers

• Latanoprost (stable long acting)

• Bimatoprost, Travoprost, Unoprostone

What PGF2A Analogs are used for glaucoma

NSAIDs

What are the prostaglandin

trigger contractions in the smooth muscles lining the bronchioles

Leukotriene effect on LTD4 receptor

• Montelukast, Zafirlukast

• Zileuton

Enumerate:

• 5-lox inhibitor

• LT Antagonist