Autacoids Flashcards
Rlease of other autocoids
PAF, metabolites of arachidonic acid, leukotriene D4, kinins
Histamine
From histidine via decarboxylation
L-histidine decarboxylase
Requires antigen and igE
Causes hypersensitivity and allergic response
H2
Gastric mucosa, cardiac muscle, mast cells, brain
Inc gastric acid secretion, inc pepsin, inc intrinsic factor
Triple response of lewis
Localized red spot- direct vasodilating effect
Flare- stim of axon reflexes
Wheal- inc capillary
Non sedating H1 blockers
Loratadine, fexofenadine
2nd generation
H1 blockers For motion sickness
Meclizine
Adverse effects 1st gen
Depression, sedation, fatigue, tinnitus, emesis, dry mouth,
Teratogenic: melanoma fibrosa, in breast milk, irritability, drowsiness
AE 2nd gen
Polymorphic ventricular tachycardia, prolonged QT interval
Leukopenia, agranulocytosis
H2 antag
U: gastric, ulcers, gerr
AE: confusion, dizziness
CIMETIDINE: inhibits microsomal enzymes, impotence, gynecomastia, galactorrhea
Serotonin
Rate limiting is tryptophan hydroxylase
Sibutramine- inhibits 5HT reuptake regulating food intake
Stimulates ACTH, GROWTH HORMONE, PROLACTIN
Inhibits: LH FSH TSH
Keymediator in migraine
Triptans
For migraines!
D: Sumatriptan, naratriptan, rizatriptan, zolmitriptan
AE: bitter taste, paresthesia, asthenia, fatigue, flushing
C/I: CV AND HPN!! ; naratriptan: with renal or hepatic impairment
Drugs that affect serotonin levels
Tryptophan
Inhibitors of membrane reuptake- imipramine, fluoxetine
Inhibitors of degradation- MAO
Inhibitors of neuron vesicle uptake- reserpine, tetrabenezine
Cyproheptadine- block h1 and serotonin
SSRI- antidepress
Ergot alkaloids
Egotamine
METHYSERGIDE- 5HT RECEPTOR ANTAGONIST
Bomocriptine
U: for HYPERPROLACTINEMIA: given bromocriptine
Enzymes acting upon arachidonic acid
5-LIPOXYGENASE
CYCLOOXYGENASE
PGD2
FLUSHING, NASAL STUFFINESS, DEC BP
F RING METABOLITES INC BP
Kidney and urine formation in lipid derived autacoids
EXAM
PGEs- inhibit water reabsorption by vasopressin
PGE2 and PGI2- inc renal blood flow, inc gfr, through vasod
TxA2- dec renal blood flow, dec gfr
LOX metabolites
Stimulates release of aldosterone
Properties of leukocytes
EXAM
Systemic administration- leukocytopenia
In stomach, PAF
EXAM
most potent known ulcerogen
