Exam II - Autocoids

Autocoids

endogenous compounds that function as local hormones. Differ from circulating hormones because they are produced by many tissues rather than in specific endocrine glands.

prostaglandins

histamine

serotonin

name three examples of autocoids

histamine

autocoid stored in mast cells and basophils

mast cells and basophils

two cell types that store histamine

Amine oxidase

enzyme that rapidly inactivates histamine if it is not stored within granules found in mast cells and basophils.

increases respiratory mucus production and bronchoconstriction

what are two effects of H1 receptor stimulation on the respiratory tract?

smooth muscle constriction

what is the effect of H1 stimulation on the intestinal tract?

itching and pain

two effects of H1 stimulation at sensory nerve endings

positive inotropism (increase contractility)

effect of H1 stimulation on the heart

dilation and increased permeability

two effects of H1 stimulation on capillaries

positive inotropism (increased contractility) and positive chronotropism (increased heart rate)

two effects of H2 stimulation on the heart

dilation and increased permeability

two effects of H2 stimulation on capillaries

increased gastric acid secretion

effect of H2 stimulation on the GI tract

First generation antihistamines

antihistamines that are still widely used because they are effective and inexpensive but penetrate the central nervous system and cause sedation. They additionally cause other unwanted side effects because they interact with many other receptors as well.

chlorpheniramine, bropheniramine, promethazine

name three first generation antihistamines

allergy/inflammation

motion sickness/nausea

insomnia

three therapeutic applications of first generation antihistamines

motion sickness

therapeutic application of first generation antihistamines due to their ability to block central H1 and M1 muscarinic receptors.

Second generation antihistamines

antihistamines that are specific for peripheral H1 receptors. They are made polar by adding carboxyl groups, and therefore do not penetrate the central nervous system and do not cause sedation

cetirizine, fexofenadine, loratadine

name three second generation antihistamines

selectively block PERIPHERAL H1 receptors

why don't second generation antihistamines cause sedation like first generation?

Cholinergic, adrenergic, serotonin

three receptors in addition to H1 receptors that are blocked by antihistamines.

Dry mouth, urinary retention, sinus tachycardia

o three effects caused by the blocking of cholinergic receptors by antihistamines

Hypotension, dizziness, reflex tachycardia

three effects caused by the blocking of alpha-adrenergic receptors by antihistamines

Increased appetite

effect caused by the blocking of serotonin receptors by antihistamines

ketotifen, olopatadine, azelastine

name three ophthalmic antihistamines used in the treatment of allergic conjunctivitis

Epinephrine

this drug relieves systemic anaphylaxis by acting on beta 2 receptors found on smooth muscle. This caused cAMP mediated relaxation, counteracting bronchoconstriction caused by massive histamine release.

Monoamine oxidase inhibitors (MAOIs)

should not be administered with H1 antihistamines because they can exacerbate their sedative and anticholinergic effects.

Cimetidine, Famotidine, Ranitidine

name three H2 receptor blockers used in the treatment of ulcers and heartburn

NSAIDs, antiemetics, opioids

three non-specific treatments for migraine

5HT1 serotonin receptors

which receptor is blocked by anti-migraine drugs?

vasoconstriction

inhibited proinflammatory neuropeptide release on trigeminal nerve

what are the two effects of anti-migraine drugs?

sumatriptan

anti-migraine drug that is a 5HT 1B1D agonist on small peripheral nerves of intracranial vasculature causing vasoconstriction. Used to reduce the severity of headache.

ergotamine

dihydroergotamine

name two ergot alkaloids used in the treatment of migraine. They are 5HT 1D receptor agonists and also bind dopamine and alpha receptors to cause vasoconstriction of intracranial blood vessels

ergotamine

which ergot alkaloid is used in the early stages of migraine?

dihydroergotamine