Drugs Acting At The ANS - Adrenergic Receptors. Flashcards
What two types of receptors do NA act on?
Alpha and Beta. Generally alpha excitation, Beta relaxation of effector cells.
List in order of sensitivity the types of chemicals which react with alpha adrenoreceptors.
Noradrenaline>Adrenaline>Isoprenaline.
List in order of sensitivity the types of chemicals which react with beta adrenoreceptors.
Isoprenaline>Adrenaline>Noradrenaline.
Effects of Alpha 1 adrenoreceptor stimulation.
Vasoconstricion, GI smooth muscle relaxation, Salivary secretion (going to eat) and hepatic glycgenolysis (give energy to eat). NASAL AND OCULAR DECONGESTANTS.
Effects of Alpha 2 adrenoreceptor stimulaiton.
Vasoconstriciton (post junctional), Inihibition of transmitter release (pre junctional), inibition of insulin release. Platelet aggregation.
Effects of Beta 1 adrenoreceptor stimulation.
Increased cardiac rate and force.
Effects of Beta 2 adrenoreceptor stimulation.
Vasodilation in muscle, Brochodilation, Relaxation of visceral smooth muscle, Hepatic glycogenolysis.
Effects of Beta 3 adrenoreceptor stimulation.
Lipolysis.
Noradrenaline synthesis.
Tyrosine to DOPA, then Dopamine, Noradrenaline and finally Adrenaline.
What drug would you give to increase levels of dopamine in the brain?
Levodopa.
How does Levodopa increase levels of Dopamine?
Levodopa increase levels of DOPA which is converted by DOPA carboxylase into Dopamine.
What enzymes are involved in the conversion of Tyrosine to adrenaline.
Hydroxylase, Decarboxylase, Beta Hydroxylase, Phenylethanoloamine N-methyltransferase.
What should you give along with Levodopa?
A peripheral DOPA decarboxylase inhibitor. This should be given to prevent dopamine production in the peripheral nervous system and prevent hyperdopaminergia.
Hyperdopaminergia is associated with what?
Schizophrenia.
Reserpine.
Blocks vesicle transport of Noradrenaline.
Drugs which affect NA storage.
Reserpina, MAO inhibitors.
Drugs blocking the release of NA.
Guanethidine, Bretylium, go through uptake 1 and abolish response to nerve stimulation.
Drugs which cause NA release even without nerve stimulation.
Tyramine, Amphetamines and Ephedrine. Enter via uptake 1, displace NA from vesicles. Cause effects similar to NA in the sympathetic nervous system.
Drugs that increase or decrease release of NA?
Stuff that affect alpha 2 receptors.
Types of MAO inhibitors.
Moclobemide - depression, Pargyline, Selegeline - parkinson’s disease.
Tyramine cheese reaction.
When food containing tyramine is consumed and the patient is taking a MAO inhibitor, there is the chance that the patient may suffer a hypertensive crisis.
Problem with MAOI.
When ingested orally they affected the digestion of dietary amines.
Hypertensive crisis.
Malignant hypertension - cause acute impairment of one or more organ systems. The blood pressure should be lowered slowly. SYSTOLIC > 180, DIASTOLIC > 120.
Use of pseudoephedrine?
Nasal Decongestant.
