Definitions

advertisement
Definitions

Sympathetic and parasympathetic divisions typically function in opposition
to each other. But this opposition is better termed complementary in nature
rather than antagonistic. For an analogy, one may think of the sympathetic
division as the accelerator and the parasympathetic division as the brake.

The sympathetic division typically functions in actions requiring quick
responses.

The parasympathetic division functions with actions that do not require
immediate reaction.

Consider sympathetic as "fight or flight" and parasympathetic as "rest and
digest".
OH
OH
HO
NHMe
HO
NH2
HO
HO
Epinephrine
(Adrenaline)
Norepinephrine
(Noradrenaline)
•Epinephrine (INN) (IPA: [ˌɛpɪˈnɛfrən]) or adrenaline (European Pharmacopoeia and BAN)
(IPA: [əˈdrɛnələn]), sometimes spelled "epinephrin" or "adrenalin" respectively, is a hormone.
It is a catecholamine, a sympathomimetic monoamine derived from the amino acids
phenylalanine and tyrosine.
•The Latin roots ad-+renes and the Greek roots epi-+nephros both literally mean "on/to the
kidney" (referring to the adrenal gland, which secretes epinephrine). Epinephrine is
sometimes shortened to epi in medical jargon.
•Epinephrine is now also used in EpiPens and Twinjects. EpiPens are long narrow autoinjectors that administer epinephrine, Twinjects are similar but contain two doses of
epinephrine. Though both EpiPen and Twinject are trademark names, common usage of the
terms are drifting toward the generic context of any epinephrine autoinjector.
Anaphylaxis
Anaphylaxis is a severe and rapid multi-system allergic reaction. The term comes from the
Greek words ana (against) and phyllus (protection). Anaphylaxis occurs when a person is
exposed to a trigger substance, called an allergen, to which they have already become
sensitized. Minute amounts of allergens may cause a life-threatening anaphylactic reaction.
Anaphylaxis may occur after ingestion, inhalation, skin contact or injection of an allergen.
The most severe type of anaphylaxis—anaphylactic shock—will usually lead to death in
minutes if left untreated.
Most common presentation is sudden cardiovascular collapse (88% of reported cases of
severe anaphylaxis).
Anaphylactic shock
Anaphylactic shock, the most serious of allergic reactions, is a life-threatening medical
emergency because of rapid constriction of the airway, often within minutes of onset. Calling
for help immediately is important, as brain and organ damage rapidly occurs if the patient
cannot breathe. Anaphylactic shock requires immediate advanced medical care; but other
first aid measures include rescue breathing (part of CPR) and administration of epinephrine
(adrenaline). Rescue breathing may be hindered by the constricted airways but is essential
if the victim stops breathing on their own. If the patient has previously been diagnosed with
anaphylaxis, they may be carrying an EpiPen (or similar device) for immediate
administration of epinephrine (adrenaline) by a layperson to help keep the airway open. Use
of an EpiPen or similar device will only provide temporary and limited relief of symptoms, so
emergency medical services must still be contacted. Repetitive administration of
epinephrine can cause tachycardia (rapid heartbeat) and occasionally ventricular
tachycardia with heart rates potentially reaching 240 beats per minute, which can also be
fatal. Extra doses of epinephrine can sometimes cause cardiac arrest. This is why some
protocols advise intramuscular injection of only 0.3–0.5mL of a 1:1,000 dilution. The
epinephrine will prevent worsening of the airway constriction, stimulate the heart to continue
beating, and may be life-saving.
Ephinephrine can be injected directly into the heart to stimulate it
after it as stopped beating due to drowning, suffocation, shock,
electrocution, and anesthesia. The epinephrine dramatically restores
the heart beat. In cases of shock, norepinephrine has been used to
restore and maintain sufficient blood pressure and ensure adequate
blood flow to vital organs.
When local anesthetics are used to reduce or eliminate pain in a
specific area, epinephrine is frequently used in conjunction with
these agents to constrict the blood vessels at the area and prevent
drug diffusion from that area
1. Nerve Transmission
Peripheral nervous system
Skeletal
muscle
CNS
(Somatic)
CNS
(Autonomic)
Sympathetic
Ach
(N)
Synapse
Ach (N)
NA
Adrenaline
Parasympathetic
Ach
(N)
Adrenal
medulla
AUTONOMIC
Synapse
Ach
(N)
Ach
(M)
Smooth muscle
Cardiac muscle
 Noradrenaline released at junction of nerve with
smooth muscle and card iac muscle
 Adrenaline released by adrenal medulla and
circulates through blood supply (stimulates heart,
for exampl e)
 These two neurot ransmitters act opposite the
neurotransmitter acetylcholine
Biosynthesis of norepinephrine and epinephrine
CO2H
HO
HO
Tyrosine
NH2
hydroxylase
NH2
CO2H
HO
L-Tyrosine
HO
Dopa
Decarboxylase
OH
OH
HO
-hydroxylase
HO
Norepinephrine
(Noradrenaline)
HO
Dopamine
Levodopa
Dopamine
NH2
NH2
HO
NHMe
N-methyl transferase
(in Adrenal medulla)
HO
Epinephrine
(Adrenaline)
Metabolism involves two key enzymes: MAO and
COMT
OH
HO
HO
NH2
OH
Monoamine Oxidase
(MAO)
OH
NH
HO
H2O
HO
HO
Unstable Imine
Norepinephrine
(Noradrenaline)
OH
HO
O
OH
HO
Catechol-O-Methyl
Transferase
(COMT)
O
HO
OH
CH3O
O
OH
HO
The design of a drug to treat asthma

Asthma is a chronic disease of the respiratory system in which the airway
occasionally constricts, becomes inflamed, and is lined with excessive amounts of
mucus, often in response to one or more triggers. These acute episodes may be
triggered by such things as exposure to an environmental stimulant (or allergen), cold
air, exercise or exertion, or emotional stress. In children, the most common triggers
are viral illnesses such as those that cause the common cold.[1] This airway
narrowing causes symptoms such as wheezing, shortness of breath, chest tightness,
and coughing, which respond to bronchodilators. Between episodes, most patients
feel fine.The disorder is a chronic or recurring inflammatory condition in which the
airway develops increased responsiveness to various stimuli, characterized by
bronchial hyper-responsiveness, inflammation, increased mucus production, and
intermittent airway obstruction. The symptoms of asthma, which can range from mild
to life threatening, can usually be controlled with a combination of drugs and
environmental changes.Public attention in the developed world has recently focused
on asthma because of its rapidly increasing prevalence, affecting up to one in four
urban children.[2]
Download