The Word Choline Generally Refers to the Various Quaternary Ammonium Salts Containing

Cholinergic

Acetylcholine

The word choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation. Found in most animal tissues, choline is a primary component of acetylcholine, the neurotransmitter, and functions with inositol as a basic constituent of lecithin. It prevents fat deposits in the liver and facilitates the movement of fats into the cells. The richest sources of choline are liver, kidneys, brains, wheat germ, brewer's yeast, and egg yolk. Therefore, cholinergic often refers to the neurotransmitter acetylcholine,[1] and is typically used in a neurological perspective. The parasympathetic nervous system, which uses acetylcholine almost exclusively to send its messages, is said to be almost entirely cholinergic. Neuromuscular junctions, preganglionic neurons of the sympathetic nervous system, the basal forebrain, and brain stem complexes are also cholinergic. In addition, the receptor for the merocrine sweat glands are also cholinergic since acetylcholine is released from post ganglionic sympathetic neurons.

In neuroscience and related fields, the term cholinergic is used in the following related contexts:

· A substance (or ligand) is cholinergic if it is capable of producing, altering, or releasing acetylcholine ("indirect-acting") or mimicking its behaviour at one or more of the body's acetylcholine receptor types ("direct-acting").

· A receptor is cholinergic if it uses acetylcholine as its neurotransmitter.[2]

· A synapse is cholinergic if it uses acetylcholine as its neurotransmitter.

Cholinergic drug

Structure Activity Relationship for Cholinergic Drugs

1. molecule must possess a Nitrogen atom capable of bearing a positive charge, preferably a quarternary ammonium salt.

2. for maximum potency, the size of the alkyl groups substituted on the Nitrogen should not exceed the size of a methyl group.

3. The molecule should have an oxygen atom, preferably an ester-like oxygen capable of participating in a hydrogen bond.

4. There should be a two-carbon unit between the oxygen atom and the nitrogen atom.

A cholinergic drug, also known as a cholinergic agent, cholinergic agonist,[4] or a parasympathomimetic drug,[5] is any drug that functions to enhance the effects mediated by acetylcholine in the central nervous system, the peripheral nervous system, or both. These include acetylcholine's precursors and cofactors, acetylcholine receptor agonists,acetylcholinesterase inhibitors and cholinergic enzymes:

· Acetylcholine receptor agonists

o Alvameline

o Muscarine (muscarinic receptors)

o Nicotine (nicotinic receptors)

o Pilocarpine (M3 receptors)

o Suxamethonium (muscle type receptors)

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The N,N,N-trimethylethanolammonium cation, with an undefined counteranion, X−

Acetylcholine

In neuroscience and related fields, the term cholinergic is used in the following related contexts:

· A receptor is cholinergic if it uses acetylcholine as its neurotransmitter.[2]

· A synapse is cholinergic if it uses acetylcholine as its neurotransmitter.

Anticholinergic

An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine. Anticholinergics are administered to reduce the effects mediated by acetylcholine on acetylcholine receptors in neurons through competitive inhibition. Therefore, their effects are reversible.

Anticholinergics are a class of medications that inhibit parasympathetic nerve impulses by selectively blocking the binding of the neurotransmitter acetylcholine to its receptor in nerve cells. The nerve fibers of the parasympathetic system are responsible for the involuntary movements of smooth muscles present in the gastrointestinal tract, urinary tract, lungs, etc. Anticholinergics are divided into three categories in accordance with their specific targets in the central and/or peripheral nervous system: antimuscarinic agents, ganglionic blockers, and neuromuscular blockers.

Pharmacology

Anticholinergics are classified according to the receptors that are affected:

· Antimuscarinic agents operate on the muscarinic acetylcholine receptors. The majority of anticholinergic drugs are antimuscarinics.

· Antinicotinic agents operate on the nicotinic acetylcholine receptors. The majority of these are non-depolarising skeletal muscle relaxants for surgical use, along with a few of the depolarising agents and drugs of other categories structurally related to curare.

Examples of anticholinergics:

· ipratropium bromide (Atrovent)

· oxitropium bromide (Oxivent)

· tiotropium (Spiriva)

· Glycopyrrolate (Robinul)

Physostigmine is one of a few drugs that are used as antidotes for anticholinergic poisoning. Nicotine also counteracts anticholinergics.

Effects

Anticholinergic drugs are used in treating a variety of conditions:

· Gastrointestinal disorders (e.g., gastritis, pylorospasm, diverticulitis, ulcerative colitis)

· Genitourinary disorders (e.g., cystitis, urethritis, prostatitis)

· Respiratory disorders (e.g., asthma, chronic bronchitis)

· Parkinson's disease and Parkinson-like adverse medication effects

· Sinus bradycardia - Hypersensitive vagus nerve

· Insomnia, though usually only on a short term basis.

Anticholinergics generally have antisialagogue effects (decreasing saliva production), and most have at least some sedative effect, both being advantageous in surgical proceduresWhen a significant amount of an anticholinergic is taken into the body, a toxic reaction known as acute anticholinergic syndrome may result. This may happen accidentally or intentionally as a consequence of recreational drug use. Anticholinergic drugs are usually considered the least enjoyable by experienced recreational drug users,[citation needed] possibly due to the lack of euphoria caused by them. In terms of recreational use, these drugs are commonly referred to as deliriants. Because most users do not enjoy the experience, they do not use it again, or do so very rarely. The risk of addiction is low in the anticholinergic class. The effects are usually more pronounced in the elderly, due to natural reduction of acetylcholine production associated with age.

Exceptions to the above include scopolamine, orphenadrine, dicycloverine/dicyclomine and first-generation antihistamines with central nervous system penetration.

Possible effects of anticholinergics include:

· Ataxia; loss of coordination

· Decreased mucus production in the nose and throat; consequent dry, sore throat

· Xerostomia or dry-mouth with possible acceleration of dental caries

· Cessation of perspiration; consequent decreased epidermal thermal dissipation leading to warm, blotchy, or red skin

· Increased body temperature

· Pupil dilation (mydriasis); consequent sensitivity to bright light (photophobia)

· Loss of accommodation (loss of focusing ability, blurred vision — cycloplegia)

· Double-vision (diplopia)

· Increased heart rate (tachycardia)

· Tendency to be easily startled

· Urinary retention

· Diminished bowel movement, sometimes ileus - (decreases motility via the vagus nerve)

· Increased intraocular pressure; dangerous for people with narrow-angle glaucoma

· Shaking

Possible effects in the central nervous system resemble those associated with delirium, and may include:

· Confusion

· Disorientation

· Agitation

· Euphoria or dysphoria

· Respiratory depression

· Memory problems[2]

· Inability to concentrate

· Wandering thoughts; inability to sustain a train of thought

· Incoherent speech

· Wakeful myoclonic jerking

· Unusual sensitivity to sudden sounds

· Illogical thinking

· Photophobia

· Visual disturbances

o Periodic flashes of light

o Periodic changes in visual field

o Visual snow

o Restricted or "tunnel vision"

· Visual, auditory, or other sensory hallucinations

o Warping or waving of surfaces and edges

o Textured surfaces

o "Dancing" lines; "spiders", insects; form constants

o Lifelike objects indistinguishable from reality

o Hallucinated presence of people not actually there

· Rarely: seizures, coma, and death

Adrenergic agonist

An adrenergic agent is a drug, or other substance, which has effects similar to, or the same as, epinephrine (adrenaline). Thus, it is a kind of sympathomimetic agent. Alternatively, it may refer to something which is susceptible to epinephrine, or similar substances, such as a biological receptor (specifically, the adrenergic receptors).

Beta blockers block the action of epinephrine and norepinephrine in the body. Adrenergic drugs either stimulate a response (agonists) or inhibit a response (antagonists). The five categories of adrenergic receptors are: α1, α2, β1, β2, and β3, and agonists vary in specificity between these receptors, and may be classified respectively. However, there are also other mechanisms of adrenergic agonism. Epinephrine and norepinephrine are endogenous and broad-spectrum. More selective agonists are more useful in pharmacology.

Alpha-adrenergic agonist

An adrenergic alpha-agonist (or alpha-adrenergic agonist) is a drug that selectively stimulates alpha adrenergic receptors. The alpha-adrenergic receptor has two subclasses α1 and α2.

Classes

Although complete selectivity between receptor agonism is rarely achieved, some agents have partial selectivity.

α1 agonists

Main article: Alpha-1 adrenergic receptor#agonists

α1 agonists: stimulates phospholipase C activity. (vasoconstriction and mydriasis; used as vasopressors, nasal decongestants and eye exams). Selected examples are:

· Methoxamine

· Methylnorepinephrine

· Midodrine

· Oxymetazoline

· Phenylephrine [1]

α2 agonists

Main article: Alpha-2 adrenergic receptor#Agonists

α2 agonists: inhibits adenylyl cyclase activity. (reduce brainstem vasomotor center-mediated CNS activation; used as antihypertensives, sedatives & treatment of opiate and alcohol withdrawal symptoms). Selected examples are:

· Clonidine (mixed alpha2-adrenergic and imidazoline-I1 receptor agonist)

· Guanfacine,[2] (preference for alpha2A-subtype of adrenoceptor)

· Guanabenz (most selective agonist for alpha2-adrenergic as opposed to imidazoline-I1)

· Guanoxabenz (metabolite of guanabenz)

· Guanethidine (peripheral alpha2-receptor agonist)

· Xylazine,[3]

· Tizanidine

· Methyldopa

· Fadolmidine

Beta-adrenergic agonist

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Beta-adrenergic agonists are adrenergic agonists which act upon the beta receptors

β1 agonists

Main article: Beta-1 adrenergic receptor#agonists

β1 agonists: stimulates adenylyl cyclase activity; opening of calcium channel. (cardiac stimulants; used to treat cardiogenic shock, acute heart failure, bradyarrhythmias). Selected examples are:

· Dobutamine

· Isoproterenol (β1 and β2)

· Xamoterol

· epinephrine

β2 agonists

β2 agonists: stimulates adenylyl cyclase activity; closing of calcium channel (smooth muscle relaxants; used to treat asthma and COPD). Selected examples are:

· salbutamol)

· Fenoterol

· Formoterol

· Isoproterenol (β1 and β2)

· Metaproterenol

· Salmeterol

· Terbutaline

· Clenbuterol

· Isoetarine

· pirbuterol

· procaterol

· ritodrine

· epinephrin

Beta-adrenergic agonist

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Beta-adrenergic agonists are adrenergic agonists which act upon the beta receptors

β1 agonists

Main article: Beta-1 adrenergic receptor#agonists

β1 agonists: stimulates adenylyl cyclase activity; opening of calcium channel. (cardiac stimulants; used to treat cardiogenic shock, acute heart failure, bradyarrhythmias). Selected examples are:

· Dobutamine

· Isoproterenol (β1 and β2)

· Xamoterol

· epinephrine

β2 agonists

Main article: Beta2-adrenergic agonist

β2 agonists: stimulates adenylyl cyclase activity; closing of calcium channel (smooth muscle relaxants; used to treat asthma and COPD). Selected examples are:

· salbutamol (albuterol in USA)

· Fenoterol

· Formoterol

· Isoproterenol (β1 and β2)

· Metaproterenol

· Salmeterol

· Terbutaline

· Clenbuterol

· Isoetarine

· pirbuterol

· procaterol

· ritodrine

· epinephrin

Beta-adrenergic agonist

From Wikipedia, the free encyclopedia

Jump to: navigation, search

Beta-adrenergic agonists are adrenergic agonists which act upon the beta receptors

β1 agonists

Main article: Beta-1 adrenergic receptor#agonists

β1 agonists: stimulates adenylyl cyclase activity; opening of calcium channel. (cardiac stimulants; used to treat cardiogenic shock, acute heart failure, bradyarrhythmias). Selected examples are:

· Dobutamine

· Isoproterenol (β1 and β2)

· Xamoterol

· epinephrine

β2 agonists

Main article: Beta2-adrenergic agonist

β2 agonists: stimulates adenylyl cyclase activity; closing of calcium channel (smooth muscle relaxants; used to treat asthma and COPD). Selected examples are:

· salbutamol (albuterol in USA)

· Fenoterol

· Formoterol

· Isoproterenol (β1 and β2)

· Metaproterenol

· Salmeterol

· Terbutaline

· Clenbuterol

· Isoetarine

· pirbuterol

· procaterol

· ritodrine

· epinephrin

Mixed action

· Ephedrine

· Pseudoephedrine

Amphetamine (USAN) or amfetamine (INN) is a psychostimulant drug of the phenethylamine class which produces increased wakefulness and focus in association with decreased fatigue and appetite.

Brand names of medications that contain, or metabolize into, amphetamine include Adderall, Dexedrine, Dextrostat, Desoxyn, ProCentra, and Vyvanse, as well as Benzedrine in the past.

Physical effects of dextroamphetamine can include anorexia, hyperactivity, dilated pupils, blood shot eyes, flushing, restlessness, dry mouth, bruxism, headache, tachycardia, bradycardia, tachypnea, hypertension, hypotension, fever, diaphoresis, diarrhea, constipation, blurred vision, aphasia, dizziness, twitching, insomnia, numbness, palpitations, arrhythmias, tremors, dry and/or itchy skin, acne, pallor, convulsions, and with chronic and/or high doses, seizure, stroke, coma, heart attack and death can occur There is also significant research which highlights the possible neurotoxic effects of amphetamine on the dopaminergic system, even in clinical doses

Psychological effects

Psychological effects can include euphoria, anxiety, increased libido, alertness, concentration, energy, self-esteem, self-confidence, sociability, irritability, aggression, psychosomatic disorders, psychomotor agitation, grandiosity, excessive feelings of power and superiority, repetitive and obsessive behaviors, paranoia, and with chronic and/or high doses, amphetamine psychosis can occur.[11][12]

Withdrawal effects

Withdrawal symptoms of amphetamine primarily consist of mental fatigue, mental depression and an increased appetite. Symptoms may last for days with occasional use and weeks or months with chronic use, with severity dependent on the length of time and the amount of amphetamine used. Withdrawal symptoms may also include anxiety, agitation, excessive sleep, vivid or lucid dreams, deep REM sleep and suicidal ideation.[13][14][15]

Side effects

Contraindications

Amphetamine elevates cardiac output and blood pressure making it dangerous for use by patients with a history of heart disease or hypertension. Amphetamine can cause a life-threatening complication in patients taking MAOI antidepressants. The use of amphetamine and amphetamine-like drugs is contraindicated in patients with narrow-angle glaucoma or anatomically narrow angles. Like other sympathomimetic amines, amphetamine can induce transient mydriasis. In patients with narrow angles, pupillary dilation can provoke an acute attack of angle-closure glaucoma. These agents should also be avoided in patients with other forms of glaucoma, as mydriasis may occasionally increase intraocular pressure. Amphetamine has been shown to pass through into breast milk. Because of this, mothers taking amphetamine are advised to avoid breastfeeding during their course of treatment

Dependence and addiction

Tolerance is developed rapidly in amphetamine abuse; therefore, periods of extended use require increasing amounts of the drug in order to achieve the same effect

Overdose

An amphetamine overdose is rarely fatal but can lead to a number of different symptoms, including psychosis, chest pain, and hypertension.

Tyramine (4-Hydroxyphenethylamine; para-Tyramine; Mydrial, Uteramin) is a naturally-occurring monoamine compound and trace amine derived from the amino acid tyrosine.[1] Tyramine acts as a catecholamine (dopamine, norepinephrine (noradrenaline), epinephrine (adrenaline)) releasing agent. Notably, however, it is unable to cross the blood-brain-barrier (BBB), resulting in only non-psychoactive peripheral sympathomimetic effects. When ingested unintentionally from certain foods in conjunction with a monoamine oxidase inhibitor (MAOI), tyramine is responsible for the so-called "cheese effect" often seen with their use.