SNS (Sympathetic Nervous System ) (copy)

What is dopamine

,It is a neurotransmitter in the brain.

What are the precursor hormones of norepinephrine and epinephrine

,Dopamine is a precursor hormone of norepinephrine and epinephrine.

What happens in the absence of dopamine in the brain

,The deficiency of dopamine in the brain may cause Parkinsonism.

What is the action of dopamine at low concentrations

,At low concentrations, dopamine acts on dopaminergic receptor type 1 (D1), causing vasodilation in the renal, mesenteric and coronary vessels.

What is the benefit of dopamine's action on dopaminergic receptor type 1 (D1)

,It is useful in conditions with impaired renal function such as cardiogenic shock and hypovolemic shock.

What is the action of dopamine at somewhat higher concentrations

,At somewhat higher concentrations, dopamine stimulates B1-receptors of the heart, resulting in a positive inotropic effect.

What is the action of dopamine at high concentrations

,At high concentrations, dopamine stimulates vascular α1-receptors causing vasoconstriction of vessels including renal blood vessels, leading to decreased renal blood supply.

What are the therapeutic uses of dopamine

,Therapeutic uses of dopamine include shock (hypovolemic, cardiogenic, or septic), refractory congestive heart failure and acute heart failure following cardiac surgery (with dobutamine), and profound hypotension following the removal of pheochromocytoma.

What is Isoproterenol

,Isoproterenol, also known as isoprenaline, is a non-selective β-agonist that acts on β1 & β2 receptors, but has no action on α-receptors.

What are the therapeutic uses of Isoproterenol

,Isoproterenol is used for the treatment of patients with bradycardia and heart block as it increases the heart rate and conduction.

Why is Isoproterenol not used in bronchial asthma

,Isoproterenol is not used in bronchial asthma anymore because the selective β2-agonists are considered the best group for this condition.

What is Dobutamine

,Dobutamine is a racemic mixture used as a selective β1-agonist.

What is Dobutamine injection used for

,Dobutamine injection is used as a pharmacologic cardiac stress test in patients who cannot perform exercise during the stress test.

Which organs or tissues do selective B2-adrenergic agonists affect

,Selective B2-adrenergic agonists relax smooth muscle of the bronchi, uterus, and blood vessels

What is the effect of selective B2-adrenergic agonists on the heart

,Selective B2-adrenergic agonists have little effect on the heart

Is selectivity absolute for B2-receptors with these drugs

,No, selectivity is not absolute and is lost with large doses of these drugs.

What is the mechanism of action of selective B2-adrenergic agonists

,These drugs have relative specificity for B2-receptors, thus relax smooth muscle of bronchi, uterus, and blood vessels, with little effect on the heart but this selectivity is lost with large dose (selectivity is not absolute)

What are the two classifications of selective B2-adrenergic agonists

,1) Drugs used in asthma, 2) Drugs used in gynecology

What are the short-acting selective B2-adrenergic agonists used for in asthma treatment

,Short-acting selective B2-adrenergic agonists such as salbutamol and terbutaline are used orally and by inhalation in both chronic and acute asthma, as well as parenterally in status asthmatics.

What is the duration of action of short-acting selective B2-adrenergic agonists used in asthma treatment

,The duration of action of short-acting selective B2-adrenergic agonists used in asthma treatment is 3-6 hours.

What are the long-acting selective B2-adrenergic agonists used for in asthma treatment

,Long-acting selective B2-adrenergic agonists such as salmeterol and formoterol are used as maintenance treatment of chronic asthma. Formoterol can also be used in acute asthma due to its rapid onset of action.

What is the duration of action of long-acting selective B2-adrenergic agonists used in asthma treatment

,The duration of action of long-acting selective B2-adrenergic agonists used in asthma treatment is 12 hours.

What is the selective action of ritodrine and how is it used in gynecology

,Ritodrine has selective action on the uterus and is used intravenously to delay or prevent premature delivery. It is used as a tocolytic agent along with other drugs such as indomethacin, Ca++ channel blockers, and Mg++ sulphate.

What are the most common side effects of selective B2-adrenergic agonists

,The most common side effect of selective B2-adrenergic agonists is tremors, which are skeletal muscle in origin.

What is tolerance in relation to selective B2-adrenergic agonists

,Tolerance is the desensitization of receptors due to receptor down-regulation that can occur with the regular use of selective B2-adrenergic agonists.

What is tachycardia in relation to selective B2-adrenergic agonists

,Tachycardia is a side effect that can occur with the use of selective B2-adrenergic agonists.

What can happen with the regular long-term use of selective B2-adrenergic agonists in relation to bronchial asthma

,Regular long-term use of selective B2-adrenergic agonists may cause bronchial hyperreactivity with failure to control the disease. This can be avoided by the use of corticosteroids with these drugs.

What are some other potential side effects of selective B2-adrenergic agonists

,Other potential side effects of selective B2-adrenergic agonists include hyperglycemia and hypokalemia.

What is the mechanism of action of selective α1-adrenergic agonists

,Selective α1-adrenergic agonists stimulate α1-adrenergic receptors, leading to vasoconstriction and increased blood pressure.

What are the clinical uses of selective α1-adrenergic agonists

,Selective α1-adrenergic agonists such as phenylephrine and methoxamine are used in the treatment of hypotension and as nasal decongestants. They can also be used as mydriatics in ophthalmic procedures.

What is the difference between phenylephrine and methoxamine in their clinical use

,Phenylephrine is commonly used in the treatment of hypotension as during spinal anesthesia, as well as in nasal and eye decongestion. On the other hand, methoxamine is rarely used in the treatment of paroxysmal atrial tachycardia due to its potential to cause bradycardia.

What is midodrine

,Midodrine is a prodrug that is metabolized to an active form that activates α1-receptors.

What is the mechanism of action of midodrine

,Midodrine activates α1-receptors, leading to vasoconstriction and increased blood pressure.

What is the primary indication for midodrine

,The primary indication for midodrine is the treatment of orthostatic hypotension, typically due to impaired ANS function.

What is the mechanism of action of clonidine

,Clonidine acts by direct stimulation of α2-receptors, which causes a decrease in sympathetic outflow from the brain to the periphery, resulting in vasodilation and a decrease in blood pressure.

What are the two types of α2-receptors

,There are two types of α2-receptors: presynaptic α2-receptors present in the C.V. control center in the medulla and postsynaptic α2-receptors present in blood vessels.

What happens when presynaptic α2-receptors are stimulated

,Stimulation of presynaptic α2-receptors causes a decrease in sympathetic outflow from the brain to the periphery, resulting in vasodilation and a decrease in blood pressure.

What happens when postsynaptic α2-receptors are stimulated

,Stimulation of postsynaptic α2-receptors causes vasoconstriction and an increase in blood pressure.

What is the effect of yohimbine on α2-receptors

,Both presynaptic and postsynaptic α2-receptors are blocked by yohimbine.

Does clonidine act on both types of α2-receptors

,Yes, clonidine acts on both types of α2-receptors, but it mainly acts on presynaptic α2-receptors causing vasodilation and a decrease in blood pressure.

Does the action of clonidine on postsynaptic α2-receptors appear on oral use

,No, the action of clonidine on postsynaptic α2-receptors does not appear on oral use.

When does the action of clonidine on postsynaptic α2-receptors appear

,The action of clonidine on postsynaptic α2-receptors appears only on IV infusion as a transient rise in blood pressure followed by prolonged hypotension due to presynaptic action

What is the oral bioavailability of Clonidine

,The oral bioavailability of Clonidine is nearly 100%.

How can Clonidine be administered transdermally

,Clonidine can be administered transdermally in the form of a patch, with the action lasting for 7 days.

What is the therapeutic use of Clonidine in hypertension

,Clonidine is used as a second or third line in hypertension.

What is the therapeutic use of Clonidine in diabetic patients with autonomic neuropathy

,Clonidine is used to treat diarrhea in diabetic patients with autonomic neuropathy.

What is the therapeutic use of Clonidine in suppressing narcotic and alcohol withdrawal manifestations

,Clonidine is used to suppress narcotic and alcohol withdrawal manifestations.

What is the therapeutic use of Clonidine in smoking cessation

,Clonidine is used to help in cessation of smoking.

What is the therapeutic use of Clonidine in decreasing the dose of anesthesia and analgesia

,Clonidine is used to decrease the dose of anesthesia and analgesia and improve cardiac stability.

What is the therapeutic use of Clonidine in decreasing the incidence of menopausal hot flashes

,Clonidine is used to decrease the incidence of menopausal hot flashes through transdermal use.

What is the therapeutic use of Clonidine in diagnosing pheochromocytoma

,Clonidine is used in the diagnosis of pheochromocytoma.

What is the topical use of Clonidine in the eye

,Clonidine is used topically to the eye to decrease I.O.P. in cases of postlaser glaucoma.

What is Clonidine used for

,Clonidine is used for hypertension, diarrhea in diabetic patients with autonomic neuropathy, suppressing narcotic and alcohol withdrawal manifestations, cessation of smoking, decreasing dose of anesthesia and analgesia and improving cardiac stability, decreasing incidence of menopausal hot flashes, and diagnosing pheochromocytoma. It is also used topically to the eye to decrease I.O.P. in cases of postlaser glaucoma.

What is α-methyl dopa

,α-methyl dopa is a medication used for the treatment of hypertension.

What is the mechanism of action of α-methyl dopa

,α-methyl dopa is changed to α-methyl dopamine and then to α-methyl norepinephrine, which is a potent stimulator of presynaptic receptors in the brain stem. This leads to a decrease in blood pressure.

What is the effect of α-methyl dopa on salt and water retention

,α-methyl dopa causes salt and water retention gradually, which decreases its hypotensive effect (pseudo-tolerance).

What are the therapeutic uses of α-methyl dopa

,The therapeutic uses of α-methyl dopa include the treatment of hypertension. It is not a first choice monotherapy drug due to many side effects. However, it is preferable in the treatment of hypertension during pregnancy (preeclampsia) due to its effectiveness and safety to the mother and the fetus.

What is the effectiveness of α-methyl dopa in treating hypertension during pregnancy

,α-methyl dopa is effective in treating hypertension during pregnancy (preeclampsia) and is preferred due to its safety to the mother and the fetus.

What is the safety profile of α-methyl dopa during pregnancy

,α-methyl dopa is safe to use during pregnancy for the treatment of hypertension, particularly in cases of preeclampsia.

Why is α-methyl dopa not a first choice monotherapy drug for hypertension

,α-methyl dopa is not a first choice monotherapy drug for hypertension due to its many side effects.

What is the recommended use of α-methyl dopa in combination with other medications for hypertension

,α-methyl dopa is recommended to be used in combination with diuretics for the treatment of hypertension.

What are xylometazoline and oxymetazoline

,Xylometazoline and oxymetazoline are direct-acting α-agonists.

What is the mechanism of action of xylometazoline and oxymetazoline

,The mechanism of action of xylometazoline and oxymetazoline is their ability to promote constriction of the nasal mucosa and conjunctiva.

What is the therapeutic use of xylometazoline and oxymetazoline

,The therapeutic use of xylometazoline and oxymetazoline is as topical decongestants due to their ability to promote constriction of the nasal mucosa and conjunctiva.

What is the advantage of using xylometazoline and oxymetazoline as topical decongestants

,The advantage of using xylometazoline and oxymetazoline as topical decongestants is their direct-acting mechanism of action, which promotes constriction of the nasal mucosa and conjunctiva.

What is mirabegron

,Mirabegron is a selective β3-agonist.

What is the therapeutic use of mirabegron

,Mirabegron is used to treat overactive urinary bladder disease by reducing urinary bladder tone through action on beta-3 receptors in the urinary bladder that relax detrusor muscle.

What is the mechanism of action of mirabegron

,The mechanism of action of mirabegron is activation of beta-3 receptors in the urinary bladder, leading to relaxation of detrusor muscle and reduction in urinary bladder tone. It also activates beta-3 receptors in adipose tissue, leading to lipolysis and potential use in the treatment of obesity.

How is mirabegron administered

,Mirabegron is administered orally.

What is the duration of action of mirabegron

,The duration of action of mirabegron is longer, approximately 50 hours.

What is the main side effect of mirabegron

,Hypertension is the main side effect of mirabegron.

What are indirect acting agonists

,They act by releasing norepinephrine from sympathetic nerve endings.

What is the mechanism of action of indirect acting agonists

,Indirect acting agonists act by releasing norepinephrine from sympathetic nerve endings.

What is the pharmacological action of amphetamine on the cardiovascular system

,Amphetamine acts as a norepinephrine agonist and increases both systolic and diastolic blood pressure. However, heart rate may decrease due to a reflex mechanism.

What is the pharmacological action of amphetamine on the CNS

,Amphetamine is a powerful CNS stimulant, and its effects are more pronounced with the D-isomer. It increases locomotor activity, elevates mood, improves concentration, and produces self-confidence and euphoria.

What is the analgesic action of amphetamine

,Amphetamine has mild analgesic action.

What is the appetite suppressant action of amphetamine

,Amphetamine acts on the lateral hypothalamic feeding center and leads to decreased food intake (anorectic effect) and weight reduction.

What is the effect of amphetamine on physical performance

,Amphetamine prevents and reverses fatigue and improves physical performance due to its antifatigue action.

What is the effect of amphetamine on respiration

,Amphetamine stimulates medullary centers and increases the rate and depth of respiration.

What is the therapeutic use of amphetamine

,Amphetamine is used for its CNS effects, with the D-isomer (dextroamphetamine) being used in particular.

What is narcolepsy

,Narcolepsy is a sleep disorder in which attacks of sleep occur suddenly under unsuitable conditions.

Which isomer of amphetamine is used for narcolepsy

,The D-isomer (dextroamphetamine) is used for narcolepsy.

Is amphetamine used at night for narcolepsy

,No, amphetamine is not used at night for narcolepsy as it may cause disturbance of normal sleep.

What is another therapeutic use of amphetamine besides narcolepsy

,Amphetamine is also used in obesity as it has an ==anorectic== effect, but it must be used with dietary restrictions.

What is attention deficit hyperactivity disorder (ADHD)

,Attention deficit hyperactivity disorder (ADHD) is a disorder that commonly occurs in children, characterized by excessive motor activity and difficulty in attention.

Is amphetamine used to treat ADHD

,Yes, amphetamine is used to treat ADHD.

What is the illegal use of amphetamine

,Some athletes use amphetamine illegally to increase muscular activity

What are sympatholytics

,Sympatholytics are adrenergic blocking drugs that include adrenergic receptor blocking drugs and adrenergic neuron blocking drugs.

What do adrenergic receptor blocking drugs do

,Adrenergic receptor blocking drugs block adrenergic receptors.

What do adrenergic neuron blocking drugs do

,Adrenergic neuron blocking drugs prevent the release or cause depletion of the storage of norepinephrine, as seen with guanadrel and reserpine which are used in the treatment of severe hypertension.

What are the types of non-selective α-blockers

,The types of non-selective α-blockers include irreversible blockers (such as phenoxybenzamine), competitive blockers (such as phentolamine and tolazoline), and ergot alkaloids.

What are the types of selective α1-blockers

,The types of selective α1-blockers include prazosin and its congeners (such as terazosin, doxazosin, and tamsulosin).

What is the selective α2-blocker

,Yohimbine is a selective α2-blocker.

What are non-selective B-blockers

,Non-selective B-blockers include propranolol, pindolol, timolol, and nadolol. (TNPP)

What are selective B1-blockers

,Selective B1-blockers include atenolol, acebutolol, esmolol, and metoprolol (EMAA).

What are the third-generation beta-blockers

,The third-generation beta-blockers include carvedilol, carteolol, labetalol, celiprolol, nebivolol, and betaxolol. (LBN CCC)

What are the natural alkaloids of ergot alkaloids

,Ergotamine, Ergometrine (ergonovine), Ergotoxine (mixture of 3 alkaloids), Methylsergide.

What are the synthetic (dihydrogenated alkaloids) of ergot alkaloids

,Dihydroergotamine (DHE or Migranal), Hydrogenated ergotoxine (hydergin), Methylergonovine (Methergine).

What is the therapeutic use of ergotamine

,Control of acute attack of migraine.

How does ergotamine control migraine

,It causes vasoconstriction of meningeal vessels due to partial agonism on 5-HT and α- receptors.