Perphenazine is a relatively high potency phenothiazine that blocks dopamine 2 receptors predominantly, but also may possess antagonist actions at histamine 1 and cholinergic M1 and alpha 1 adrenergic receptors in the vomiting center leading to reduced nausea and vomiting. The drug was approved by FDA for the treatment of schizophrenia and control of severe nausea and vomiting (either alone or in combination with amitriptyline hydrochloride). Perphenazine is extensively hepatic to metabolites via sulfoxidation, hydroxylation, dealkylation, and glucuronidation; primarily metabolized by CYP2D6 to N-dealkylated perphenazine, perphenazine sulfoxide, and 7-hydroxyperphenazine (active metabolite with 70% of the activity of perphenazine) and excreted in the urine and feces.

Metaraminol is a potent sympathomimetic amine that increases both systolic and diastolic blood pressure, is an adrenergic receptor alpha-1 agonist.. Metaraminol is indicated for prevention and treatment of the acute hypotensive state occurring with spinal anesthesia. It is also indicated as adjunctive treatment of hypotension due to hemorrhage, reactions to medications, surgical complications, and shock associated with brain damage due to trauma or tumor. Metaraminol is also used in the treatment of priapism, in spite of this application was not approved, it appears to be effective.

Metaraminol is a potent sympathomimetic amine that increases both systolic and diastolic blood pressure, is an adrenergic receptor alpha-1 agonist.. Metaraminol is indicated for prevention and treatment of the acute hypotensive state occurring with spinal anesthesia. It is also indicated as adjunctive treatment of hypotension due to hemorrhage, reactions to medications, surgical complications, and shock associated with brain damage due to trauma or tumor. Metaraminol is also used in the treatment of priapism, in spite of this application was not approved, it appears to be effective.

Phentolamine (trade name Regitine) is a reversible nonselective α-adrenergic antagonist used for the control of hypertensive emergencies, most notably due to pheochromocytoma. Phentolamine produces its therapeutic actions by competitively blocking alpha-adrenergic receptors (primarily excitatory responses of smooth muscle and exocrine glands), leading to a muscle relaxation and a widening of the blood vessels. This widening of the blood vessels results in a lowering of blood pressure. The action of phentolamine on the alpha-adrenergic receptors is relatively transient and the blocking effect is incomplete. The drug is more effective in antagonizing responses to circulating epinephrine and/or norepinephrine than in antagonizing responses to mediator released at the adrenergic nerve ending. Phentolamine also stimulates β-adrenergic receptors and produces a positive inotropic and chronotropic effect on the heart and increases cardiac output. Phentolamine is indicated for the prevention or control of hypertensive episodes that may occur in a patient with pheochromocytoma as a result of stress or manipulation during preoperative preparation and surgical excision. Phentolamine is indicated for the prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine. Phentolamine is also indicated for the diagnosis of pheochromocytoma by the Phentolamine blocking test. Acute and prolonged hypotensive episodes, tachycardia, and cardiac arrhythmias have been reported. In addition, weakness, dizziness, flushing, orthostatic hypotension, nasal stuffiness, nausea, vomiting, and diarrhea may occur.

Phentolamine (trade name Regitine) is a reversible nonselective α-adrenergic antagonist used for the control of hypertensive emergencies, most notably due to pheochromocytoma. Phentolamine produces its therapeutic actions by competitively blocking alpha-adrenergic receptors (primarily excitatory responses of smooth muscle and exocrine glands), leading to a muscle relaxation and a widening of the blood vessels. This widening of the blood vessels results in a lowering of blood pressure. The action of phentolamine on the alpha-adrenergic receptors is relatively transient and the blocking effect is incomplete. The drug is more effective in antagonizing responses to circulating epinephrine and/or norepinephrine than in antagonizing responses to mediator released at the adrenergic nerve ending. Phentolamine also stimulates β-adrenergic receptors and produces a positive inotropic and chronotropic effect on the heart and increases cardiac output. Phentolamine is indicated for the prevention or control of hypertensive episodes that may occur in a patient with pheochromocytoma as a result of stress or manipulation during preoperative preparation and surgical excision. Phentolamine is indicated for the prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine. Phentolamine is also indicated for the diagnosis of pheochromocytoma by the Phentolamine blocking test. Acute and prolonged hypotensive episodes, tachycardia, and cardiac arrhythmias have been reported. In addition, weakness, dizziness, flushing, orthostatic hypotension, nasal stuffiness, nausea, vomiting, and diarrhea may occur.

The isolation and naming of ergotamine by Stoll occurred in 1925 but the complete elucidation of structure was not achieved until 1951, with synthesis following some 10 years later. Current sources of ergotamine include the isolation from field ergot and fermentation broth, as well as synthesis via coupling of (+)-lysergic acid with the appropriate synthetic peptidic moiety. Ergotamine was introduced into world commerce in 1921, and is currently marketed as its water soluble tartrate salt. Ergotamine is a partial agonist at various tryptaminergic receptors (including the serotonin receptor [5-HT2]) and at various α-adrenergic receptors in blood vessels and various smooth muscles. It is likely that the major activity of ergotamine and related alkaloids is one of agonism at the 5-HT1B/1D receptors, just as with the “triptan” antimigraine compounds. FDA-labeled indications for ergotamine tartrate are in the abortion or prevention of vascular headaches, such as migraine, migraine variant, cluster headache, and histaminic cephalalgia.

Ephedrine (l-form) is an alkaloid, which was initially purified from Ephedra plant. The extract form Ephedra has been used in China for medicinal purposes for several thousand years. Ephedrine acts as an agonist at alpha- and beta-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. The drug crosses the blood brain barrier and stimulates the central nervous system. Ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. FDA has approved ephedrine only for the treatment of clinically important hypotension occurring in the setting of anesthesia.

Ephedrine (l-form) is an alkaloid, which was initially purified from Ephedra plant. The extract form Ephedra has been used in China for medicinal purposes for several thousand years. Ephedrine acts as an agonist at alpha- and beta-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. The drug crosses the blood brain barrier and stimulates the central nervous system. Ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. FDA has approved ephedrine only for the treatment of clinically important hypotension occurring in the setting of anesthesia.

Ephedrine (l-form) is an alkaloid, which was initially purified from Ephedra plant. The extract form Ephedra has been used in China for medicinal purposes for several thousand years. Ephedrine acts as an agonist at alpha- and beta-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. The drug crosses the blood brain barrier and stimulates the central nervous system. Ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. FDA has approved ephedrine only for the treatment of clinically important hypotension occurring in the setting of anesthesia.

Ephedrine (l-form) is an alkaloid, which was initially purified from Ephedra plant. The extract form Ephedra has been used in China for medicinal purposes for several thousand years. Ephedrine acts as an agonist at alpha- and beta-adrenergic receptors and indirectly causes the release of norepinephrine from sympathetic neurons. The drug crosses the blood brain barrier and stimulates the central nervous system. Ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine. FDA has approved ephedrine only for the treatment of clinically important hypotension occurring in the setting of anesthesia.