Rats' systemic circulation is more affected by methylamine hydrochloride (0.025 mg/kg; femoral vein) on peripheral resistance vessels than Winkessel vessels [2].

Animal/Disease Models: Male Wistar-Kyoto rat, body weight 320-47 g (based on exponential tapered T-tube model) [2]
Doses: 0.025 mg/kg
Route of Administration: Femoral vein
Experimental Results: The effect on peripheral resistance vessels is greater than that on peripheral blood vessels Effects of resistance vessels on the Winksel vessels in the rat systemic circulation.

Interactions
...METHOXAMINE MAY PRODUCE CARDIAC ARRHYTHMIAS WHEN USED WITH GENERAL ANESTHETIC AGENTS. /METHOXAMINE/
METHOXAMINE HYDROCHLORIDE HAS BEEN TESTED AS 2% EYEDROPS ON THE THYROTOXIC PATIENTS & FOUND TO CAUSE MYDRIASIS & WIDENING OF THE PALPEBRAL FISSURE. THIS EFFECT HAS BEEN SHOWN TO BE POTENTIATED BY GUANETHIDINE.
WHEN VAGAL EFFECTS ARE BLOCKED BY ATROPINE, METHOXAMINE /HCL/ OFTEN SLOWS THE HEART SLIGHTLY. THIS IS PROBABLY DUE TO DIRECT ACTION ON ALPHA RECEPTORS. INJECTION OF THE DRUG INTO THE ARTERY LEADING TO THE SINUS NODE SLOWS THE HEART, AN EFFECT BLOCKED BY PHENTOLAMINE.
Concurrent use /with alpha-adrenergic-blocking agents such as: doxazosin, labetalol, phenoxybenzamine, phentolamine, prazosin, terazosin, tolazoline or with other medications with alpha-adrenergic blocking action, such as: haloperidol, loxapine, phenothiazines, thioxanthenes/ may antagonize the peripheral vasoconstriction of sympathomimetic agents; however, phentolamine may be used for therapeutic benefit. /Sympathomimetic agents/
For more Interactions (Complete) data for METHOXAMINE HYDROCHLORIDE (17 total), please visit the HSDB record page.

---

Non-Human Toxicity Values
LD50 Mouse ip 92 mg/kg
LD50 Mouse iv 5030 ug/kg

[1]. Sanders AB. The roles of methoxamine and norepinephrine in electromechanical dissociation. Ann Emerg Med. 1984;13(9 Pt 2):835-839.

[2]. Chang KC. Hypertensive effects of methoxamine on arterial mechanics in rats: analysis based on exponentially tapered T-tube model. Eur J Pharmacol. 1998;350(2-3):195-202.

[3]. Methoxamine-induced release of endogenous ATP from rabbit pulmonary artery. Eur J Pharmacol. 1994;254(3):287-290.

Methoxamine hydrochloride is a dimethoxybenzene.
An alpha-1 adrenergic agonist that causes prolonged peripheral VASOCONSTRICTION.

---

Mechanism of Action
ITS PHARMACOLOGICAL PROPERTIES ARE ALMOST EXCLUSIVELY THOSE CHARACTERISTIC OF ALPHA-RECEPTOR STIMULATION, SINCE IT ACTS DIRECTLY AT THESE SITES. ... THE OUTSTANDING EFFECT IS AN INCREASE IN BLOOD PRESSURE DUE ENTIRELY TO VASOCONSTRICTION.
METHOXAMINE, GIVEN INTRAVENOUSLY OR INTRAMUSCULARLY IN MAN, CAUSES A RISE IN SYSTOLIC & DIASTOLIC BLOOD PRESSURES THAT PERSISTS FOR 60 TO 90 MINUTES. THE PRESSOR EFFECT IS DUE ALMOST EXCLUSIVELY TO AN INCREASE IN PERIPHERAL RESISTANCE. CARDIAC OUTPUT IS DECREASED OR UNCHANGED. /METHOXAMINE/
METHOXAMINE HAS A RELATIVELY SELECTIVE ACTION ON POSTSYNAPTIC COMPARED WITH PRESYNAPTIC RECEPTOR OF PULMONARY ARTERY; BOTH SYSTEMS WERE OF SIMILAR SENSITIVITY TO NOREPINEPHRINE & EPINEPHRINE.
TRITIUM-LABELED METHOXAMINE CROSSED THE BLOOD-BRAIN BARRIER IN RAT. THUS METHOXAMINE IS CENTRALLY ACTIVE ALPHA-ADRENERGIC AGONIST & CONCEPT THAT HYPOTHALAMIC ADRENERGIC MECHANISMS ARE INVOLVED IN ELECTROENCEPHALOGIC & BEHAVIORAL AROUSAL IS SUPPORTED.

---

Therapeutic Uses
Adrenergic alpha-Agonists; Sympathomimetics; Vasoconstrictor Agents
Methoxamine may be used intravenously in the treatment of hypotensive states or to relieve attacks of paroxysmal atrial tachycardia, particularly those associated with hypotension. /Methoxamine/
METHOXAMINE ... DOES NOT INCREASE VENTRICULAR RATE IN PATIENTS WITH HEART BLOCK. REFLEX BRADYCARDIA IS PROMINENT, &, THEREFORE, THE DRUG IS USED CLINICALLY TO RELIEVE ATTACKS OF PAROXYSMAL ATRIAL TACHYCARDIA. /METHOXAMINE/
THE DRUG IS USEFUL FOR THE TREATMENT OF HYPOTENSIVE STATES WHEN IT IS DESIRED TO RAISE BLOOD PRESSURE WITHOUT CARDIAC STIMULATION. HOWEVER, METHOXAMINE HAS VERY LITTLE EFFECT ON THE CAPACITANCE VEINS, SO THAT ITS USEFULNESS IS COMPROMISED, ESPECIALLY IN TREATMENT OF VARIOUS KINDS OF SHOCK.
For more Therapeutic Uses (Complete) data for METHOXAMINE HYDROCHLORIDE (9 total), please visit the HSDB record page.

---

Drug Warnings
Methoxamine should be used with caution in patients with hyperthyroidism, bradycardia, partial heart block, myocardial disease, or severe arteriosclerosis. Caution should be used to avoid overdosage of methoxamine, since it may cause undesirable hypertension and/or bradycardia.
Methoxamine can cause ventricular ectopic beats or severe bradycardia and decreased cardiac output. Decreased cardiac output may be especially harmful to geriatric patients and/or those with preexisting poor cerebral or coronary circulation. Bradycardia may be treated by administration of atropine. Methoxamine also increases cardiac work by increasing peripheral arterial resistance and may induce or exacerbate heart failure associated with a decreased myocardium. Some clinicians believe that the drug is contraindicated in shock caused by myocardial infarction. Large doses of methoxamine, especially if administered following repeated injections of the drug, may cause cardiac depression and a fall in blood pressure.
Methoxamine can cause severe peripheral and visceral vasoconstriction, reduced blood blow to vital organs, and decreased renal perfusion; reductions in glomerular filtration rate, urine output, and sodium excretion may occur as well as metabolic acidosis. These effects may be most likely to occur in hypovolemic patients. In addition, prolonged use of the drug may result in plasma volume depletion which may result in perpetuation of the shock state or the recurrence of hypotension when methoxamine is discontinued.
Methoxamine may cause restlessness, anxiety, nervousness, weakness, dizziness, precordial pain, tremor, respiratory distress, sweating, or pallor. Occasionally, injections of the drug may be followed by paresthesia in the extremities or feeling of coldness. A desire to void, a pilomotor response, and/or nausea and vomiting (often projectile) may also occur, especially with high doses. In addition, large doses of methoxamine may cause severe prolonged hypertension and severe headaches. Seizures and cerebral hemorrhage may result.
For more Drug Warnings (Complete) data for METHOXAMINE HYDROCHLORIDE (8 total), please visit the HSDB record page.

C11H17NO3.HCL

247.72

247.098

61-16-5

Methoxamine;390-28-3

6081

White to off-white solid powder

368.4ºC at 760 mmHg

212-216ºC

176.6ºC

1.5204

2.586

3

4

4

16

189

0

YGRFXPCHZBRUKP-UHFFFAOYSA-N

InChI=1S/C11H17NO3.ClH/c1-7(12)11(13)9-6-8(14-2)4-5-10(9)15-3;/h4-7,11,13H,12H2,1-3H3;1H

2-amino-1-(2,5-dimethoxyphenyl)propan-1-ol;hydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~135 mg/mL (~544.97 mM)

Solubility in Formulation 1: ≥ 2 mg/mL (8.07 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

---

Solubility in Formulation 2: ≥ 2 mg/mL (8.07 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

 (Please use freshly prepared in vivo formulations for optimal results.)