Mephentermine

Mephentermine

Systematic (IUPAC) name
N,2-dimethyl-1-phenylpropan-2-amine
Clinical data
Routes of administration	IM/IV
Pharmacokinetic data
Metabolism	Rapidly demethylated in the body followed by hydroxylation.
Excretion	Via urine (as unchanged and metabolites); more rapid in acidic urine.
Identifiers
CAS Number	100-92-5 Y
ATC code	C01CA11 (WHO)
PubChem	CID: 3677
IUPHAR/BPS	7222
DrugBank	DB01365 Y
ChemSpider	3549 Y
UNII	TEZ91L71V4 Y
KEGG	D08180 Y
ChEMBL	CHEMBL1201234 N
Synonyms	methyl(2-methyl-1-phenylpropan-2-yl)amine
Chemical data
Formula	C11H17N
Molecular mass	163.259 g/mol
SMILES N(C(Cc1ccccc1)(C)C)C
InChI InChI=1S/C11H17N/c1-11(2,12-3)9-10-7-5-4-6-8-10/h4-8,12H,9H2,1-3H3 Y Key:RXQCGGRTAILOIN-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Mephentermine is a cardiac stimulant. It was formerly used in Wyamine nasal decongestant inhalers and before that as a stimulant in psychiatry.

It has been used as a treatment for low blood pressure.

ATC Classification: C01CA11 - mephentermine ; Belongs to the class of adrenergic and dopaminergic cardiac stimulants excluding glycosides. Used in the treatment of heart failure.

Mechanism of Action

Mephentermine appears to act by indirect stimulation of β-adrenergic receptors causing the release of norepinephrine from its storage sites. It has a positive inotropic effect on the myocardium. AV conduction and refractory period of AV node is shortened with an increase in ventricular conduction velocity. It dilates arteries and arterioles in the skeletal muscle and mesenteric vascular beds, leading to an increase in venous return.

Onset: 5–15 minutes (IM), immediate (IV).

Duration: 4 hr (IM), 30 minutes (IV).

Indication & Dosage

Maintenance of blood pressure in hypotensive states Adult: 30–45 mg as a single dose, repeated as necessary or followed by IV infusion of 0.1% mephentermine in 5% dextrose, rate and duration of administration will depend on patient's response.

Hypotension secondary to spinal anaesthesia in obstetric patients Adult: 15 mg as a single dose, repeat if needed.Maximum dose 30 mg.

Caution

Contraindications

Low blood pressure caused by phenothiazines. Hypertension. Pheochromocytoma.

Special Precautions

Patient on MAOIs. For shock due to loss of blood or fluid, give fluid replacement therapy primarily, CVS disease, hypertension, hyperthyroidism, chronic illnesses, lactation, pregnancy.

Adverse Drug Reactions

Drowsiness, incoherence, hallucinations, convulsions, slow heart rate (Reflex Bradycardia). Fear, anxiety, restlessness, tremor, insomnia, confusion, irritability, and psychosis. Nausea, vomiting, reduced appetite, urinary retention, dyspnea, weakness.

Potentially Fatal: AV block, CNS stimulation. Cerebral hemorrhage and pulmonary edema, ventricular arrhythmias.

Drug Interactions

Antagonizes effect of agents that lower blood pressure. Severe hypertension with MAOIs and possibly tricyclic antidepressants. Additive vasoconstricting effects with ergot alkaloids, oxytocin.

Potentially Fatal: Risk of abnormal heart rhythm in people undergoing anesthesia with cyclopropane and halothane.