Mephentermine was first described and introduced for medical use by 1952.[10] It was discontinued in the United States between 2000 and 2004.[2][7] The medication appears to remain available only in India.[4][7][8]Misuse of mephentermine for recreational and performance-enhancing purposes has been increasingly encountered in modern times, especially in India.[11][4]
Medical uses
For maintenance of blood pressure in hypotensive states, the dose for adults is 30 to 45mg as a single dose, repeated as necessary or followed by intravenous infusion of 0.1% mephentermine in 5% dextrose, with the rate and duration of administration depending on the patient's response.[citation needed]
For hypotension secondary to spinal anesthesia in obstetric patients, the dose for adults is 15mg as a single dose, repeated if needed. The maximum dose 30mg.[citation needed]
For shock due to loss of blood or fluid, give fluid replacement therapy primarily, cardiovascular disease, hypertension, hyperthyroidism, chronic illnesses, lactation, pregnancy, skin dryness. headache.[citation needed]
Side effects
The most common side effects of mephentermine are 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, and neck pain.[citation needed]
Potentially fatal reactions are due to atrioventricular block, central nervous system stimulation, cerebral hemorrhage, pulmonary edema, and ventricular arrhythmias.[citation needed]
Interactions
Mephentermine antagonizes effect of agents that lower blood pressure. Severe hypertension may occur with monoamine oxidase inhibitors and possibly tricyclic antidepressants. Additive vasoconstricting effects occur with ergot alkaloids, and oxytocin.[citation needed]
Potentially fatal drug interactions are the risk of abnormal heart rhythm in people undergoing anesthesia with cyclopropane and halothane.[citation needed]
Mephentermine appears to act by indirect stimulation of β-adrenergic receptors through 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.[citation needed]
The Henry (Nitro-Aldol) reaction between Benzaldehyde [100-52-7] (1) and 2-Nitropropane [79-46-9] (2) gives 2-methyl-2-nitro-1-phenylpropan-1-ol [33687-74-0] (3). The nitro group is reduced with zinc in sulfuric acid giving 2-Phenyl-1,1-dimethylethanolamine [34405-42-0] (4). Imine formation by dehydration with benzaldehyde gives CID:12640087 (5). Alkylation with iodomethane led to CID:10058106 (6). Halogenation with thionyl chloride gave CID:129921490 (7). Lastly, a Rosenmund reduction completed the total synthesis of mephentermine (8).
According to JACS, phentermine was condensed with benzaldehyde to get the Schiff-base. This was then alkylated with methyl iodide to give mephentermine.[17]
History
Mephentermine was first described in the literature and was introduced for medical use under the brand name Wyamine by 1952.[10] It was discontinued in the United States between 2000 and 2004.[2][7]
Society and culture
Names
Mephentermine is the generic name of the drug and its INNTooltip International Nonproprietary Name, BANTooltip British Approved Name, and DCFTooltip Dénomination Commune Française.[1][2][3] In the case of the sulfatesalt, its USANTooltip United States Adopted Name is mephentermine sulfate and its BANMTooltip British Approved Name is mephentermine sulphate.[3][2][7] Synonyms of mephentermine include mephetedrine and mephenterdrine.[2][7][9] Brand names of mephentermine include Wyamine (USTooltip United States), Fentermin (PTTooltip Portugal), and Mephentine (INTooltip India).[1][2][7]
Availability
Mephentermine is no longer available in the United States and remains available in few or no other countries.[7][8] However, it appears to remain available in India.[8][7] It has also remained available in Brazil for use in veterinary medicine.[5]
^ abcdefghijOliveira MF, Sousa HF, Lima MC, Oliveira JR (March 2011). "Mephentermine: rediscovering its biology and use, misuse and their implications". Braz J Psychiatry. 33 (1): 98–99. doi:10.1590/s1516-44462011000100019. PMID21537728.
^ abBrofman BL, Hellerstein HK, Caskey WH (September 1952). "Mephentermine: an effective pressor amine; clinical and laboratory observations". Am Heart J. 44 (3): 396–406. doi:10.1016/0002-8703(52)90261-5. PMID14952463.
^ abcSingh S, Gupta A, Sarkar S (2017). "Mephentermine Dependence in a Young Athlete: Case Report With Review of Literature". J Addict Med. 11 (4): 328–330. doi:10.1097/ADM.0000000000000313. PMID28574863.
^Hsu MC, Lin SF, Kuan CP, Chu WL, Chan KH, Chang-Chien GP (March 2009). "Oxethazaine as the source of mephentermine and phentermine in athlete's urine". Forensic Sci Int. 185 (1–3): e1–5. doi:10.1016/j.forsciint.2008.12.009. PMID19157735.
^Huang WH, Liu CH, Liu RH, Tseng YL (March 2010). "Confirming urinary excretion of mephentermine and phentermine following the ingestion of oxethazaine by gas chromatography-mass spectrometry analysis". J Anal Toxicol. 34 (2): 73–77. doi:10.1093/jat/34.2.73. PMID20223098.
^William F Bruce, Szabo Joseph Lester, Tubis Samuel, U.S. patent 2,597,445 (1952 to Wyeth Corp).
^Data, John B.; Skibbe, Martin O.; Kerley, T. Lamar; Weaver, Lawrence C. (1966). "Synthesis of N-Substituted Phenethylamines and Corresponding Cyclohexyl Analogs". Journal of Pharmaceutical Sciences. 55 (1): 38–43. doi:10.1002/jps.2600550108.
^Harvey E Alburn, Donald E Clark, & Norman H Grant, U.S. patent 3,300,510 (1967 to Wyeth LLC).
^Zenitz, Bernard L.; Macks, Elizabeth B.; Moore, Maurice L. (1948). "Preparation of α,α-Dimethyl- and N,α,α-Trimethyl-β-cyclohexylethylamine". Journal of the American Chemical Society. 70 (3): 955–957. doi:10.1021/ja01183a019.
^Angrist BM, Schweitzer JW, Gershon S, Friedhoff AJ (March 1970). "Mephentermine psychosis: misuse of the Wyamine inhaler". Am J Psychiatry. 126 (9): 1315–1317. doi:10.1176/ajp.126.9.1315. PMID5413209.
^Uday GJ, Josh UG, Bhat SM (January 1988). "Mephentermine dependence with psychosis. A case report". Br J Psychiatry. 152: 129–131. doi:10.1192/bjp.152.1.129. PMID3167321.
^de Sousa HF, de Oliveira MF, da Costa Lima MD, de Oliveira JR (June 2010). "Mephentermine dependence without psychosis: a Brazilian case report". Addiction. 105 (6): 1129–1130. doi:10.1111/j.1360-0443.2010.02935.x. PMID20456293.
^Gowda GS, Singh A, Ravi M, Math SB (October 2015). "Mephentermine dependence syndrome - A new emerging trend of substance use". Asian J Psychiatr. 17: 101–102. doi:10.1016/j.ajp.2015.07.006. PMID26236018.
^Frye RL, Kahler RL, Braunwald E (September 1961). "The ineffectiveness of an inotropic agent, mephentermine (Wyamine), in the treatment of congestive heart failure". Am Heart J. 62 (3): 301–303. doi:10.1016/0002-8703(61)90395-7. PMID13702337.