D-METHAMPHETAMINE

Absorption

Methamphetamine is rapidly absorbed from the gastrointestinal tract with peak methamphetamine concentrations occurring in 3.13 to 6.3 hours post ingestion. Moreover, when administered intranasally or as an inhalation, methamphetamine also demonstrates a high degree of absorption. It is distributed to most parts of the body. Because methamphetamine has a high lipophilicity it is distributed across the blood brain barrier and crosses the placenta.

Toxicity

Manifestations of acute overdosage with methamphetamine include restlessness, tremor, hyperreflexia, rapid respiration, confusion, assaultiveness, hallucinations, panic states, hyperpyrexia, and rhabdomyolysis. Fatigue and depression usually follow the central stimulation. Cardiovascular effects include arrhythmias, hypertension or hypotension, and circulatory collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhea, and abdominal cramps. Fatal poisoning usually terminates in convulsions and coma.

Originator

Desoxyn ,Abbott Laboratories

The Uses of D-METHAMPHETAMINE

Nasal decongestant.

Background

Metamfetamine (methamphetamine) is a psychostimulant and sympathomimetic drug, and a member of the amphetamine group of sympathomimetic amines. Methamphetamine can induce effects such as euphoria, increased alertness and energy, and enhanced self-esteem. It is a scheduled drug in most countries due to its high potential for addiction and abuse.
The FDA withdrew its approval for the use of all parenteral drug products containing methamphetamine hydrochloride, a metamfetamine salt.

Indications

For the treatment of Attention Deficit Disorder with Hyperactivity (ADHD) and exogenous obesity.

Definition

ChEBI: A member of the class of amphetamines in which the amino group of (S)-amphetamine carries a methyl substituent.

Manufacturing Process

2 Methods of prepearing of methamphetamine:
1. (-)-Ephedrin was reduced by hydrogenesation with hydrogen in the presence of Pt-C catalyst to give the (+)-N-α-dimethylphenethylamine (methamphetamine), melting point 172°-174°C.
2. Methamphetamine was obtained by the methylation of phenylisopropylamine.
To give methamphetamine hydrochloride the base methamphetamine was treated by eqimolar quantity of hydrochloric acid.

brand name

Amone;Desoxyn;Dexophrine;Dexoval;Doxyfed;Doxyn Drinalfa;Efroxine;Euphrodinal;Gardstat;Gerobit;Geronyl;Lemobese;Madrine;Mediatric;Meloda;Metamsustac;Methampex;Methedrinal;Neodrine-triple;Obedrin-la;Obelones;Obe-slim;Pervitin;Phedrisox;Phelantin;Philopon;Soxympamine;Syndrox;Tonedron;Uno.

Therapeutic Function

Sympathomimetic, Central stimulant

World Health Organization (WHO)

Metamfetamine, an amfetamine derivative, is controlled under Schedule II of the 1971 Convention on Psychotropic Substances. See WHO comment for amfetamine. (Reference: (UNCPS2) United Nations Convention on Psychotropic Substances (II), , , 1971)

Pharmacokinetics

Methamphetamine is a potent central nervous system stimulant which affects neurochemical mechanisms responsible for regulating heart rate, body temperature, blood pressure, appetite, attention, mood and responses associated with alertness or alarm conditions. The acute effects of the drug closely resemble the physiological and psychological effects of an epinephrine-provoked fight-or-flight response, including increased heart rate and blood pressure, vasoconstriction (constriction of the arterial walls), bronchodilation, and hyperglycemia (increased blood sugar). Users experience an increase in focus, increased mental alertness, and the elimination of fatigue, as well as a decrease in appetite.

Metabolism

Hepatic. The primary site of metabolism is in the liver by aromatic hydroxylation, N-dealkylation and deamination. At least seven metabolites have been identified in the urine, with the main metabolites being amphetamine (active) and 4-hydroxymethamphetamine. Other minor metabolites include 4-hydroxyamphetamine, norephedrine, and 4-hydroxynorephedrine.