Mephentermine, an amphetamine-derived phenethylamine, is an alpha 1 adrenergic receptor agonist and a hypertensive drug. Mephentermine is mainly used as a vasopressor agent with a sympathomimetic action, primarily causing release of noradrenaline and increasing cardiac output due to positive inotropic effect on the myocardium. The injectable preparation of mephentermine is commonly used for the short-term treatment of various hypotensive states such as shock or hypotension accompanying myocardial infarction or spinal anesthesia or surgical procedures like cesarean section. There is evidence on the fetal metabolic effect and placental transfer of mephentermine. However, a few studies have shown that mephentermine is as effective as phenylephrine in preventing maternal hypotension after spinal anesthesia and has similar effect on neonatal outcome. It is being widely used in developing countries like India as it is much more economical than phenylephrine and offers ease of use as it does not necessitate multiple dilutions as injectable. It is also available in India as 10 mg oral tablets. Despite it was thought earlier to have a little stimulant effect its abuse potential has increased, especially in sports due to its stimulant properties. Like amphetamines, it has shown to increase athletic performance in strength exercises and endurance in a dose of 14 mg/70 kg body weight. It has been proposed that phentermine, which is the main metabolite of mephentermine, acts by inhibiting monoaminoxidases A and B. Mephentermine adverse effects has been related to CNS simulation, excessive rises in blood pressure, and arrhythmias. Wyamine Sulfate (brand name of mephentermine sulfate) approved by FDA in 1951 was discontinued in USA.

Mephenytoin is an antiepileptic drug which can be useful in the treatment of epilepsy. The primary site of action appears to be the motor cortex where spread of seizure activity is inhibited. Possibly by promoting sodium efflux from neurons, mephenytoin tends to stabilize the threshold against hyperexcitability caused by excessive stimulation or environmental changes capable of reducing membrane sodium gradient. This includes the reduction of posttetanic potentiation at synapses. Loss of posttetanic potentiation prevents cortical seizure foci from detonating adjacent cortical areas. Mephenytoin reduces the maximal activity of brain stem centers responsible for the tonic phase of tonic-clonic (grand mal) seizures. The mechanism of action of mephenytoin is not definitely known, but extensive research strongly suggests that its main mechanism is to block frequency-, use- and voltage-dependent neuronal sodium channels, and therefore limit repetitive firing of action potentials. Mephenytoin is no longer available in the US or the UK. It is still studied largely because of its interesting hydroxylation polymorphism.

Barbiturates are non-selective depressants of the central nervous system. Butabarbital is one of them, which is used under brand name butisol sodium as a sedative or hypnotic. Like other barbiturates, butabarbital is capable of producing all levels of CNS mood alteration from excitation to mild sedation, to hypnosis, and deep coma. The mechanism of action by which barbiturates exert their effect is not yet completely understood, but is assumed, that butabarbital binds at a distinct binding site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Glutamic acid is a non-essential aminoacid used in biosynthesis of proteins. Besides being a building block of proteins, glutamic acid plays a principal role in neural activation. Glutamate is also responsible for the umami (savory) flavor of certain foods. In medicine, glutamate is used as a metabolic supplemnet in patients undergoing coronary surgery.

Hydroxyamphetamine is a derivative of amphetamines. Hydroxyamphetamine is intended mainly as local eye drops for diagnostic purposes. It is indirect sympathomimetic agent which cause dilation of the eye pupil before diagnostic test. Among the minor side effects from its use are: change in color vision, difficulty seeing at night, dry mouth, headache, increased sensitivity of eyes to sunlight, muscle stiffness or tightness and temporary stinging in the eyes. The main use of hydroxyamphetamines as eye drops is the diagnosis of Horner's syndrome which is characterized by nerve lesions. Hydroxyamphetamine hydrobromide is a component of FDA approved brand drug - Paremyd sterile ophthalmic solution (Hydroxyamphetamine hydrobromide, USP 1.0%, Tropicamide, USP 0.25%). Hydroxyamphetamine is an indirect-acting sympathomimetic, while tropicamide acts as a parasympatholytic.

2,4-dinitrophenol (DNP) is a FDA-banned weight-loss agent and EPA-regulated environmental toxicant, traditionally used in research labs as an uncoupler of OXPHOS. Although not licensed for human consumption, DNP and DNP crystal form are used by bodybuilders and extreme dieters for their fat burning properties through inhibiting efficient energy (ATP) production in cells. Through uncoupling mitochondrial oxidative phosphorylation by facilitating proton transport across the mitochondrial membrane, DNP leads to rapid consumption of energy without generating ATP and consequently, to increased fat metabolism. However, the weight-loss effect comes with serious, and in some cases potentially fatal, adverse side effects, namely hyperthermia (the leading cause of fatality with acute DNP toxicity) and cardiac arrest, but also diaphoresis, tachycardia, tachypnea, skin toxicity, Fourier’s gangrene and cataracts with low dose chronic exposure. The proposed mechanism of DNP induced toxicity suggests the activation of ATP-sensitive K channels.

Hexobarbital or hexobarbitone, (sold both in acid and sodium salt, brand name Evipan, and Tobinal), is a barbiturate derivative having hypnotic and sedative effects. It was used in the 1940s and 1950s as an agent for inducing anesthesia for surgery, as well as a rapid-acting, short-lasting hypnotic for general use, and has a relatively fast onset of effects and short duration of action. It was also used to murder women prisoners at Ravensbruck Concentration Camp. Modern barbiturates (such as Thiopental) has largely supplanted the use of hexobarbital as an anesthetic, as they allow for better control of the depth of anesthesia. Hexobarbital is still used in some scientific research. Hexobarbital binds at a distinct binding site associated with a Cl- ionophore at the GABA-A receptor, increasing the duration of time for which the Cl- ionophore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

Secobarbital sodium, a barbiturate, is FDA approved for the treatment of insomnia and for pre-anesthetic use. This drug binds at a distinct site associated with a Cl- ionopore at the GABAA receptor, increasing the duration of time for which the Cl- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. Adverse reactions are drowsiness, lethargy, hangover, paradoxical excitement in elderly patients, somnolence. Rifampin may decrease secobarbital levels by increasing metabolism.

Pentetrazol (pentylenetetrazole, BTD-001) is a pharmaceutical agent that displays activity as a central nervous system and respiratory stimulant. It is considered a non-competitive gamma-aminobutyric acid (GABA) antagonist. Pentetrazol (pentylenetetrazole) has been used experimentally to study seizure phenomenon and to identify pharmaceuticals that may control seizure susceptibility. GABA is thought to play a role in promoting sleep and its function is believed to be elevated in idiopathic hypersomnia. By blocking GABA’s function, pentetrazol (pentylenetetrazole, BTD-001) is expected to reduce excessive daytime sleepiness.

AMOBARBITAL is a barbiturate derivative with hypnotic and sedative properties. In an in vitro study in rat thalamic slices amobarbital worked by activating GABAA receptors, which decreased input resistance, depressed burst and tonic firing, especially in ventrobasal and intralaminar neurons, while at the same time increasing burst duration and mean conductance at individual chloride channels; this increased both the amplitude and decay time of inhibitory postsynaptic currents. Adverse effects are mainly a consequence of dose-related CNS depression and the risk of dependence with continued use is high.