Dihydro-alpha-ergocryptine is an ergot alkaloid that has an agonist activity on D2 dopaminergic receptors and a partial agonist activity on D1 receptors. It also demonstrated antagonistic activity towards alpha-adrenergic receptors. The drug was approved by FDA in combination with other alkaloids (dihydroergocornine, dihydroergocristine and dihydro-beta-ergocryptine mesylate salts) under the name Hydergine for the treatment of dimentia and cerebrovascular insufficiency.

Amodiaquine is a medication used to treat malaria, including Plasmodium falciparum malaria when uncomplicated. The mechanism of plasmodicidal action of amodiaquine is not completely certain. Like other quinoline derivatives, it is thought to inhibit heme polymerase activity. This results in accumulation of free heme, which is toxic to the parasites. The drug binds the free heme preventing the parasite from converting it to a form less toxic. This drug-heme complex is toxic and disrupts membrane function. The side effects of amodiaquine are generally minor to moderate and are similar to those of chloroquine. Rarely liver problems or low blood cell levels may occur. When taken in excess headaches, trouble seeing, seizures, and cardiac arrest may occur. After oral administration amodiaquine hydrochloride is rapidly absorbed,and undergoes rapid and extensive metabolism to desethylamodiaquine which concentrates in red blood cells. It is likely that desethylamodiaquine, not amodiaquine, is responsible for most of the observed antimalarial activity, and that the toxic effects of amodiaquine after oral administration may in part be due to desethylamodiaquine.

Paramethadione is an anticonvulsant in the oxazolidinedione class developed by the Abbott Laboratories, approved by the Food and Drug Administration in 1949 for the treatment of absence seizures, also called partial seizures. Paramethadione acts to reduce T-type calcium currents in thalamic neurons which has been proposed to underlie the 3-Hz spike-and-wave discharge seen on electroencephalogram (EEG) during absence seizures.

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.

Trimethadione (brand name is TRIDIONE) is an oxazolidinedione compound that was developed as an antiepileptic agent for control of petit mal seizures that are refractory to treatment with other drugs. Tridione does not modify the maximal seizure pattern in patients undergoing electroconvulsive therapy and has a sedative effect that may increase to the point of ataxia when excessive doses are used. Trimethadione acts as a voltage-activated T-type Ca2+ channel blocker. Trimethadione is rapidly absorbed from the gastrointestinal tract. It is demethylated by liver microsomes to the active metabolite, dimethadione. Approximately 3% of a daily dose of tridione is recovered in the urine as the unchanged drug. The majority of trimethadione is excreted slowly by the kidney in the form of dimethadione.

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.

Mephobarbital us a barbiturate derivative used primary as an anticonvulsant, but also as a sedative and anxiolytic. Marketing of mephobarbital was discontinued in 2012.

Aconitine is an alkaloid found in the Aconitum species. Aconitine is a highly toxic cardiotoxin and neurotoxin. In China and other countries, the herbal extract containing aconitine was used for the treatment of pain in musculoskeletal disorders, however the safety margin between therapeutic analgesic effect of aconitine and its known cardiotoxic effect is so narrow that the treatment may cause poisoning and death. The mechanism of aconitine action is explained by its ability to activate voltage-dependent sodium-ion channels.

QUININE HYPOPHOSPHITE, a salt of quinine, was formerly used, along with the hypophosphites of sodium, potassium, calcium, and iron, in the treatment of phthisis and neurasthenic conditions.