Doxapram is an analeptic agent (a stimulant of the central nervous system). The respiratory stimulant action is manifested by an increase in tidal volume associated with a slight increase in respiratory rate. A pressor response may result following doxapram administration. Provided there is no impairment of cardiac function, the pressor effect is more marked in hypovolemic than in normovolemic states. The pressor response is due to the improved cardiac output rather than peripheral vasoconstriction. Following doxapram administration, an increased release of catecholamines has been noted. Doxapram produces respiratory stimulation mediated through the peripheral carotid chemoreceptors. It is thought to stimulate the carotid body by inhibiting certain potassium channels. Used as temporary measure in hospitalized patients with acute respiratory insufficiency superimposed on chronic obstructive pulmonary disease.

Thioridazine (Mellaril or Melleril) is a piperidine typical antipsychotic drug belonging to the phenothiazine drug group and was previously widely used in the treatment of schizophrenia and psychosis. Thioridazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; blocks alpha-adrenergic effect depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. Thioridazine primary use in medicine was the treatment of schizophrenia. Thioridazine was also tried with some success as a treatment for various psychiatric symptoms seen in people with dementia, but chronic use of thioridazine and other antipsychotics in people with dementia is not recommended. Thioridazine prolongs the QTc interval in a dose-dependent manner. It produces significantly less extrapyramidal side effects than most first-generation antipsychotics. Its use, along with the use of other typical antipsychotics, has been associated with degenerative retinopathies. It has a higher propensity for causing anticholinergic side effects coupled with a lower propensity for causing extrapyramidal side effects and sedation than chlorpromazine but also has a higher incidence of hypotension and cardiotoxicity. It is also known to possess a relatively high liability for causing orthostatic hypotension compared to other antipsychotics. Similarly to other first-generation antipsychotics, it has a relatively high liability for causing prolactin elevation. It is the moderate risk of causing weight gain.

Ethosuximide is a succinimide anticonvulsant, used in the treatment of epilepsy. Ethosuximide suppresses the paroxysmal three cycle per second spike and wave activity associated with lapses of consciousness which is common in absence (petit mal) seizures. The frequency of epileptiform attacks is reduced, apparently by depression of the motor cortex and elevation of the threshold of the central nervous system to convulsive stimuli. Binds to T-type voltage sensitive calcium channels. Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1G gives rise to T-type calcium currents. T-type calcium channels belong to the "low-voltage activated (LVA)" group and are strongly blocked by mibefradil. A particularity of this type of channels is an opening at quite negative potentials and a voltage-dependent inactivation. T-type channels serve pacemaking functions in both central neurons and cardiac nodal cells and support calcium signaling in secretory cells and vascular smooth muscle. They may also be involved in the modulation of firing patterns of neurons which is important for information processing as well as in cell growth processes. Ethosuximide is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.

Diphenoxylate is an opioid drug used for the treatment of acute diarrhea. The drug is used in combination with atropine and marketed under names Lomotil and Diphenoxylate hydrochloride and atropine sulfate. Diphenoxylate is biotransformed in man by ester hydrolysis to diphenoxylic acid (difenoxine), which is biologically active and the major metabolite in the blood. The drug exerts its action by activating mu opioid receptors of intestinal mucosa.

Tropicamide (Mydriacyl) is an anticholinergic used as a mydriatic.Tropicamide belongs to the group of medicines called anti-muscarinics. Tropicamide blocks the receptors in the muscles of the eye (muscarinic receptors). These receptors are involved controlling the pupil size and the shape of the lens. By blocking these receptors, tropicamide produces dilatation of the pupil (mydriasis) and prevents the eye from accommodating for near vision (cycloplegia). Tropicamide is given as eye drops to dilate the pupil and relax the lens so that eye examinations can be carried out thoroughly.

Hydroxyzine, a piperazine antihistamine structurally related to buclizine, cyclizine, and meclizine, is used to treat histamine-mediated pruritus or pruritus due to allergy, nausea and vomiting, and, in combination with an opiate agonist, anxiolytic pain. Hydroxyzine is also used as a perioperative sedative and anxiolytic and to manage acute alcohol withdrawal. Hydroxyzine competes with histamine for binding at H1-receptor sites on the effector cell surface, resulting in suppression of histaminic edema, flare, and pruritus. The sedative properties of hydroxyzine occur at the subcortical level of the CNS. Secondary to its central anticholinergic actions, hydroxyzine may be effective as an antiemetic. It is used for symptomatic relief of anxiety and tension associated with psychoneurosis and as an adjunct in organic disease states in which anxiety is manifested.

Hydroxychloroquine possesses antimalarial properties and also exerts a beneficial effect in lupus erythematosus (chronic discoid or systemic) and acute or chronic rheumatoid arthritis. Although the exact mechanism of action is unknown, it may be based on ability of hydroxychloroquine to bind to and alter DNA. Hydroxychloroquine has also has been found to be taken up into the acidic food vacuoles of the parasite in the erythrocyte. This increases the pH of the acid vesicles, interfering with vesicle functions and possibly inhibiting phospholipid metabolism. In suppressive treatment, hydroxychloroquine inhibits the erythrocytic stage of development of plasmodia. In acute attacks of malaria, it interrupts erythrocytic schizogony of the parasite. Its ability to concentrate in parasitized erythrocytes may account for their selective toxicity against the erythrocytic stages of plasmodial infection. As an antirheumatic, hydroxychloroquine is thought to act as a mild immunosuppressant, inhibiting the production of rheumatoid factor and acute phase reactants. It also accumulates in white blood cells, stabilizing lysosomal membranes and inhibiting the activity of many enzymes, including collagenase and the proteases that cause cartilage breakdown. Hydroxychloroquine is used for the suppressive treatment and treatment of acute attacks of malaria due to Plasmodium vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum. It is also indicated for the treatment of discoid and systemic lupus erythematosus, and rheumatoid arthritis.

Chloroprocaine (Nesacaine®, Nesacaine®-MPF) is a non pyrogenic local anesthetic. Nesacaine® is indicated for the production of local anesthesia by infiltration and peripheral nerve block. It is not to be used for lumbar or caudal epidural anesthesia. Nesacaine®-MPF is indicated for the production of local anesthesia by infiltration, peripheral and central nerve block, including lumbar and caudal epidural blocks. Nesacaine® and Nesacaine®-MPF are not to be used for subarachnoid administration. Chloroprocaine (Nesacaine®, Nesacaine®-MPF), like other local anesthetics, blocks the generation and the conduction of nerve impulses, presumably by increasing the threshold for electrical excitation in the nerve, by slowing the propagation of the nerve impulse and by reducing the rate of rise of the action potential. It acts mainly by inhibiting sodium influx through voltage gated sodium channels in the neuronal cell membrane of peripheral nerves. When the influx of sodium is interrupted, an action potential cannot arise and signal conduction is thus inhibited.

Proparacaine is a topical anesthetic drug of the amino ester group. It is available as its hydrochloride salt in ophthalmic solutions at a concentration of 0.5%. Proparacaine hydrochloride ophthalmic solution is indicated for procedures in which a topical ophthalmic anesthetic is indicated: corneal anesthesia of short duration, e.g. tonometry, gonioscopy, removal of corneal foreign bodies, and for short corneal and conjunctival procedures. Proparacaine stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby effecting local anesthetic action. More specifically, proparacaine appears to bind or antagonize the function of voltage gated sodium channels. The exact mechanism whereby proparacaine and other local anesthetics influence the permeability of the cell membrane is unknown; however, several studies indicate that local anesthetics may limit sodium ion permeability through the lipid layer of the nerve cell membrane. Proparacaine may alter epithelial sodium channels through interaction with channel protein residues. This limitation prevents the fundamental change necessary for the generation of the action potential.

Cyclopentolate (cyclopentolate hydrochloride) is a parasympatholytic anticholinergic used solely to obtain mydriasis or cycloplegia. This anticholinergic preparation blocks the responses of the sphincter muscle of the iris and the accommodative muscle of the ciliary body to cholinergic stimulation, producing pupillary dilation (mydriasis) and paralysis of accommodation (cycloplegia). It acts rapidly, but has a shorter duration than atropine. Maximal cycloplegia occurs within 25 to 75 minutes after instillation. Complete recovery of accommodation usually takes 6 to 24 hours. Complete recovery from mydriasis in some individuals may require several days. Heavily pigmented irides may require more doses than lightly pigmented irides.