Pyrimethamine, sold under the trade name Daraprim, is one of the folic acid antagonists that is used as an antimalarial or with a sulfonamide to treat toxoplasmosis. In addition it was approved in Chemoprophylaxis of Malaria. However, resistance to pyrimethamine is prevalent worldwide. It is not suitable as a prophylactic agent for travelers to most areas. Pyrimethamine is well absorbed with peak levels occurring between 2 to 6 hours following administration. It is eliminated slowly and has a plasma half-life of approximately 96 hours. Pyrimethamine is 87% bound to human plasma proteins. Pyrimethamine acts by selectively inhibiting malarial dihydrofolate reductase-thymidylate synthase and the rationale for its therapeutic action is based on the differential requirement between host and parasite for nucleic acid precursors involved in growth. This activity is highly selective against plasmodia and Toxoplasma gondii. Pyrimethamine possesses blood schizonticidal and some tissue schizonticidal activity against malaria parasites of humans. The action of pyrimethamine against Toxoplasma gondii is greatly enhanced when used in conjunction with sulfonamides.

Riboflavin (vitamin B2) is part of the vitamin B group. Riboflavin 5’-phosphate is the precursor of two coenzymes, flavin adenine dinucleotide and flavin mononucleotide, which catalyze oxidation/reduction reactions involved in a number of metabolic pathways. FAD and riboflavin phosphate in foods are hydrolyzed in the intestinal lumen by nucleotide diphosphatase and a variety of nonspecific phosphatases to yield free riboflavin, which is absorbed in the upper small intestines by a sodium-dependent saturable mechanism. Riboflavin has been used in several clinical and therapeutic situations. For over 30 years, riboflavin supplements have been used as part of the phototherapy treatment of neonatal jaundice. Corneal ectasia is a progressive thinning of the cornea; the most common form of this condition is keratoconus. Collagen cross-linking is a non-surgical treatment intended to slow progression of corneal ectasia by strengthening corneal tissue. The standard protocol calls for application directly to the eye of a 0.1% riboflavin solution for 30 minutes followed by 30 minutes of ultraviolet-A irradiation with a wavelength of 370 nm and power of 3 mW/cm2. Under the conditions used for corneal collagen cross-linking, riboflavin 5‘-phosphate functions as a photo enhancer and generates singlet oxygen which is responsible for the cross-linking.

Primaquine is a oral medication used to treat and prevent malaria and to treat Pneumocystis pneumonia. Specifically it is used for malaria due to Plasmodium vivax and Plasmodium ovale along with other medications and for prevention if other options cannot be used. Primaquine is an alternative treatment for Pneumocystis pneumonia together with clindamycin. Primaquine is lethal to P. vivax and P. ovale in the liver stage, and also to P. vivax in the blood stage through its ability to do oxidative damage to the cell. However, the exact mechanism of action is not fully understood. Primaquine is well-absorbed in the gut and extensively distributed in the body without accumulating in red blood cells. Administration of primaquine with food or grapefruit juice increases its oral bioavailibity. In blood, about 20% of circulating primaquine is protein-bound, with preferential binding to the acute phase protein orosomucoid. With a half-life on the order of 6 hours, it is quickly metabolized by liver enzymes to carboxyprimaquine, which does not have anti-malarial activity. Common side effects of primaquine administration include nausea, vomiting, and stomach cramps. Primaquine phosphate is recommended only for the radical cure of vivax malaria, the prevention of relapse in vivax malaria, or following the termination of chloroquine phosphate suppressive therapy in an area where vivax malaria is endemic. Patients suffering from an attack of vivax malaria or having parasitized red blood cells should receive a course of chloroquine phosphate, which quickly destroys the erythrocytic parasites and terminates the paroxysm. Primaquine phosphate should be administered concurrently in order to eradicate the exoerythrocytic parasites in a dosage of 1 tablet (equivalent to 15 mg base) daily for 14 days.

Oxycodone is a semisynthetic opioid used for the management of acute and chronic pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Oxycodone is a highly selective full agonist of the μ-opioid receptor (MOR), with low affinity for the δ-opioid receptor (DOR) and κ-opioid receptor (KOR). After oxycodone binds to the MOR, a G protein-complex is released, which inhibits the release of neurotransmitters by the cell by reducing the amount of cAMP produced, closing calcium channels, and opening potassium channels. After a dose of conventional (instant-release) oral oxycodone, the onset of action is 10–30 minutes, and peak plasma levels of the drug are attained within roughly 30–60 minutes in contrast, after a dose of OxyContin (an oral controlled-release formulation), peak plasma levels of oxycodone occur in about three hours. The duration of instant-release oxycodone is 3 to 6 hours, although this can be variable depending on the individual. Oxycodone in the blood is distributed to skeletal muscle, liver, intestinal tract, lungs, spleen, and brain. Serious side effects of oxycodone include reduced sensitivity to pain (beyond the pain the drug is taken to reduce), euphoria, anxiolysis, feelings of relaxation, and respiratory depression. Common side effects of oxycodone include constipation (23%), nausea (23%), vomiting (12%), somnolence (23%), dizziness (13%), itching (13%), dry mouth (6%), and sweating (5%).

Hexachlorophene, also known as Nabac, is an organochlorine compound that was once widely used as a disinfectant. The compound occurs as a white odorless solid, although commercial samples can be off-white and possess a slightly phenolic odor. It is insoluble in water but dissolves in acetone, ethanol, diethyl ether, and chloroform. Exact mechanism(s) of action unknown, but at low concentrations appears to interrupt bacterial electron transport and inhibit membrane-bound enzymes. Higher concentrations rupture bacterial membranes. It induces leakage, causes protoplast lysis, and inhibits respiration. In medicine, hexachlorophene is a useful as a topical anti-infective, anti-bacterial agent, often used in soaps and toothpaste. It is also used in agriculture as a soil fungicide, plant bactericide, and acaricide.

Ascorbic acid (vitamin C) is a water-soluble vitamin. It occurs as a white or slightly yellow crystal or powder with a slight acidic taste. Ascorbic acid is an electron donor, and this property accounts for all its known functions. As an electron donor, ascorbic acid is a potent water-soluble antioxidant in humans. Ascorbic acid acts as an antioxidant under physiologic conditions exhibiting a cross over role as a pro-oxidant in pathological conditions. Oxidized ascorbic acid (dehydroascorbic acid (DHA) directly inhibits IkappaBalpha kinase beta (IKKbeta) and IKKalpha enzymatic activity in vitro, whereas ascorbic acid did not have this effect. These findings define a function for vitamin C in signal transduction other than as an antioxidant and mechanistically illuminate how vitamin C down-modulates NF-kappaB signaling. Vitamin C is recommended for the prevention and treatment of scurvy. Its parenteral administration is desirable for patients with an acute deficiency or for those whose absorption of orally ingested ascorbic acid (vitamin c) is uncertain. Symptoms of mild deficiency may include faulty bone and tooth development, gingivitis, bleeding gums, and loosened teeth. Febrile states, chronic illness, and infection (pneumonia, whooping cough, tuberculosis, diphtheria, sinusitis, rheumatic fever, etc.) increase the need for ascorbic acid (vitamin c). Hemovascular disorders, burns, delayed fracture and wound healing are indications for an increase in the daily intake.

Pyridoxine is the 4-methanol form of vitamin B6 and is converted to pyridoxal 5-phosphate in the body. Vitamin B6 (pyridoxine) is a water-soluble vitamin used in the prophylaxis and treatment of vitamin B6 deficiency and peripheral neuropathy in those receiving isoniazid (isonicotinic acid hydrazide, INH). Vitamin B6 has been found to lower systolic and diastolic blood pressure in a small group of subjects with essential hypertension. Hypertension is another risk factor for atherosclerosis and coronary heart disease. Another study showed pyridoxine hydrochloride to inhibit ADP- or epinephrine-induced platelet aggregation and to lower total cholesterol levels and increase HDL-cholesterol levels, again in a small group of subjects. Vitamin B6, in the form of pyridoxal 5'-phosphate, was found to protect vascular endothelial cells in culture from injury by activated platelets. Endothelial injury and dysfunction are critical initiating events in the pathogenesis of atherosclerosis. Human studies have demonstrated that vitamin B6 deficiency affects cellular and humoral responses of the immune system. Vitamin B6 deficiency results in altered lymphocyte differentiation and maturation, reduced delayed-type hypersensitivity (DTH) responses, impaired antibody production, decreased lymphocyte proliferation and decreased interleukin (IL)-2 production, among other immunologic activities. Used for the treatment of vitamin B6 deficiency and for the prophylaxis of isoniazid-induced peripheral neuropathy.

Ergoalcifediol (Vitamin D2) is a fat soluble steroid hormone precursor of vitamin D. The principal biologic function of vitamin D is the maintenance of normal levels of serum calcium and phosphorus in the bloodstream by enhancing the efficacy of the small intestine to absorb these minerals from the diet. Cholecalciferol is synthesized within our bodies naturally, but if UV exposure is inadequate or the metabolism of cholecalciferol is abnormal, then an exogenous source is required. Vitamin D2 is converted to 25-hydroxyvitamin D (25OHD) in the liver, and then to the active form, 1,25-dihydroxyvitamin D (1,25(OH)2D), in the kidney. Once transformed, it binds to the vitamin D receptor, which leads to a variety of regulatory roles. Vitamin D plays an important role in maintaining calcium balance and in the regulation of parathyroid hormone (PTH). It promotes renal reabsorption of calcium, increases intestinal absorption of calcium and phosphorus, and increases calcium and phosphorus mobilization from bone to plasma. Very few foods naturally contain vitamin D. Sources that contain the vitamin include fatty fish, the liver and fat of aquatic mammals (e.g., seals, polar bears), and eggs from chickens fed vitamin D-fortified feed. As such, many countries have instituted policies to fortify certain foods with vitamin D to compensate for the potentially low exposures of skin to sunlight. Vitamin D deficiency results in inadequate mineralization of bone or compensatory skeletal demineralization and causes decreased ionized calcium concentrations in blood and a resultant increase in the production and secretion of PTH. Increase in PTH stimulates the mobilization of skeletal calcium, inhibits renal excretion of calcium, and stimulates renal excretion of phosphorus. This results in normal fasting serum calcium concentrations and low or near-normal serum phosphorus. The enhanced mobilization of skeletal calcium induced by this secondary hyperparathyroidism leads porotic bone. Ergoalcifediol is used for use in the management of hypocalcemia and its clinical manifestations in patients with hypoparathyroidism, as well as for the treatment of familial hypophosphatemia (vitamin D resistant rickets). This drug has also been used in the treatment of nutritional rickets or osteomalacia, vitamin D dependent rickets, rickets or osteomalacia secondary to long-term high dose anticonvulsant therapy, early renal osteodystrophy, osteoporosis (in conjunction with calcium), and hypophosphatemia associated with Fanconi syndrome (with treatment of acidosis). Ergocalciferol is manufactured and marketed under various names, including Deltalin (Eli Lilly and Company), Drisdol (Sanofi-Synthelabo) and Calcidol (Patrin Pharma).

Estradiol an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids. In humans, it is produced primarily by the cyclic ovaries and the placenta. It is also produced by the adipose tissue of men and postmenopausal women. The 17-alpha-isomer of estradiol binds weakly to estrogen receptors (receptors, estrogen) and exhibits little estrogenic activity in estrogen-responsive tissues. Estradiol enters target cells freely (e.g., female organs, breasts, hypothalamus, pituitary) and interacts with a target cell receptor. When the estrogen receptor has bound its ligand it can enter the nucleus of the target cell, and regulate gene transcription which leads to formation of messenger RNA. The mRNA interacts with ribosomes to produce specific proteins that express the effect of estradiol upon the target cell. Estradiol is used for the treatment of urogenital symptoms associated with post-menopausal atrophy of the vagina (such as dryness, burning, pruritus and dyspareunia) and/or the lower urinary tract (urinary urgency and dysuria). Estradiol is marketed under the brand name Climara (among others), indicated for: the treatment of moderate to severe vasomotor symptoms due to menopause, treatment of symptoms of vulvar and vaginal atrophy due to menopause, treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure and prevention of postmenopausal osteoporosis.

Iron(II) gluconate (also known as a ferrous gluconate) is used in the treatment of hypochromic anemia. The real problem of iron therapy is not the theoretical utilization of iron, or the reticulocyte response, or even the daily increase of hemoglobin. These are important only as they indicate the return of the patients' blood to normal in a reasonably short time without undue inconvenience. Most patients suffering from hypochromic anemia respond well to most forms of iron when administered in adequate dosage. For the patients who cannot tolerate the usual iron compounds, it is important to have a medication which is effective and which causes minimum disturbance. Ferrous gluconate is such a medicament.