Neostigmine is a cholinesterase inhibitor used in the treatment of myasthenia gravis and to reverse the effects of muscle relaxants such as gallamine and tubocurarine. Neostigmine, unlike physostigmine, does not cross the blood-brain barrier. By inhibiting acetylcholinesterase, more acetylcholine is available in the synapse, therefore, more of it can bind to the fewer receptors present in myasthenia gravis and can better trigger muscular contraction. Neostigmine is used for the symptomatic treatment of myasthenia gravis by improving muscle tone.

Butalbital, 5-allyl-5-isobutylbarbituric acid, is a barbiturate with an intermediate duration of action. The different combinations with butalbital is approved. One of them is fioricet with codeine (butalbital, ccetaminophen, caffeine, and codeine phosphate) which is indicated for the relief of the symptom complex of tension (or muscle contraction) headache. Evidence supporting the efficacy and safety of fioricet with codeine in the treatment of multiple recurrent headaches is unavailable. Butalbital is well absorbed from the gastrointestinal tract and is expected to distribute to most tissues in the body. This compound in general may appear in breast milk and readily cross the placental barrier. Monoamine oxidase (MAO) inhibitors may enhance the CNS effects. The mechanism of action for butalbital is proposed the following: this compound 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.

Carbon dioxide is a colorless gas occurring naturally in Earth's atmosphere. Carbon dioxide is a primary carbon source for life on Earth. It is produced by all aerobic organisms during metabolism of carbohydrates and lipids. Carbon dioxide is used in food industry as an acidity regulator and for production of carbonated soft drinks and soda water. In medicine, carbon dioxide is commonly used as an insufflation gas for minimally invasive surgery (laparoscopy, endoscopy, and arthroscopy) to enlarge and stabilize body cavities to provide better visibility of the surgical area. A mixture of carbon dioxide and oxygen is used for stimulation of breathing after apnea, in anesthetic procedures to increase the depth of respiration, to facilitate blind intubations in anesthetic practice.

Cholecalciferol (/ˌkoʊləkælˈsɪfərɒl/) (vitamin D3) is one of the five forms of vitamin D. Cholecalciferol is a steroid hormone that has long been known for its important role in regulating body levels of calcium and phosphorus, in mineralization of bone, and for the assimilation of Vitamin A. The classical manifestation of vitamin D deficiency is rickets, which is seen in children and results in bony deformities including bowed long bones. Most people meet at least some of their vitamin D needs through exposure to sunlight. Ultraviolet (UV) B radiation with a wavelength of 290–320 nanometers penetrates uncovered skin and converts cutaneous 7-dehydrocholesterol to previtamin D3, which in turn becomes vitamin D3. In supplements and fortified foods, vitamin D is available in two forms, D2 (ergocalciferol) and D3 (cholecalciferol) that differ chemically only in their side-chain structure. Vitamin D2 is manufactured by the UV irradiation of ergosterol in yeast, and vitamin D3 is manufactured by the irradiation of 7-dehydrocholesterol from lanolin and the chemical conversion of cholesterol. The two forms have traditionally been regarded as equivalent based on their ability to cure rickets and, indeed, most steps involved in the metabolism and actions of vitamin D2 and vitamin D3 are identical. Both forms (as well as vitamin D in foods and from cutaneous synthesis) effectively raise serum 25(OH) D levels. Firm conclusions about any different effects of these two forms of vitamin D cannot be drawn. However, it appears that at nutritional doses, vitamins D2 and D3 are equivalent, but at high doses, vitamin D2 is less potent. The American Academy of Pediatrics (AAP) recommends that exclusively and partially breastfed infants receive supplements of 400 IU/day of vitamin D shortly after birth and continue to receive these supplements until they are weaned and consume ≥1,000 mL/day of vitamin D-fortified formula or whole milk. Cholecalciferol is used in diet supplementary to treat Vitamin D Deficiency. Cholecalciferol is inactive: it is converted to its active form by two hydroxylations: the first in the liver, the second in the kidney, to form calcitriol, whose action is mediated by the vitamin D receptor, a nuclear receptor which regulates the synthesis of hundreds of enzymes and is present in virtually every cell in the body. Calcitriol increases the serum calcium concentrations by increasing GI absorption of phosphorus and calcium, increasing osteoclastic resorption, and increasing distal renal tubular reabsorption of calcium. Calcitriol appears to promote intestinal absorption of calcium through binding to the vitamin D receptor in the mucosal cytoplasm of the intestine. Subsequently, calcium is absorbed through formation of a calcium-binding protein.

Nitrite Ion is a symmetric anion with equal N–O bond lengths. Nitrite is important in biochemistry as a source of the potent vasodilator nitric oxide. Nitrate or nitrite (ingested) under conditions that result in endogenous nitrosation has been classified as "Probably carcinogenic to humans" (Group 2A) by International Agency for Research on Cancer (IARC), the specialized cancer agency of the World Health Organization (WHO) of the United Nations. Sodium nitrite is used for the curing of meat because it prevents bacterial growth and, as it is a reducing agent (opposite of oxidation agent), in a reaction with the meat's myoglobin, gives the product a desirable pink-red "fresh" color, such as with corned beef. This use of nitrite goes back to the Middle Ages, and in the US has been formally used since 1925. Because of the relatively high toxicity of nitrite (the lethal dose in humans is about 22 milligrams per kilogram of body weight), the maximum allowed nitrite concentration in meat products is 200 ppm. At these levels, some 80 to 90% of the nitrite in the average U.S. diet is not from cured meat products, but from natural nitrite production from vegetable nitrate intake. Under certain conditions – especially during cooking – nitrites in meat can react with degradation products of amino acids, forming nitrosamines, which are known carcinogens. However, the role of nitrites (and to some extent nitrates) in preventing botulism by preventing C. botulinum endospores from germinating have prevented the complete removal of nitrites from cured meat, and indeed by definition in the U.S., meat cannot be labeled as "cured" without nitrite addition. They are considered irreplaceable in the prevention of botulinum poisoning from consumption of cured dry sausages by preventing spore germination. Nitrite is a member of the drug class antidotes and is used to treat Cyanide Poisoning.

Methylene blue, also known as methylthioninium chloride, is a medication from WHO's list of essential medicines. Upon administration, methylene blue is converted to leukomethylene blue by erythrocyte methemoblobin reductase in the presence of NADPH. Leukomethylene blue than reduces methemoglobin to oxyhemoglobin, thus restoring oxygen carrying capacity of the blood. Methylene blue is also used as a dye for various diagnostic procedures, for treatment of ifosfamide toxicity and for in vitro staining. Historically, it was used as a photosensitizer for photodynamic therapy for topical treatment of dermatologic or mucocutaneous infections, as an antidote for cyanide poisoning, but these applications are no longer approved. Methylene blue is investigated in clinical trials for treatment of septic shock and Alzheimer's disease.

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.

Sodium thiosulfate (sodium thiosulphate/STS) is a chemical and medication. As a medication, it is used in combination with sodium nitrite under the trade name to NITHIODOTE treat cyanide poisoning. The primary route of endogenous cyanide detoxification is by enzymatic transulfuration to thiocyanate (SCN- ), which is relatively nontoxic and readily excreted in the urine. Sodium thiosulfate is thought to serve as a sulfur donor in the reaction catalyzed by the enzyme rhodanese, thus enhancing the endogenous detoxification of cyanide. In addition, Sodium thiosulfate is used in calciphylaxis in hemodialysis patients with end-stage kidney disease. Calciphylaxis is vasculopathy characterized by ischemia and painful skin necrosis due to calcification and intimal fibroplasia of thrombosis of the panicular arterioles. Sodium thiosulfate is used as treatment due to its antioxidant activity and as a chelating. Sodium thiosulfate renders renal protection by modulating the mitochondrial KATP channel for preventing urolithiasis. Moreover, STS was assumed to play a vital role in on ischemia reperfusion injury (IR). The effectiveness of STS as a cardioprotective agent was attributed to the reduction of apoptosis by binding to the active site of caspase-3 in silico, which was substantiated by the reduced expression of caspase-3 and poly ADP ribose polymerase levels.

Colchicine is an alkaloid obtained from the plant colchicum autumnale (also known as "meadow saffron"). Colchicine is an alternative medication for those unable to tolerate NSAIDs in gout. Mechanism of action of colchicine is inhibition of microtubule polymerization by binding to tubulin. Availability of tubulin is essential to mitosis, so colchicine effectively unctions as a "mitotic poison" or spindle poison.