Allopurinol is a xanthine oxidase inhibitor used to decrease high blood uric acid levels. Allopurinol is specifically used to prevent gout, prevent specific types of kidney stones, and for the high uric acid levels that can occur with chemotherapy. Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation. Allopurinol is a structural analog of the natural purine base, hypoxanthine. It is an inhibitor of xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and of xanthine to uric acid, the end product of purine metabolism in man. Allopurinol is metabolized to the corresponding xanthine analog, oxypurinol (Allopurinol), which also is an inhibitor of xanthine oxidase. Allopurinol is taken by mouth or injected into a vein. Common side effects, when used by mouth, include itchiness and rash. Common side effects when used by injection include vomiting and kidney problems.

Indometacin (INN and BAN) or indomethacin (AAN, USAN, and former BAN) is a nonsteroidal anti-inflammatory drug (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation. Indomethacin has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of Indometacin, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2). Indomethacin is a potent inhibitor of prostaglandin synthesis in vitro. Indomethacin concentrations reached during therapy have produced in vivo effects. Prostaglandins sensitize afferent nerves and potentiate the action of bradykinin in inducing pain in animal models. Prostaglandins are mediators of inflammation. Because indomethacin is an inhibitor of prostaglandin synthesis, its mode of action may be due to a decrease of prostaglandins in peripheral tissues. Indometacin is indicated for: Moderate to severe rheumatoid arthritis including acute flares of chronic disease, Moderate to severe ankylosing spondylitis, Moderate to severe osteoarthritis, Acute painful shoulder (bursitis and/or tendinitis), Acute gouty arthritis. In general, adverse effects seen with indomethacin are similar to all other NSAIDs. For instance, indometacin inhibits both cyclooxygenase-1 and cyclooxygenase-2, it inhibits the production of prostaglandins in the stomach and intestines, which maintain the mucous lining of the gastrointestinal tract. Indometacin, therefore, like other non-selective COX inhibitors can cause peptic ulcers. These ulcers can result in serious bleeding and/or perforation requiring hospitalization of the patient. To reduce the possibility of peptic ulcers, indomethacin should be prescribed at the lowest dosage needed to achieve a therapeutic effect, usually between 50–200 mg/day. It should always be taken with food. Nearly all patients benefit from an ulcer protective drug (e.g. highly dosed antacids, ranitidine 150 mg at bedtime, or omeprazole 20 mg at bedtime). Other common gastrointestinal complaints, including dyspepsia, heartburn and mild diarrhea are less serious and rarely require discontinuation of indomethacin.

Dactinomycin (actinomycin D) was isolated from Streptomyces by Selman Waksman in 1940s. The antibiotic shows anti-cancer activity; it was approved by FDA for the treatment of different cancer conditions among which are Ewing's sarcoma, Wilm's tumor, gestational trophoblastic disease, etc. Dactinomycin exerts its action by binding to DNA (preferably to GC motif) and thus inhibiting transcription.

Valproic acid (VPA; valproate; di-n-propylacetic acid, DPA; 2-propylpentanoic acid, or 2-propylvaleric acid) was first synthesized in 1882, by Burton. FDA approved valproic acid for the treatment of manic episodes associated with bipolar disorder, for the monotherapy and adjunctive therapy of complex partial seizures and simple and complex absence seizures and adjunctive therapy in patients with multiple seizure types that include absence seizures and for the prophylaxis of migraine headaches. The mechanisms of VPA which seem to be of clinical importance in the treatment of epilepsy include increased gamma-aminobutyric acid (GABA)-ergic activity, reduction in excitatory neurotransmission, and modification of monoamines. Recently, it was discovered that the VPA is a class I selective histone deacetylase inhibitor. This activity can be distinguished from its therapeutically exploited antiepileptic activity.

Acetylcysteine (also known as N-acetylcysteine or N-acetyl-L-cysteine or NAC) is primarily used as a mucolytic agent and in the management of acetaminophen poisoning. Acetylcysteine likely protects the liver by maintaining or restoring the glutathione levels, or by acting as an alternate substrate for conjugation with, and thus detoxification of, the reactive metabolite. Nacystelyn (NAL), a recently-developed lysine salt of N-acetylcysteine (NAC) is known to have excellent mucolytic capabilities and is used to treat cystic fibrosis (CF) lung disease. NAC as a precursor to the antioxidant glutathione modulates glutamatergic, neurotrophic, and inflammatory pathways. The potential applications of NAC to facilitate recovery after traumatic brain injury, cerebral ischemia, and in treatment of cerebrovascular vasospasm after subarachnoid hemorrhage. Acetylcysteine serves as a prodrug to L-cysteine, which is a precursor to the biologic antioxidant, glutathione, and hence administration of acetylcysteine replenishes glutathione stores. L-cysteine also serves as a precursor to cystine, which in turn serves as a substrate for the cystine-glutamate antiporter on astrocytes hence increasing glutamate release into the extracellular space. Acetylcysteine also possesses some anti-inflammatory effects possibly via inhibiting NF-κB through redox activation of the nuclear factor kappa kinases thereby modulating cytokine synthesis. NAC is associated with reduced levels of inflammatory cytokines and acts as a substrate for glutathione synthesis. These actions are believed to converge upon mechanisms promoting cell survival and growth factor synthesis, leading to increased neurite sprouting.

Metronidazole was synthesized by France's Rhone-Poulenc laboratories and introduced in the mid-1950s under the brand name Flagel in the US, while Sanofi-Aventis markets metronidazole globally under the same trade name, Flagyl, and also by various generic manufacturers. Metronidazole is one of the rare examples of a drug developed as ant parasitic, which has since gained broad use as an antibacterial agent. Metronidazole, a nitroimidazole, exerts antibacterial effects in an anaerobic environment against most obligate anaerobes. Metronidazole is indicated for the treatment of the following infections due to susceptible strains of sensitive organisms: Trichomoniasis: symptomatic, asymptomatic, asymptomatic consorts; Amebiasis: acute intestinal amebiasis (amebic dysentery) and amebic liver abscess; Anaerobic bacterial infections; Intra-abdominal infections, including peritonitis, intra-abdominal abscess, and liver abscess; Skin and skin structure infections; Gynecologic infections, including endometritis, endomyometritis, tubo-ovarian abscess, and postsurgical vaginal cuff infection; Bacterial septicemia; Bone and joint infections, as adjunctive therapy; Central Nervous System infections, including meningitis and brain abscess; Lower Respiratory Tract infections, including pneumonia, empyema, and lung abscess; Endocarditis. Metronidazole is NOT effective for infections caused by aerobic bacteria that can survive in the presence of oxygen. Metronidazole is only effective against anaerobic bacterial infections because the presence of oxygen will inhibit the nitrogen-reduction process that is crucial to the drug's mechanism of action. Once metronidazole enters the organism by passive diffusion and activated in the cytoplasm of susceptible anaerobic bacteria, it is reduced; this process includes intracellular electron transport proteins such as ferredoxin, transfer of an electron to the nitro group of the metronidazole, and formation of a short-lived nitroso free radical. Because of this alteration of the metronidazole molecule, a concentration gradient is created and maintained which promotes the drug’s intracellular transport. The reduced form of metronidazole and free radicals can interact with DNA leading to inhibition of DNA synthesis and DNA degradation leading to death of the bacteria. The precise mechanism of action of metronidazole is unknown. Metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment.

Fluorouracil is an antineoplastic anti-metabolite. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances from becoming incorporated into DNA during the "S" phase (of the cell cycle), stopping normal development and division. Fluorouracil blocks an enzyme which converts the cytosine nucleotide into the deoxy derivative. In addition, DNA synthesis is further inhibited because Fluorouracil blocks the incorporation of the thymidine nucleotide into the DNA strand. Fluorouracil is used for the topical treatment of multiple actinic or solar keratoses. In the 5% strength it is also useful in the treatment of superficial basal cell carcinomas when conventional methods are impractical, such as with multiple lesions or difficult treatment sites. Fluorouracil injection is indicated in the palliative management of some types of cancer, including colon, esophageal, gastric, rectum, breast, biliary tract, stomach, head and neck, cervical, pancreas, renal cell, and carcinoid.

Iothalamic Acid is an iodine-containing organic anion used as a radiocontrast agent. It is available as sodium iothalamate (Iothalamate sodium) and meglumine iothalamate (Iothalmate meglumine). It can be administered intravenously or intravesically (into the urinary bladder). Iothalamate is indicated to visualize specific regions of the vascular system and blood flow in these areas to help in the diagnosis and evaluation of neoplasms (known or suspected) or vascular diseases (congenital or acquired) that may cause changes in normal vascular anatomy or physiology. Iothalamate meglumine injection is indicated for use in cerebral angiography, peripheral arteriography or venography, arterial digital subtraction angiography1 , and intravenous digital subtraction angiography. Iothalamate meglumine and iothalamate sodium injection is indicated for use in selective coronary arteriography, selective renal arteriography, and in intravenous digital subtraction angiography. othalamate meglumine and iothalamate sodium injection and iothalamate sodium injection are indicated to visualize the aorta and its major branches. However, the injection of iothalamate meglumine and iothalamate sodium is preferred because it generally causes less severe hemodynamic, neurotoxic, and cardiotoxic effects than the individual injection of iothalamate sodium. Radioactive formulation is also available as sodium iothalamate I-125 Injection (GLOFIL-125). It is indicated for evaluation of glomerular filtration in the diagnosis or monitoring of patients with renal disease.

A centrally acting skeletal muscle relaxant whose mechanism of action is not completely understood but may be related to its sedative actions. Carisoprodol is indicated for the relief of discomfort associated with acute, painful musculoskeletal conditions in adults. Most common adverse reactions (incidence > 2%) are drowsiness, dizziness, and headache. Carisoprodol might be mixtured with Aspirin and Codeine Phosphate. Studies indicating increased risk of abuse or addiction led to withdrawal of the drug from the market in Norway and other EU countries in 2008.

Methocarbamol is a central muscle relaxant for skeletal muscles, used to treat spasms. It is structurally related to guaifenesin. Methocarbamol's exact mechanism of causing skeletal muscle relaxation is unknown. It is thought to work centrally, perhaps by general depressant effects. It has no direct relaxant effects on striated muscle, nerve fibers, or the motor endplate. It will not directly relax contracted skeletal muscles. The drug has a secondary sedative effect. Methocarbamol is used for use as an adjunct to rest, physical therapy, and other measures for the relief of discomforts associated with acute, painful musculoskeletal conditions. Under the trade name Robaxin, Methocarbamol is marketed by Actient Pharmaceuticals in the United States and Pfizer in Canada.