Naloxone, sold under the brand name Narcan among others, is a medication used to block the effects of opioids, especially in overdose. Naloxone has an extremely high affinity for μ-opioid receptors in the central nervous system (CNS). Naloxone is a μ-opioid receptor (MOR) inverse agonist, and its rapid blockade of those receptors often produces rapid onset of withdrawal symptoms. Naloxone also has an antagonist action, though with a lower affinity, at κ- (KOR) and δ-opioid receptors (DOR). If administered in the absence of concomitant opioid use, no functional pharmacological activity occurs (except the inability for the body to combat pain naturally). In contrast to direct opiate agonists, which elicit opiate withdrawal symptoms when discontinued in opiate-tolerant people, no evidence indicates the development of tolerance or dependence on naloxone. The mechanism of action is not completely understood, but studies suggest it functions to produce withdrawal symptoms by competing for opiate receptor sites within the CNS (a competitive antagonist, not a direct agonist), thereby preventing the action of both endogenous and xenobiotic opiates on these receptors without directly producing any effects itself. When administered parenterally (e.g. intravenously or by injection), as is most common, naloxone has a rapid distribution throughout the body. The mean serum half-life has been shown to range from 30 to 81 minutes, shorter than the average half-life of some opiates, necessitating repeat dosing if opioid receptors must be stopped from triggering for an extended period. Naloxone is primarily metabolized by the liver. Its major metabolite is naloxone-3-glucuronide, which is excreted in the urine. Naloxone is useful both in acute opioid overdose and in reducing respiratory or mental depression due to opioids. Whether it is useful in those in cardiac arrest due to an opioid overdose is unclear. Naloxone is poorly absorbed when taken by mouth, so it is commonly combined with a number of oral opioid preparations, including buprenorphine and pentazocine, so that when taken orally, just the opioid has an effect, but if misused by injecting, the naloxone blocks the effect of the opioid. In a meta-analysis of people with shock, including septic, cardiogenic, hemorrhagic, or spinal shock, those who received naloxone had improved blood flow. Naloxone is also experimentally used in the treatment for congenital insensitivity to pain with anhidrosis, an extremely rare disorder (one in 125 million) that renders one unable to feel pain or differentiate temperatures. Naloxone can also be used as an antidote in overdose of clonidine, a medication that lowers blood pressure.

Minocycline is a tetracycline analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant staphylococcus infections. Minocycline has many brand names one of them is minocin, Minocin is indicated in the treatment of the following infections due to susceptible isolates of the designated bacteria: Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox and tick fevers caused by rickettsiae. Respiratory tract infections caused by Mycoplasma pneumoniae. Lymphogranuloma venereum caused by Chlamydia trachomatis. Psittacosis (Ornithosis) due to Chlamydophila psittaci etc. Minocycline is indicated for the treatment of infections caused by the following Gram-negative bacteria when bacteriologic testing indicates appropriate susceptibility to the drug: Escherichia coli. Enterobacter aerogenes. Shigella species etc. MINOCIN also is indicated for the treatment of infections caused by the following Gram-positive bacteria when bacteriologic testing indicates appropriate susceptibility to the drug: Upper respiratory tract infections caused by Streptococcus pneumoniae. Skin and skin structure infections caused by Staphylococcus aureus (Note: Minocycline is not the drug of choice in the treatment of any type of staphylococcal infection, etc. When penicillin is contraindicated, minocycline is an alternative drug in the treatment of the following infections: Meningitis due to Neisseria meningitidis. Syphilis caused by Treponema pallidum subspecies pallidum. Yaws caused by Treponema pallidum subspecies pertenue, etc. Minocycline passes directly through the lipid bilayer or passively diffuses through porin channels in the bacterial membrane. Minocycline inhibits protein synthesis by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria.

Flucytosine (5-flucytosine, Ancobon) is an antifungal agent used for treatment of serious fungal infections caused by Candida or Cryptococcus. A fluorinated cytosine analog it was originally developed as an anti-tumor agent, but was found to be non-effective against tumors. Monotherapy with 5-FC is limited because of the frequent development of pathogens resistance. It is often used in in combination with amphotericin B. The severe side effects of 5-flucytosine include hepatotoxicity and bone-marrow depression. 5-fluorocytosine is a prodrug to the cytotoxic compound 5-fluorouracil. Although the exact mode of action is unknown, it has been proposed that flucytosine acts directly on fungal organisms by competitive inhibition of purine and pyrimidine uptake and indirectly by intracellular metabolism to 5-fluorouracil. Flucytosine is taken up by fungal organisms via the enzyme cytosine permease. Inside the fungal cell, flucytosine is rapidly converted to fluorouracil by the enzyme cytosine deaminase. Fluorouracil exerts its antifungal activity through the subsequent conversion into several active metabolites, which inhibit protein synthesis by being falsely incorporated into fungal RNA or interfere with the biosynthesis of fungal DNA through the inhibition of the enzyme thymidylate synthetase.

Alitretinoin, or 9-cis-retinoic acid, is a form of vitamin A. It is also used in medicine as an antineoplastic (anti-cancer) agent developed by Ligand Pharmaceuticals. Alitretinoin (9-cis-retinoic acid) is a naturally-occurring endogenous retinoid indicated for topical treatment of cutaneous lesions in patients with AIDS-related Kaposi's sarcoma. Alitretinoin inhibits the growth of Kaposi's sarcoma (KS) cells in vitro. Alitretinoin binds to and activates all known intracellular retinoid receptor subtypes (RARa, RARb, RARg, RXRa, RXRb and RXRg). Once activated these receptors function as transcription factors that regulate the expression of genes that control the process of cellular differentiation and proliferation in both normal and neoplastic cells. In the United States, topical alitretinoin (in the form of a gel; trade name Panretin) is indicated for the treatment of skin lesions in AIDS-related Kaposi's sarcoma.

Levodopa (L-DOPA) was first isolated from seedlings of Vicia faba by Marcus Guggenheim in 1913. Levodopa, a dopamine precursor, is an effective and well-tolerated dopamine replacement agent used to treat Parkinson's disease. Oral levodopa has been widely used for over 40 years, often in combination with a dopa-decarboxylase inhibitor carbidopa, which reduces many treatment complications, extending its half-life and increasing levodopa availability to the brain. Entacapone, a catechol-O-methyltransferase inhibitor, can also be used to improve the bioavailability of levodopa, especially when used in conjunction with a carbidopa.

Ketamine (brand name Ketalar) is a cyclohexanone derivative used for induction of anesthesia. Ketalar is indicated as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation; also, it is indicated for the induction of anesthesia prior to the administration of other general anesthetic agents. Ketamine blocks NMDA receptors through an interaction with sites thought to be located within the ion channel pore region. However, the complete pharmacology of ketamine is more complex, and it is known to directly interact with a variety of other sites to varying degrees. Recently, it was shown that inclusion of the NR3B subunit does not alter the ketamine sensitivity of recombinant NR1/NR2 receptors expressed in oocytes. Likewise, 100 μM ketamine produced only weak inhibition of the glycine-induced current of NR1/NR3A/NR3B receptors. The side effects of ketamine noted in clinical studies include psychedelic symptoms (hallucinations, memory defects, panic attacks), nausea/vomiting, somnolence, cardiovascular stimulation and, in a minority of patients, hepatoxicity. The recreational use of ketamine is increasing and comes with a variety of additional risks ranging from bladder and renal complications to persistent psychotypical behaviour and memory defects. Ketamine was first synthesized in 1962 by Calvin Stevens at Parke-Davis Co (now Pfizer) as an alternative anesthetic to phencyclidine. It was first used in humans in 1965 by Corssen and Domino and was introduced into clinical practice by 1970.

Clindamycin hydrochloride is the hydrated hydrochloride salt of clindamycin. Clindamycin is a semisynthetic antibiotic produced by a 7(S)-chloro-substitution of the 7(R)-hydroxyl group of the parent compound lincomycin. Clindamycin inhibits bacterial protein synthesis by binding to the 50S subunit of the ribosome. It has activity against Gram-positive aerobes and anaerobes as well as some Gram-negative anaerobes.

Mitotane is an oral chemotherapeutic agent indicated in the treatment of inoperable adrenal cortical carcinoma of both functional and nonfunctional types. Mitotane can best be described as an adrenal cytotoxic agent, although it can cause adrenal inhibition, apparently without cellular destruction. The administration of Mitotane alters the extra-adrenal metabolism of cortisol in man; leading to a reduction in measurable 17-hydroxy corticosteroids, even though plasma levels of corticosteroids do not fall. The drug apparently causes increased formation of 6-B-hydroxyl cortisol. Its biochemical mechanism of action is unknown, although data are available to suggest that the drug modifies the peripheral metabolism of steroids as well as directly suppressing the adrenal cortex. Mitotane is used for treatment of inoperable adrenocortical tumours; Cushing's syndrome

Floxuridine is a pyrimidine analog that acts as an inhibitor of the S-phase of cell division. This selectively kills rapidly dividing cells. Floxuridine is an anti-metabolite. Anti-metabolites masquerade as pyramidine-like molecules which prevents normal pyrimidines from being incorporated into DNA during the S phase of the cell cycle. Flurouracil (the end-product of catabolism of floxuridine) blocks an enzyme which converts cytosine nucleosides into the deoxy derivative. In addition, DNA synthesis is further inhibited because fluoruracil blocks the incorporation of the thymdine nucleotide into the DNA strand. Floxuridine is used for palliative management of gastrointestinal adenocarcinoma metastatic to the liver, when given by continuous regional intra-arterial infusion in carefully selected patients who are considered incurable by surgery or other means. Also for the palliative management of liver cancer (usually administered by hepatic intra-arterial infusion).Floxuridine first gained FDA approval in December 1970 under the brand name FUDR. The drug was initially marketed by Roche, which also did a lot of the initial work on 5-fluorouracil. The National Cancer Institute was an early developer of the drug. Roche sold its FUDR product line in 2001 to F H Faulding, which became Mayne Pharma.

Cytarabine is a pyrimidine nucleoside analog. Cytarabine or cytosine arabinoside (Cytosar-U or Depocyt) is a chemotherapy agent used mainly in the treatment of cancers of white blood cells such as acute myeloid leukemia (AML) and non-Hodgkin lymphoma. It also has antiviral and immunosuppressant properties. Cytarabine is an antimetabolite antineoplastic agent that inhibits the synthesis of DNA. It is a cell cycle phase-specific, affecting cells only during the S phase of cell division. Intracellularly, cytarabine is converted into cytarabine-5-triphosphate (ara-CTP), which is the active metabolite. The mechanism of action is not completely understood, but it appears that ara-CTP acts primarily through inhibition of DNA polymerase. Incorporation into DNA and RNA may also contribute to cytarabine cytotoxicity. Cytarabine is cytotoxic to a wide variety of proliferating mammalian cells in culture.The drug has a short plasma half-life, low stability and limited bioavailability. Overdosing of patients with continuous infusions may lead to side effects. Thus, various prodrug strategies and delivery systems have been explored extensively to enhance the half-life, stability and delivery of cytarabine. Alternative, delivery systems of cytarabine have emerged for the treatment of different cancers. The liposomal-cytarabine formulation has been approved for the treatment of lymphomatous meningitis.