Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Zidovudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. Zidovudine, a structural analog of thymidine, is a prodrug that must be phosphorylated to its active 5′-triphosphate metabolite, zidovudine triphosphate (ZDV-TP). It inhibits the activity of HIV-1 reverse transcriptase (RT) via DNA chain termination after incorporation of the nucleotide analogue. It competes with the natural substrate dGTP and incorporates itself into viral DNA. It is also a weak inhibitor of cellular DNA polymerase α and γ. Zidovudine is used in combination with other antiretroviral agents for the treatment of human immunovirus (HIV) infections. Zidovudine is marketed as Retrovir.

Sulbactam is a β-lactamase inhibitor given in combination with β-lactam antibiotics to inhibit β-lactamase, an enzyme produced by bacteria that destroys the antibiotics. Sulbactam in combination with semisynthetic antibiotic ampicillin sodium is indicated for the treatment of infections due to susceptible strains of the designated microorganisms: Skin and Skin Structure Infections caused by beta-lactamase producing strains of Staphylococcus aureus, Escherichia coli etc; Intra-Abdominal Infections caused by beta-lactamase producing strains of Escherichia coli, Klebsiella spp. (including K. Pneumoniae) tec; Gynecological Infections caused by beta-lactamase producing strains of Escherichia coli, and Bacteroides spp. (including B. fragilis).

Midazolam, previously marketed under the trade name Versed, is a medication used for anesthesia, procedural sedation, trouble sleeping, and severe agitation. Midazolam is a short-acting benzodiazepine central nervous system (CNS) depressant. Pharmacodynamic properties of midazolam and its metabolites, which are similar to those of other benzodiazepines, include sedative, anxiolytic, amnesic and hypnotic activities. Benzodiazepine pharmacologic effects appear to result from reversible interactions with the γ-amino butyric acid (GABA) benzodiazepine receptor in the CNS, the major inhibitory neurotransmitter in the central nervous system. The action of midazolam is readily reversed by the benzodiazepine receptor antagonist, flumazenil. Data from published reports of studies in pediatric patients clearly demonstrate that oral midazolam provides safe and effective sedation and anxiolysis prior to surgical procedures that require anesthesia as well as before other procedures that require sedation but may not require anesthesia. The most commonly reported effective doses range from 0.25 to 1 mg/kg in children (6 months to <16 years). The single most commonly reported effective dose is 0.5 mg/kg. Time to onset of effect is most frequently reported as 10 to 20 minutes. The effects of midazolam on the CNS are dependent on the dose administered, the route of administration, and the presence or absence of other medications.

Hydroquinone, aka benzene-1,4-diol or quinol, is an aromatic organic compound that is a type of phenol, a derivative of benzene, having the chemical formula C6H4(OH)2. Its chemical structure features two hydroxyl groups bonded to a benzene ring in a para position. It is a white granular solid. Substituted derivatives of this parent compound are also referred to as hydroquinones. The name "hydroquinone" was coined by Friedrich Wöhler in 1843. In human medicine, hydroquinone is used as a topical application in skin whitening to reduce the color of skin. It does not have the same predisposition to cause dermatitis as metol does. In 2006, the United States Food and Drug Administration revoked its previous approval of hydroquinone and proposed a ban on all over-the-counter preparations. The FDA stated that hydroquinone cannot be ruled out as a potential carcinogen. This conclusion was reached based on the extent of absorption in humans and the incidence of neoplasms in rats in several studies where adult rats were found to have increased rates of tumours, including thyroid follicular cell hyperplasias, anisokaryosis (variation in nuclei sizes), mononuclear cell leukemia, hepatocellular adenomas and renal tubule cell adenomas. One of the components in TRI-LUMA Cream, hydroquinone, is a depigmenting agent, and may interrupt one or more steps in the tyrosine-tyrosinase pathway of melanin synthesis. However, the mechanism of action of the active ingredients in TRI-LUMA Cream in the treatment of melasma is unknown.

Cyclosporins are cyclic polypeptide macrolides that were originally derived from the soil fungus Tolypocladium inflatum. Cyclosporine (also known as cyclosporine A) was discovered by Sandoz and developed for the tretment of immune disorders. The drug was approved by FDA for such diseases as Rheumatoid Arthritis, Psoriasis (Neoral), Keratoconjunctivitis sicca (Restasis) and prevention of transplant rejections (Neoral and Sandimmune). Cyclosporine’s primary immunosuppressive mechanism of action is inhibition of T-lymphocyte function. Upon administration cyclosporine binds to cyclophilin A and thus inhibits calcineurin, leading to immune system suppression.

Triazolam is a short-acting benzodiazepine used as a hypnotic agent in the treatment of insomnia. Some countries temporarily withdrew triazolam from the market because of concerns about adverse reactions, mostly psychological, associated with higher dose ranges. Its use at lower doses with appropriate care and labeling has been reaffirmed by the FDA and most other countries. Triazolam has a shorter half-life than chlordiazepoxide, flurazepam, and prazepam and does not generate active metabolites. Benzodiazepines bind nonspecifically to bezodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABAA) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell. Triazolam is used for the short-term treatment of insomnia. Triazolam`s original brand name is Halcion. Triazolam is withdrawn in the United Kingdom due to risk of psychiatric adverse drug reactions. This drug continues to be available in the U.S. Internationally, triazolam is a Schedule IV drug under the Convention on Psychotropic Substances.

Praziquantel, marketed as Biltricide, is an anthelmintic used in humans and animals for the treatment of tapeworms and flukes. Specifically, it is effective against schistosoma, Clonorchis sinensis the fish tape worm Diphyllobothrium latum. Praziquantel works by causing severe spasms and paralysis of the worms' muscles. This paralysis is accompanied - and probably caused - by a rapid Ca 2+ influx inside the schistosome. Morphological alterations are another early effect of praziquantel. These morphological alterations are accompanied by an increased exposure of schistosome antigens at the parasite surface. The worms are then either completely destroyed in the intestine or passed in the stool. An interesting quirk of praziquantel is that it is relatively ineffective against juvenile schistosomes. While initially effective, effectiveness against schistosomes decreases until it reaches a minimum at 3-4 weeks. Effectiveness then increases again until it is once again fully effective at 6-7 weeks. Glutathione S-transferase (GST), an essential detoxification enzyme in parasitic helminths, is a major vaccine target and a drug target against schistosomiasis. Schistosome calcium ion channels are currently the only known target of praziquantel. The antibiotic rifampicin decreases plasma concentrations of praziquantel. Carbamazepine and phenytoin are reported to reduce the bioavailability of praziquantel. Chloroquine reduces the bioavailability of praziquantel. The drug cimetidine heightens praziquantel bioavailability.

Vecuronium is a neuromuscular blocking agent. Vecuronium operates by competing for the cholinoceptors at the motor end plate thereby exerting its muscle-relaxing properties which are used adjunctively to general anesthesia. Vecuronium is a bisquaternary nitrogen compound that acts by competitively binding to nicotinic cholinergic receptors. The binding of vecuronium decreases the opportunity for acetylcholine to bind to the nicotinic receptor at the postjunctional membrane of the myoneural junction. As a result, depolarization is prevented, calcium ions are not released and muscle contraction does not occur. Vecuronium is indicated as an adjunct to general anesthesia, to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation.

Trazodone (brand name Oleptro, Desyrel, etc) is a serotonin uptake inhibitor that is used as an antidepressive agent. Trazodone binds to the 5-HT2 receptor, it acts as a serotonin agonist at high doses and a serotonin antagonist at low doses. Like fluoxetine, trazodone's antidepressant activity likely results from blockage of serotonin reuptake by inhibiting serotonin reuptake pump at the presynaptic neuronal membrane. If used for long time periods, postsynaptic neuronal receptor binding sites may also be affected. The sedative effect of trazodone is likely the result of alpha-adrenergic blocking action and modest histamine blockade at the H1 receptor. It weakly blocks presynaptic alpha2-adrenergic receptors and strongly inhibits postsynaptic alpha1 receptors. Trazodone does not affect the reuptake of norepinephrine or dopamine within the CNS. Because of its lack of anticholinergic side effects, trazodone is especially useful in situations in which antimuscarinic effects are particularly problematic (e.g., in patients with benign prostatic hyperplasia, closed-angle glaucoma, or severe constipation). Trazodone's propensity to cause sedation is a dual-edged sword. For many patients, the relief from agitation, anxiety, and insomnia can be rapid; for other patients, including those individuals with considerable psychomotor retardation and feelings of low energy, therapeutic doses of trazodone may not be tolerable because of sedation. Trazodone elicits orthostatic hypotension in some patients, probably as a consequence of α1-adrenergic receptor blockade. Mania has been observed in association with trazodone treatment, including in patients with bipolar disorder, as well as in patients with previous diagnoses of major depression. Compared to the reversible MAOI antidepressant drug moclobemide, significantly more impairment of vigilance occurs with trazodone.

Daunorubicin, also known as daunomycin, is a chemotherapy medication used to treat cancer. Specifically, it is used for acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), and Kaposi's sarcoma. Similar to doxorubicin, daunorubicin interacts with DNA by intercalation and inhibition of macromolecular biosynthesis. This inhibits the progression of the enzyme topoisomerase II, which relaxes supercoils in DNA for transcription. Daunorubicin stabilizes the topoisomerase II complex after it has broken the DNA chain for replication, preventing the DNA double helix from being resealed and thereby stopping the process of replication. On binding to DNA, daunomycin intercalates, with its daunosamine residue directed toward the minor groove. It has the highest preference for two adjacent G/C base pairs flanked on the 5' side by an A/T base pair. Daunorubicin should only be administered in a rapid intravenous infusion. It should not be administered intramuscularly or subcutaneously, since it may cause extensive tissue necrosis. It should also never be administered intrathecally (into the spinal canal), as this will cause extensive damage to the nervous system and may lead to death.