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.

Cocaine is an alkaloid ester extracted from the leaves of plants including coca. Cocaine is a local anesthetic and vasoconstrictor and is clinically used for that purpose, particularly in the eye, ear, nose, and throat. It also has powerful central nervous system effects similar to the amphetamines and is a drug of abuse. Cocaine, like amphetamines, acts by multiple mechanisms on brain catecholaminergic neurons; the mechanism of its reinforcing effects is thought to involve inhibition of dopamine uptake. Cocaine is addictive due to its effect on the reward pathway in the brain. After a short period of use, there is a high risk that dependence will occur. Its use also increases the risk of stroke, myocardial infarction, lung problems in those who smoke it, blood infections, and sudden cardiac death. Cocaine sold on the street is commonly mixed with local anesthetics, cornstarch, quinine, or sugar which can result in additional toxicity. Following repeated doses, a person may have decreased the ability to feel pleasure and be very physically tired. Cocaine acts by inhibiting the reuptake of serotonin, norepinephrine, and dopamine. This results in greater concentrations of these three neurotransmitters in the brain. It can easily cross the blood-brain barrier and may lead to the breakdown of the barrier.

Morphine is one of the most important and widely used opioid for the treatment of chronic and acute pain: the very wide interindividual variability in the patients’ response to the drug may have genetic derivations. Sulphate salt of morphine sold under the many brand names, one of them, DURAMORPH, which is indicated for the management of pain severe enough to require use of an opioid analgesic by intravenous administration, and for which alternative treatments are not expected to be adequate. In addition for the epidural or intrathecal management of pain without attendant loss of motor, sensory, or sympathetic function. Morphine is a full opioid agonist and is relatively selective for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of morphine is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with morphine. The precise mechanism of the analgesic action is unknown. However, specific CNS opioid receptors for endogenous compounds with opioid-like activity have been identified throughout the brain and spinal cord and are thought to play a role in the analgesic effects of this drug. Morphine has a high potential for addiction and abuse. Common side effects include drowsiness, vomiting, and constipation. Caution is advised when used during pregnancy or breast-feeding, as morphine will affect the baby.

Miconazole is a synthetic imidazole derivative, a topical antifungal agent for use in the local treatment of vaginal, and skin and nail infections due to yeasts and dermatophytes. It is particularly active against Candida spp., Trichophyton spp., Epidermophyton spp., Microsporum spp. and Pityrosporon orbiculare (Malassezia furfur), but also possesses some activity against Gram-positive bacteria. It binds to the heme moiety of the fungal cytochrome P-450 dependent enzyme lanosterol 14-alpha-demethlyase. Inhibits 14-alpha-demethlyase, blocks formation of ergosterol and leads to the buildup of toxic methylated 14-a-sterols. Miconazole also affects the synthesis of triglycerides and fatty acids and inhibits oxidative and peroxidative enzymes, increasing the amount of active oxygen species within the cell.

Brompheniramine is an antihistaminergic medication of the propylamine class. It is a first-generation antihistamine, which is used for the treatment of the symptoms of the common cold and allergic rhinitis, such as runny nose, itchy eyes, watery eyes, and sneezing. In allergic reactions, an allergen interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Brompheniramine is a histamine H1 antagonist of the alkylamine class. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies. Brompheniramine is metabolised by cytochrome P450s. The halogenated alkylamine antihistamines all exhibit optic isomerism and brompheniramine products contain racemic brompheniramine maleate whereas dexbrompheniramine (Drixoral) is the dextrorotary (right-handed) stereoisomer.

Dextromethorphan is a non-narcotic morphine derivative widely used as an antitussive for almost 40 years. It has attracted attention due to its anticonvulsant and neuroprotective properties. It is a cough suppressant in many over-the-counter cold and cough medicines. In 2010, the FDA approved the combination product dextromethorphan/quinidine for the treatment of pseudobulbar affect. Dextromethorphan suppresses the cough reflex by a direct action on the cough center in the medulla of the brain. Dextromethorphan shows high-affinity binding to several regions of the brain, including the medullary cough center. This compound is an NMDA receptor antagonist and acts as a non-competitive channel blocker. It is one of the widely used antitussives and is used to study the involvement of glutamate receptors in neurotoxicity. Dextromethorphan (DM) is a sigma-1 receptor agonist and an uncompetitive NMDA receptor antagonist. The mechanism by which dextromethorphan exerts therapeutic effects in patients with pseudobulbar affect is unknown. Dextromethorphan should not be taken with monoamine oxidase inhibitors due to the potential for serotonin syndrome. Dextromethorphan is extensively metabolized by CYP2D6 to dextrorphan, which is rapidly glucuronidated and unable to cross the blood-brain barrier.

Oxytetracycline, a tetracycline analog isolated from the actinomycete streptomyces rimosus, was the second of the broad-spectrum tetracycline group of antibiotics to be discovered The drug is used for the prophylaxis and local treatment of superficial ocular infections due to oxytetracycline- and polymyxin-sensitive organisms for animal use only. These infections include the following: Ocular infections due to streptococci, rickettsiae E. coli, and A. aerogenes (such as conjunctivitis, keratitis, pinkeye, corneal ulcer, and blepharitis in dogs); ocular infections due to secondary bacterial complications associated with distemper in dogs; and ocular infections due to bacterial inflammatory conditions which may occur secondary to other diseases in dogs. Allergic reactions may occasionally occur. Treatment should be discontinued if reactions are severe. If new infections due to nonsensitive bacteria or fungi appear during therapy, appropriate measures should be taken. Oxytetracycline inhibits cell growth by inhibiting translation. It binds to the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. The binding is reversible in nature. Oxytetracycline is lipophilic and can easily pass through the cell membrane or passively diffuses through porin channels in the bacterial membrane.

Chlorpheniramine is an antihistamine. Chlorpheniramine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. Chlorpheniramine is used for relieving symptoms of sinus congestion, sinus pressure, runny nose, watery eyes, itching of the nose and throat, and sneezing due to upper respiratory infections (eg, colds), allergies, and hay fever. In addition to being a histamine H1 receptor (HRH1) antagonist, chlorphenamine has been shown to work as a serotonin-norepinephrine reuptake inhibitor or SNRI.

Chlorcyclizine is a first generation phenylpiperazine class antihistamine used to treat urticaria, rhinitis, pruritus, and other allergy symptoms. Chlorcyclizine also has some local anesthetic, anticholinergic, and antiserotonergic properties, and can be used as an antiemetic. Chlorcyclizine temporarily relieves the symptoms due to hay fever or other upper respiratory allergies. It has also being shown to possess in vitro and in vivo activity against hepatitis C virus.

Dibucaine is used as a local anesthetic for surface anesthesia. It is one of the most potent and toxic of the long-acting local anesthetics and its parenteral use is restricted to spinal anesthesia. Dibucaine is used to temporarily relieve pain and itching due to: hemorrhoids or other anorectal disorders, sunburn, minor burns, minor cuts; scrapes, insect bites, minor skin irritation. This drug acts via blocking of nerve impulses by decreasing the neuronal membrane's permeability to sodium ions through sodium channel blocking. This reversibly stabilizes the membrane and inhibits depolarization, resulting in the failure of a propagated action potential and subsequent conduction blockade.