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.

Acetylcholine is the neurotransmitter at neuromuscular junctions, at synapses in the ganglia of the visceral motor system, and at a variety of sites within the central nervous system. Whereas a great deal is known about the function of cholinergic transmission at the neuromuscular junction and at ganglionic synapses, the actions of acetylcholine in the central nervous system are not as well understood. Cholinergic system is an important system and a branch of the autonomic nervous system which plays an important role in memory, digestion, control of heart beat, blood pressure, movement and many other functions. Acetylcholine in the brain alters neuronal excitability, influences synaptic transmission, induces synaptic plasticity, and coordinates firing of groups of neurons. Miochol®-E (acetylcholine chloride intraocular solution) is used to obtain miosis of the iris in seconds after delivery of the lens in cataract surgery, in penetrating keratoplasty, iridectomy and other anterior segment surgery where rapid miosis may be required.

Oxazepam is the first of a chemical series of compounds, the 3-hydroxybenzodiazepinones. A therapeutic agent providing versatility and flexibility in control of common emotional disturbances, this product exerts prompt action in a wide variety of disorders associated with anxiety, tension, agitation and irritability, and anxiety associated with depression. Oxazepam has distinguished itself clinically from other benzodiazepines by virtue of its excellent tolerance. Because of its excellent tolerance, dosage is very flexible, and it is, therefore, possible to utilize oxazepam in a wide spectrum of anxiety-related disorders including the psychoses. Oxazepam has been administered to humans by the oral route only. Usual ranges for kinetic parameters are: elimination half-life, 5 to 15 hours; volume of distribution, 0.6 to 2.0 L/kg; clearance, 0.9 to 2.0 ml/min/kg. Age and liver disease have a minimal influence on oxazepam kinetics, but renal disease is associated with a prolonged half-life and increased volume of distribution.

Prilocaine is a local anesthetic that is similar pharmacologically to lidocaine. Prilocaine binds to the intracellular surface of sodium channels which blocks the subsequent influx of sodium into the cell. Action potential propagation and never function is, therefore, prevented. This block is reversible and when the drug diffuses away from the cell, sodium channel function is restored and nerve propagation returns. Prilocaine acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Currently, Prilocaine is used most often for infiltration anesthesia in dentistry.

Doxapram is an analeptic agent (a stimulant of the central nervous system). The respiratory stimulant action is manifested by an increase in tidal volume associated with a slight increase in respiratory rate. A pressor response may result following doxapram administration. Provided there is no impairment of cardiac function, the pressor effect is more marked in hypovolemic than in normovolemic states. The pressor response is due to the improved cardiac output rather than peripheral vasoconstriction. Following doxapram administration, an increased release of catecholamines has been noted. Doxapram produces respiratory stimulation mediated through the peripheral carotid chemoreceptors. It is thought to stimulate the carotid body by inhibiting certain potassium channels. Used as temporary measure in hospitalized patients with acute respiratory insufficiency superimposed on chronic obstructive pulmonary disease.

Nortriptyline is a second-generation tricyclic antidepressant (TCA) marketed as the hydrochloride salt under the trade names Sensoval, Aventyl, Pamelor, Norpress, Allegron, Noritren and Nortrilen. Nortriptyline is used in the treatment of depression and childhood nocturnal enuresis. Its off-label uses include treatment of postherpetic neuralgia, angioedema and smoking Cessation, and attention deficit hyperactivity disorder in some neurological disorders. It is believed that nortriptyline either inhibits the reuptake of the neurotransmitter serotonin at the neuronal membrane or acts at beta-adrenergic receptors. Nortriptyline is US FDA-approved for the treatment of major depression. In the United Kingdom, it may also be used for treating nocturnal enuresis, with courses of treatment lasting no more than three months. The most common side effects include dry mouth, sedation, constipation, and increased appetite, mild blurred vision, tinnitus, occasionally hypomania or mania. An occasional side effect is a rapid or irregular heartbeat. Alcohol may exacerbate some of its side effects. However, fewer and milder side effects occur with nortriptyline than tertiary tricyclic antidepressants such as imipramine and amitriptyline. For this reason, nortriptyline is preferred to other tricyclic antidepressants, particularly with older adults, which also improves compliance.

Nalbuphine is a semi-synthetic opioid agonist-antagonist used commercially as an analgesic under a variety of trade names, including Nubain and Manfine. Nalbuphine is an agonist at kappa opioid receptors and an antagonist at mu opioid receptors. Nalbuphine analgesic potency is essentially equivalent to that of morphine on a milligram basis up to a dosage of approximately 30 mg. The opioid antagonist activity of Nalbuphine is one-fourth as potent as nalorphine and 10 times that of pentazocine. Nalbuphine is indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Nalbuphine can also be used as a supplement to balanced anesthesia, for preoperative and postoperative analgesia, and for obstetrical analgesia during labor and delivery. The onset of action of Nalbuphine occurs within 2 to 3 minutes after intravenous administration, and in less than 15 minutes following subcutaneous or intramuscular injection. The plasma half-life of nalbuphine is 5 hours, and in clinical studies, the duration of analgesic activity has been reported to range from 3 to 6 hours. Like pure µ-opioids, the mixed agonist-antagonist opioid class of drugs can cause side effects with initial administration of the drug but which lessen over time (“tolerance”). This is particularly true for the side effects of nausea, sedation and cognitive symptoms. These side effects can in many instances be ameliorated or avoided at the time of drug initiation by titrating the drug from a tolerable starting dose up to the desired therapeutic dose. An important difference between nalbuphine and the pure mu-opioid analgesic drugs is the “ceiling effect” on respiration. Respiratory depression is a potentially fatal side effect from the use of pure mu opioids. Nalbuphine has limited ability to depress respiratory function.

Desipramine is a tricyclic antidepressant that was approved by the FDA in 1964. It was derived from imipramine, which was the first tricyclic antidepressant to be manufactured. Desipramine is one of many tricyclic antidepressants, and this type of antidepressant gets its name due to its three-ring chemical structure. Desipramine, a secondary amine tricyclic antidepressant, is structurally related to both the skeletal muscle relaxant cyclobenzaprine and the thioxanthene antipsychotics such as thiothixene. It is the active metabolite of imipramine, a tertiary amine TCA. The acute effects of desipramine include inhibition of noradrenaline re-uptake at noradrenergic nerve endings and inhibition of serotonin (5-hydroxy tryptamine, 5HT) re-uptake at the serotoninergic nerve endings in the central nervous system. Desipramine exhibits greater noradrenergic re-uptake inhibition compared to the tertiary amine TCA imipramine. In addition to inhibiting neurotransmitter re-uptake, desipramine down-regulates beta-adrenergic receptors in the cerebral cortex and sensitizes serotonergic receptors with chronic use. The overall effect is increased serotonergic transmission. Antidepressant effects are typically observed 2 - 4 weeks following the onset of therapy though some patients may require up to 8 weeks of therapy prior to symptom improvement. Patients experiencing more severe depressive episodes may respond quicker than those with mild depressive symptoms. Desipramine is marketed under the trade name Norpramin, indicated for the treatment of depression.

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.

Diazepam is a benzodiazepine first discovered at Hoffman-La Roche in the late 1950s. Diazepam was approved by FDA for the treatment of anxiety disorders as well as for such conditions as skeletal muscle spasm, alcohol withdrawal syndrom and convulsions (under the most known brand Valium). The drug acts by binding to GABA-A receptors and potentiating GABA evoked current. Chronic diazepam use is associated with tolerance, dependence, and withdrawal.