Lamotrigine (marketed as Lamictal) is an anticonvulsant drug used in the treatment of epilepsy and bipolar disorder. The precise mechanism(s) by which lamotrigine exerts its anticonvulsant action are unknown. In animal models designed to detect anticonvulsant activity, lamotrigine was effective in preventing seizure spread in the maximum electroshock (MES) and pentylenetetrazol (scMet) tests, and prevented seizures in the visually and electrically evoked after-discharge (EEAD) tests for antiepileptic activity. Lamotrigine also displayed inhibitory properties in the kindling model in rats both during kindling development and in the fully kindled state. The relevance of these models to human epilepsy, however, is not known. One proposed mechanism of action of lamotrigine, the relevance of which remains to be established in humans, involves an effect on sodium channels. In vitro pharmacological studies suggest that lamotrigine inhibits voltage-sensitive sodium channels, thereby stabilizing neuronal membranes and consequently modulating presynaptic transmitter release of excitatory amino acids (e.g., glutamate and aspartate). Effect of Lamotrigine on N-Methyl d-Aspartate-Receptor Mediated Activity Lamotrigine did not inhibit N-methyl d-aspartate (NMDA)-induced depolarizations in rat cortical slices or NMDA-induced cyclic GMP formation in immature rat cerebellum, nor did lamotrigine displace compounds that are either competitive or noncompetitive ligands at this glutamate receptor complex (CNQX, CGS, TCHP). The IC50 for lamotrigine effects on NMDA-induced currents (in the presence of 3 uM of glycine) in cultured hippocampal neurons exceeded 100 uM. The mechanisms by which lamotrigine exerts its therapeutic action in bipolar disorder have not been established. The mechanisms that underpin the passage of lamotrigine at the blood-brain barrier to its site of action in the brain is poorly understood.

Vinorelbine (trade name Navelbine) is a semi-synthetic vinca-alkaloid with a broad spectrum of anti-tumour activity. Vinorelbine is a mitotic spindle poison that impairs chromosomal segregation during mitosis. It blocks cells at G2/M. Microtubules (derived from polymers of tubulin) are the principal target of vinorelbine. Vinorelbine was developed by Pierre Fabre under licence from the CNRS in France. NAVELBINE (vinorelbine tartrate) as a single agent or in combination is indicated for the first line treatment of non small cell lung cancer and advanced breast cancer.

Cysteamine (trade name CYSTAGON) is a cystine-depleting agent indicated for the treatment of corneal cystine crystal accumulation in patients with cystinosis. Cystinosis is an autosomal recessive inborn error of metabolism in which the transport of cystine out of lysosomes is abnormal; in the nephropathic form, accumulation of cystine and formation of crystals damage various organs, especially the kidney, leading to renal tubular Fanconi Syndrome and progressive glomerular failure, with end-stage renal failure by the end of the first decade of life. In four studies of cystinosis patients before cysteamine was available, renal death (need for transplant or dialysis) occurred at the median age of fewer than 10 years. Patients with cystinosis also experience growth failure, rickets, and photophobia due to cystine deposits in the cornea. With time most organs are damaged, including the retina, muscles and central nervous system. Cysteamine is an aminothiol that participates within lysosomes in a thiol-disulfide interchange reaction converting cystine into cysteine and cysteine-cysteamine mixed disulfide, both of which can exit the lysosome in patients with cystinosis.

Tacrolimus, previously known as FK506, is the active ingredient in Prograf. Tacrolimus is a macrolide immunosuppressant produced by Streptomyces tsukubaensis. It reduces peptidyl-prolyl isomerase activity by binding to the immunophilin FKBP-12 (FK506 binding protein) creating a new complex. This FKBP12-FK506 complex interacts with and inhibits calcineurin thus inhibiting both T-lymphocyte signal transduction and IL-2 transcription. Tacrolimus inhibits T-lymphocyte activation, although the exact mechanism of action is not known. Experimental evidence suggests that tacrolimus binds to an intracellular protein, FKBP-12. A complex of tacrolimus-FKBP-12, calcium, calmodulin, and calcineurin is then formed and the phosphatase activity of calcineurin inhibited. This effect may prevent the dephosphorylation and translocation of nuclear factor of activated T-cells (NF-AT), a nuclear component thought to initiate gene transcription for the formation of lymphokines (such as interleukin-2, gamma interferon). The net result is the inhibition of T-lymphocyte activation (i.e., immunosuppression). Prograf is indicated for the prophylaxis of organ rejection in patients receiving allogeneic liver transplants, kidney transplants, heart transplants. It has also been used in a topical preparation in the treatment of severe atopic dermatitis.

Fenofibrate is a drug of the fibrate class. It is mainly used to reduce cholesterol levels in people at risk of cardiovascular disease. It’s used as adjunctive therapy to diet to reduce elevated LDL-C, Total-C,Triglycerides and Apo B, and to increase HDL-C in adult patients with primary hypercholesterolemia or mixed dyslipidemia (Fredrickson Types IIa and IIb). Fenofibrate is a fibric acid derivative, a prodrug comprising fenofibric acid linked to an isopropyl ester. Fenofibrate is rapidly hydrolyzed after oral ingestion to its pharmacologically active form, fenofibric acid. The effects of fenofibric acid seen in clinical practice have been explained in vivo in transgenic mice and in vitro in human hepatocyte cultures by the activation of peroxisome proliferator activated receptor α (PPARα). It lowers lipid levels by activating peroxisome proliferator-activated receptor alpha (PPARα). PPARα activates lipoprotein lipase and reduces apoprotein CIII (an inhibitor of lipoprotein lipase activity), which increases lipolysis and elimination of triglyceride-rich particles from plasma. The resulting fall in triglycerides produces an alteration in the size and composition of LDL from small, dense particles (which are thought to be atherogenic due to their susceptibility to oxidation), to large buoyant particles. These larger particles have a greater affinity for cholesterol receptors and are catabolized rapidly. PPARα also increases apoproteins AI and AII, reduces VLDL- and LDL-containing apoprotein B, and increases HDL-containing apoprotein AI and AII.Fenofibrate also reduces serum uric acid levels in hyperuricemic and normal individuals by increasing the urinary excretion of uric acid. Fenofibrate also has an off-label use as uricosuric therapy in people who have gout.

Felbamate is an antiepileptic indicated as monotherapy or as an adjunct to other anticonvulsants for the treatment of partial seizures resulting from epilepsy. Receptor-binding studies in vitro indicate that felbamate has weak inhibitory effects on GABA-receptor binding, benzodiazepine receptor binding, and is devoid of activity at the MK-801 receptor binding site of the NMDA receptor-ionophore complex. However, felbamate does interact as an antagonist at the strychnine-insensitive glycine recognition site of the NMDA receptor-ionophore complex. The mechanism by which felbamate exerts its anticonvulsant activity is unknown, but in animal test systems designed to detect anticonvulsant activity, felbamate has properties in common with other marketed anticonvulsants. In vitro receptor binding studies suggest that felbamate may be an antagonist at the strychnine-insensitive glycine-recognition site of the N-methyl-D-aspartate (NMDA) receptor-ionophore complex. Antagonism of the NMDA receptor glycine binding site may block the effects of the excitatory amino acids and suppress seizure activity. Animal studies indicate that felbamate may increase the seizure threshold and may decrease seizure spread. It is also indicated that felbamate has weak inhibitory effects on GABA-receptor binding, benzodiazepine receptor binding. Felbamate should be used only in those patients who respond inadequately to alternative treatments and whose epilepsy is so severe that a substantial risk of aplastic anemia and/or liver failure is deemed acceptable in light of the benefits conferred by its use. Felbatol is the brand name used in the United States for felbamate.

Sotalol has both beta-adrenoreceptor blocking and cardiac action potential duration prolongation antiarrhythmic properties. Sotalol inhibits response to adrenergic stimuli by competitively blocking β1-adrenergic receptors within the myocardium and β2-adrenergic receptors within bronchial and vascular smooth muscle. It is FDA approved for the treatment of ventricular arrhythmias, symptomatic atrial fibtillation, symptomatic atriall flutter. Common adverse reactions include bradyarrhythmia, chest pain, lightheadedness, palpitations, rash, nausea, dizziness, headache, dyspnea, fatigue. Proarrhythmic events were more common in sotalol treated patients also receiving digoxin. Sotalol should be administered with caution in conjunction with calcium blocking drugs because of possible additive effects on atrioventricular conduction or ventricular function. Patients treated with sotalol plus a catecholamine depletor should therefore be closely monitored for evidence of hypotension and/or marked bradycardia which may produce syncope.

Etodolac is an anti-inflammatory agent with analgesic and antipyretic properties. It is used to treat osteoarthritis, rheumatoid arthritis and control acute pain. The therapeutic effects of etodolac are achieved via inhibition of the synthesis of prostaglandins involved in fever, pain, swelling and inflammation. Etodolac is administered as a racemate. As with other NSAIDs, the S-form has been shown to be active while the R-form is inactive. Both enantiomers are stable and there is no evidence of R- to S- conversion in vivo. Similar to other NSAIDs, the anti-inflammatory effects of etodolac result from inhibition of the enzyme cycooxygenase (COX). This decreases the synthesis of peripheral prostaglandins involved in mediating inflammation. Etodolac binds to the upper portion of the COX enzyme active site and prevents its substrate, arachidonic acid, from entering the active site. Etodolac was previously thought to be a non-selective COX inhibitor, but it is now known to be 5 – 50 times more selective for COX-2 than COX-1. Antipyresis may occur by central action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat loss. Etodolac is used for acute and long-term management of signs and symptoms of osteoarthritis and rheumatoid arthritis, as well as for the management of pain. Lodine, the brand-name formulation of the drug, has been discontinued in the United States, and only the generic form of etodolac is available.

Fludarabine or fludarabine phosphate is a chemotherapy drug used in the treatment of hematological malignancies (cancers of blood cells such as leukemias and lymphomas). It is a purine analog, which interferes with DNA synthesis. Fludarabine phosphate is a fluorinated nucleotide analog of the antiviral agent vidarabine, 9-β-D-arabinofuranosyladenine (ara-A), that is relatively resistant to deamination by adenosine deaminase. Fludarabine (marketed as fludarabine phosphate under the trade name Fludara) is a chemotherapy drug used in the treatment of hematological malignancies. Fludarabine phosphate is rapidly dephosphorylated to 2-fluoro-ara-A and then phosphorylated intracellularly by deoxycytidine kinase to the active triphosphate, 2-fluoro-ara-ATP. This metabolite appears to act by inhibiting DNA polymerase alpha, ribonucleotide reductase and DNA primase, thus inhibiting DNA synthesis. The mechanism of action of this antimetabolite is not completely characterized and may be multi-faceted.

Estazolam, a triazolobenzodiazepine derivative, is an oral hypnotic agent with anticonvulsant, hypnotic, and muscle relaxant properties. It has been shown in some cases to be more potent than diazepam or nitrazepam. Benzodiazepines bind nonspecifically to benzodiazepine receptors, 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 GABA by increasing GABA affinity for the GABA receptor. Binding of the inhibitory neurotransmitter GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell. Used for the short-term management of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings. Marketed under the brand names ProSom, Eurodin.