Pitolisant (INN) or tiprolisant (USAN) is a histamine receptor inverse agonist/antagonist selective for the H3 subtype. It has stimulant and nootropic effects in animal studies and may have several medical applications, having been researched for the treatment of narcolepsy, for which it has been granted orphan drug status in the EU and US. It is currently in clinical trials for schizophrenia and Parkinson’s disease. Pitolisant hydrochloride was approved by European Medicine Agency (EMA) on Mar 31, 2016. It was developed and marketed as Wakix® by Bioprojet in EU. Wakix® is available as the tablet for oral use, containing 4.5 mg and 18 mg of Pitolisant hydrochloride. The initial dose of 9 mg (two 4.5 mg, tablets) per day, and it should be used at the lowest effective dose, depending on individual patient response and tolerance, according to an up-titration scheme, without exceeding the dose of 36 mg/day. Pitolisant was the first clinically used H3 receptor inverse agonist.

Lusutrombopag (trade name Mulpleta) is an orally bioavailable, small molecule thrombopoietin (TPO) receptor agonist being developed by Shionogi for chronic liver disease (CLD) patients with thrombocytopenia prior to elective invasive surgery. Lusutrombopag acts selectively on the human TPO receptor and activates signal transduction pathways that promote the proliferation and differentiation of bone marrow cells into megakaryocytes, thereby increasing platelet levels. In September 2015, Lusutrombopag received its first global approval in Japan for the improvement of CLD-associated thrombocytopenia in patients scheduled to undergo elective invasive procedures. Oral Lusutrombopag is rapidly absorbed, with a median time to maximum serum concentration (Tmax) of 3.8–4.0 h in healthy subjects administered single doses of oral Lusutrombopag 1, 2 or 4 mg, and 6 h in CLD patients with thrombocytopenia administered oral Lusutrombopag 3 mg once daily for 7 days. The major metabolic pathway for Lusutrombopag appears to be omega- and beta-oxidation. Lusutrombopag is a substrate of breast cancer resistance protein and P-glycoprotein, according to in vitro data.

Naldemedine (Symproic) is an opioid antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain. Naldemedine is an opioid antagonist with binding affinities for mu-, delta-, and kappa-opioid receptors. Naldemedine functions as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids. Naldemedine is a derivative of naltrexone to which a side chain has been added that increases the molecular weight and the polar surface area, thereby reducing its ability to cross the blood-brain barrier (BBB). Naldemedine is also a substrate of the P-glycoprotein (P-gp) efflux transporter. Based on these properties, the CNS penetration of naldemedine is expected to be negligible at the recommended dose levels, limiting the potential for interference with centrally-mediated opioid analgesia. Naldemedine was approved in 2017 in both the US and Japan for the treatment of Opioid-induced Constipation.

Levomilnacipran (1S, 2R/F2695) is an enantiomer of milnacipran, a serotonin/norepinephrine (5-HT/NE) reuptake inhibitor. Levomilnacipran is pharmacologically more active as compared with racemic mixture and dextromilnacipran (1R, 2S/F2696). The safety of the drug is also higher than the safety of a racemate, resulting in a beneficial impact on the therapeutic effect. Pierre Fabre and Forest Laboratories are developing levomilnacipran extended release (ER) [FETZIMA™], an enantiomer of milnacipran, for the treatment of major depressive disorder (MDD). In addition, Pierre Fabre (the originator of the compound) is developing the drug to improve recovery in patients with ischaemic stroke.

Carbamazepine is an analgesic, anti-epileptic agent that is FDA approved for the treatment of epilepsy, trigeminal neuralgia. It appears to act by reducing polysynaptic responses and blocking the post-tetanic potentiation. It depresses thalamic potential and bulbar and polysynaptic reflexes, including the linguomandibular reflex in cats. Commonly reported side effects of carbamazepine include: dizziness, drowsiness, nausea, ataxia, and vomiting. Carbamazepine is a potent inducer of hepatic CYP1A2, 2B6, 2C9/19, and 3A4 and may reduce plasma concentrations of concomitant medications mainly metabolized by CYP1A2, 2B6, 2C9/19, and 3A4 through induction of their metabolism, like Boceprevir, Cyclophosphamide, Aripiprazole, Tacrolimus, Temsirolimus and others.

Dexamethasone is an anti-inflammatory agent that is FDA approved for the treatment of many conditions, including rheumatic problems, a number of skin diseases, severe allergies, asthma, chronic obstructive lung disease, croup, brain swelling and others. Dexamethasone is a glucocorticoid agonist. Unbound dexamethasone crosses cell membranes and binds with high affinity to specific cytoplasmic glucocorticoid receptors. Adverse reactions are: Glaucoma with optic nerve damage, visual acuity and field defects; cataract formation; secondary ocular infection following suppression of host response; and perforation of the globe may occur; muscle weakness; osteoporosis and others. Aminoglutethimide may diminish adrenal suppression by corticosteroids. Macrolide antibiotics have been reported to cause a significant decrease in corticosteroid clearance.

Quercetin is a unique bioflavonoid that has been extensively studied by researchers over the past 30 years. Quercetin, the most abundant of the flavonoids (the name comes from the Latin –quercetum, meaning oak forest, quercus oak) consists of 3 rings and 5 hydroxyl groups. Quercetin is a member of the class of flavonoids called flavonoles and forms the backbone for many other flavonoids including the citrus flavonoids like rutin, hesperidins, Naringenin and tangeritin. It is widely distributed in the plant kingdom in rinds and barks. The best described property of Quercetin is its ability to act as antioxidant. Quercetin seems to be the most powerful flavonoids for protecting the body against reactive oxygen species, produced during the normal oxygen metabolism or are induced by exogenous damage [9, 10]. One of the most important mechanisms and the sequence of events by which free radicals interfere with the cellular functions seem to be the lipid peroxidation leading eventually the cell death. To protect this cellular death to happen from reactive oxygen species, living organisms have developed antioxidant line of defense systems [11]. These include enzymatic and non-enzymatic antioxidants that keep in check ROS/RNS level and repair oxidative cellular damage. The major enzymes, constituting the first line of defence, directly involved in the neutralization of ROS/RNS are: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) The second line of defence is represented by radical scavenging antioxidants such as vitamin C, vitamin A and plant phytochemicals including quercetin that inhibit the oxidation chain initiation and prevent chain propagation. This may also include the termination of a chain by the reaction of two radicals. The repair and de novo enzymes act as the third line of defence by repairing damage and reconstituting membranes. These include lipases, proteases, DNA repair enzymes and transferases. Quercetin is a specific quinone reductase 2 (QR2) inhibitor, an enzyme (along with the human QR1 homolog) which catalyzes metabolism of toxic quinolines. Inhibition of QR2 in plasmodium may potentially cause lethal oxidative stress. The inhibition of antioxidant activity in plasmodium may contribute to killing the malaria causing parasites.

Indirubin is derived from the Indigo Plant (Isatis Root, Isatis Leaf). It is used as part of a traditional Chinese herbal prescription called Dang Gui Long Hui Wan, to treat chronic myelogenous leukemia (CML). Indirubin inhibits DNA synthesis in several cell lines, in a cell-free assay and in vivo in rats with Walker-256 sarcoma. A weak binding of indirubin to DNA in vitro has been described. Indirubin inhibited all cyclin-dependent kinases (1,2,4,5) almost equally. Indirubin has been approved for clinical trials against chronic myelocytic and chronic granulocytic leukaemia. A few studies show that Indirubin is effective against psoriasis. Mild to severe nausea, vomiting, abdominal pain, diarrhea, headache, and edema are reported adverse events of Indirubin. Long-term oral ingestion has also occasionally been associated with hepatitis, pulmonary arterial hypertension and cardiac insufficiency.

Pitolisant (INN) or tiprolisant (USAN) is a histamine receptor inverse agonist/antagonist selective for the H3 subtype. It has stimulant and nootropic effects in animal studies and may have several medical applications, having been researched for the treatment of narcolepsy, for which it has been granted orphan drug status in the EU and US. It is currently in clinical trials for schizophrenia and Parkinson’s disease. Pitolisant hydrochloride was approved by European Medicine Agency (EMA) on Mar 31, 2016. It was developed and marketed as Wakix® by Bioprojet in EU. Wakix® is available as the tablet for oral use, containing 4.5 mg and 18 mg of Pitolisant hydrochloride. The initial dose of 9 mg (two 4.5 mg, tablets) per day, and it should be used at the lowest effective dose, depending on individual patient response and tolerance, according to an up-titration scheme, without exceeding the dose of 36 mg/day. Pitolisant was the first clinically used H3 receptor inverse agonist.

Naldemedine (Symproic) is an opioid antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain. Naldemedine is an opioid antagonist with binding affinities for mu-, delta-, and kappa-opioid receptors. Naldemedine functions as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids. Naldemedine is a derivative of naltrexone to which a side chain has been added that increases the molecular weight and the polar surface area, thereby reducing its ability to cross the blood-brain barrier (BBB). Naldemedine is also a substrate of the P-glycoprotein (P-gp) efflux transporter. Based on these properties, the CNS penetration of naldemedine is expected to be negligible at the recommended dose levels, limiting the potential for interference with centrally-mediated opioid analgesia. Naldemedine was approved in 2017 in both the US and Japan for the treatment of Opioid-induced Constipation.