Flecainide is a potent anti-arrhythmia agent, effective in a wide range of ventricular and atrial arrhythmias and tachycardias. Flecainide has local anesthetic activity and belongs to the membrane stabilizing (Class 1) group of antiarrhythmic agents; it has electrophysiologic effects characteristic of the IC class of antiarrhythmics. Flecainide 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. Flecainide is a sodium channel blocker, binding to voltage gated sodium channels. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. Flecainide is sold under the trade name Tambocor (manufactured by 3M pharmaceuticals). Flecainide went off-patent on February 10, 2004. In addition to being marketed as Tambocor, it is also available in generic version and under the trade names Almarytm, Apocard, Ecrinal, and Flécaine.

Amiodarone is an antiarrhythmic with mainly class III properties, but it possesses electrophysiologic characteristics of all four Vaughan Williams classes. Like class I drugs, amiodarone blocks sodium channels at rapid pacing frequencies, and like class II drugs, amiodarone exerts a noncompetitive antisympathetic action. In addition to blocking sodium channels, amiodarone blocks myocardial potassium channels, which contributes to slowing of conduction and prolongation of refractoriness. It is indicated for initiation of treatment and prophylaxis of frequently recurring ventricular fibrillation and hemodynamically unstable ventricular tachycardia in patients refractory to other therapy. The most common adverse reactions (1-2%) leading to discontinuation of intravenous amiodarone therapy are hypotension, asystole/cardiac arrest/pulseless electrical activity, VT, and cardiogenic shock. Other important adverse reactions are, torsade de pointes (TdP), congestive heart failure, and liver function test abnormalities. Fluoroquinolones, macrolide antibiotics, and azoles are known to cause QTc prolongation. There have been reports of QTc prolongation, with or without TdP, in patients taking amiodarone when fluoroquinolones, macrolide antibiotics, or azoles were administered concomitantly. Since amiodarone is a substrate for CYP3A and CYP2C8, drugs/substances that inhibit these isoenzymes may decrease the metabolism and increase serum concentration of amiodarone.

Pimozide (Orap) is a diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to haloperidol for the suppression of vocal and motor tics in patients with Tourette syndrome. It is not intended as a treatment of first choice nor is it intended for the treatment of tics that are merely annoying or cosmetically troublesome. It should be reserved for use in Tourette’s Disorder patients whose development and/or daily life function is severely compromised by the presence of motor and phonic tics. Evidence supporting approval of pimozide for use in Tourette’s Disorder was obtained in two controlled clinical investigations, which enrolled patients between the ages of 8 and 53 years. Most subjects in the two trials were 12 or older. Pimozide is an orally active antipsychotic drug product, which shares with other antipsychotics the ability to blockade dopaminergic receptors on neurons in the central nervous system. Although its exact mode of action has not been established, the ability of pimozide to suppress motor and phonic tics in Tourette’s Disorder is thought to be a function of its dopaminergic blocking activity. However, receptor blockade is often accompanied by a series of secondary alterations in central dopamine metabolism and function which may contribute to both pimozide’s therapeutic and untoward effects. In addition, pimozide, in common with other antipsychotic drugs, has various effects on other central nervous system receptor systems which are not fully characterized.

Clemastine is an antihistamine with anticholinergic (drying) and sedative side effects. Clemastine is a selective histamine H1 antagonist and 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. It is used for the relief of symptoms associated with allergic rhinitis such as sneezing, rhinorrhea, pruritus and acrimation. Also for the management of mild, uncomplicated allergic skin manifestations of urticaria and angioedema. Used as self-medication for temporary relief of symptoms associated with the common cold.

Droperidol produces marked tranquilization and sedation. It allays apprehension and provides a state of mental detachment and indifference while maintaining a state of reflex alertness. Droperidol produces an antiemetic effect as evidenced by the antagonism of apomorphine in dogs. It lowers the incidence of nausea and vomiting during surgical procedures and provides antiemetic protection in the postoperative period. Droperidol potentiates other CNS depressants. It produces mild alpha-adrenergic blockade, peripheral vascular dilatation and reduction of the pressor effect of epinephrine. It can produce hypotension and decreased peripheral vascular resistance and may decrease pulmonary arterial pressure (particularly if it is abnormally high). It may reduce the incidence of epinephrine-induced arrhythmias, but it does not prevent other cardiac arrhythmias. The exact mechanism of action is unknown, however, droperidol causes a CNS depression at subcortical levels of the brain, midbrain, and brainstem reticular formation. It may antagonize the actions of glutamic acid within the extrapyramidal system. It may also inhibit cathecolamine receptors and the reuptake of neurotransmiters and has strong central antidopaminergic action and weak central anticholinergic action. It can also produce ganglionic blockade and reduced affective response. The main actions seem to stem from its potent Dopamine (2) receptor antagonism with minor antagonistic effects on alpha-1 adrenergic receptors as well. Droperidol is used to produce tranquilization and to reduce the incidence of nausea and vomiting in surgical and diagnostic procedures.

Mepivicaine is a local anesthetic of the amide type. Mepivicaine as a reasonably rapid onset and medium duration and is known by the proprietary names as Carbocaine and Polocaine. Mepivicaine is used in local infiltration and regional anesthesia. Systemic absorption of local anesthetics produces effects on the cardiovascular and central nervous systems. At blood concentrations achieved with normal therapeutic doses, changes in cardiac conduction, excitability, refractoriness, contractility, and peripheral vascular resistance are minimal. Mepivicaine is used for production of local or regional analgesia and anesthesia by local infiltration, peripheral nerve block techniques, and central neural techniques including epidural and caudal blocks.

Prochlorperazine is a piperazine phenothiazine antipsychotic which block postsynaptic mesolimbic dopaminergic receptors in the brain and has antiemetic effects by its antagonist actions in the D2 dopamine receptors in the chemoreceptor trigger zone. It also exhibits alpha-adrenergic blocking effect on α1 receptros and may depress the release of hypothalamic and hypophyseal hormones. Prochlorperazine is used for the control of severe nausea and vomiting, for the treatment of schizophrenia. Prochlorperazine is effective for the short-term treatment of generalized non-psychotic anxiety. Prochlorperazine may be an effective treatment of acute headaches and refractory chronic daily headache.

Diphenhydramine is an antihistamine which is used in the combination with naproxen sodium for the relief of occasional sleeplessness when associated with minor aches and pains. Diphenhydramine has a role nighttime sleep-aid and naproxen sodium is a pain reliever. In addition, diphenhydramine used in relieving symptoms in patients with moderate-to-severe seasonal allergic rhinitis. Diphenhydramine acts as an antagonist of histamine H1 receptor. Besides, was shown potential to repurpose diphenhydramine as an anti-melanoma therapeutic agent, it induces melanoma cell apoptosis by suppressing STAT3/MCL-1 survival signaling pathway.

Arena Pharmaceuticals was developing APD-597 (JNJ-38431055), a small molecule, an orally active agonist of the G-protein coupled receptor 119 (GPR119), for the treatment of Type 2 diabetes mellitus. JNJ-38431055 was selected for preclinical development based on a good balance between agonist potency, intrinsic activity and in particular on its good solubility and reduced drug-drug interaction potential. In addition, extensive in vivo studies showed a more favorable metabolic profile that may avoid the generation of long-lasting metabolites with the potential to accumulate in clinical studies. In humans, single-dose oral JNJ-38431055 increased postmeal plasma glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and peptide YY (PYY) concentrations but did not significantly decrease glucose excursion or increase insulin secretion. However, in a graded glucose infusion study, JNJ-38431055 was shown to induce a higher insulin secretion rate (ISR) relative to placebo at elevated plasma glucose levels. These studies provide evidence for the potential efficacy of JNJ-38431055 as an antidiabetes agent in humans.

MK-0773 is an orally active selective androgen receptor modulator. The safety and efficacy of MK-0773 was evaluated in sarcopenic elderly women. The MK-0773- induced improvements in lean body mass were not accompanied by statistically significant improvements in physical function. Higher dose of MK-0773 or longer duration of therapy might have resulted in improvements in physical function, but liver transaminase elevations likely preclude further development of MK-0773. Drug-candidate had been in phase I clinical trials for the treatment of osteoporosis.