Halofantrine is a blood schizonticidal antimalarial agent with no apparent action on the sporozoite, gametocyte or hepatic stages of the infection. It is used only to treat but not to prevent malaria. Has been marketed by GlaxoSmithKline as HALFAN (halofantrine hydrochloride) in 250 mg tablets indicated for the treatment of adults who can tolerate oral medication and who have mild to moderate malaria (equal to or less than 100,000 parasites/mm3) caused by Plasmodium falciparum or Plasmodium vivax. Among side effects is cardiac arrhythmia. It belongs to the phenanthrene class of compounds that includes quinine and lumefantrine. It was reported that halofantrine binds to hematin in vitro (crystal structure of the complex) and to to plasmpesin, a haemoglobin degrading enzyme unique to the malarial parasites.

Bepridil is a calcium channel blocker that has well characterized anti-anginal properties and known but poorly characterized type 1 anti-arrhythmic and anti-hypertensive properties. It has inhibitory effects on both the slow calcium and fast sodium inward currents in myocardial and vascular smooth muscle, interferes with calcium binding to calmodulin, and blocks both voltage and receptor operated calcium channels. It is used to treat hypertension (high blood pressure), angina (chest pain), sustained atrial fibrillation and tachyarrhythmia. The most common side effects were upper gastrointestinal complaints (nausea, dyspepsia or GI distress), diarrhea, dizziness, asthenia and nervousness. Certain drugs could increase the likelihood of potentially serious adverse effects with bepridil hydrochloride. In general, these are drugs that have one or more pharmacologic activities similar to bepridil hydrochloride, including anti-arrhythmic agents such as quinidine and procainamide, cardiac glycosides and tricyclic anti-depressants. Anti-arrhythmics and tricyclic anti-depressants could exaggerate the prolongation of the QT interval observed with bepridil hydrochloride. Cardiac glycosides could exaggerate the depression of AV nodal conduction observed with bepridil hydrochloride.

Bepridil is a calcium channel blocker that has well characterized anti-anginal properties and known but poorly characterized type 1 anti-arrhythmic and anti-hypertensive properties. It has inhibitory effects on both the slow calcium and fast sodium inward currents in myocardial and vascular smooth muscle, interferes with calcium binding to calmodulin, and blocks both voltage and receptor operated calcium channels. It is used to treat hypertension (high blood pressure), angina (chest pain), sustained atrial fibrillation and tachyarrhythmia. The most common side effects were upper gastrointestinal complaints (nausea, dyspepsia or GI distress), diarrhea, dizziness, asthenia and nervousness. Certain drugs could increase the likelihood of potentially serious adverse effects with bepridil hydrochloride. In general, these are drugs that have one or more pharmacologic activities similar to bepridil hydrochloride, including anti-arrhythmic agents such as quinidine and procainamide, cardiac glycosides and tricyclic anti-depressants. Anti-arrhythmics and tricyclic anti-depressants could exaggerate the prolongation of the QT interval observed with bepridil hydrochloride. Cardiac glycosides could exaggerate the depression of AV nodal conduction observed with bepridil hydrochloride.

Pinacidil is a clinically effective vasodilator used for the treatment of hypertension.

Penbutolol is a new beta-adrenergic blocking drug approved for the treatment of hypertension. It is a noncardioselective beta-blocker and has intrinsic sympathomimetic activity. Penbutolol is marketed under the trade names Levatol, Levatolol, Lobeta, Paginol, Hostabloc, Betapressin. Penbutolol acts on the β1 adrenergic receptors in both the heart and the kidney. When β1 receptors are activated by catecholamines, they stimulate a coupled G protein that leads to the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). The increase in cAMP leads to activation of protein kinase A (PKA), which alters the movement of calcium ions in heart muscle and increases the heart rate. Penbutolol blocks the catecholamine activation of β1 adrenergic receptors and decreases heart rate, which lowers blood pressure. Levatol (Penbutolol) is indicated in the treatment of mild to moderate arterial hypertension. It may be used alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.

Encainide is an antiarrhythmic drug, developed by Bristol Myers Co supplied 25 and 35 mg capsules for oral administration. Encainide is no longer used because of its frequent proarrhythmic side effects. The mechanisms of the antiarrhythmic effects of Enkaid are unknown but probably are the result of its ability to slow conduction, reduce membrane responsiveness, inhibit automaticity, and increase the ratio of the effective refractory period to action potential duration. Enkaid produces a differentially greater effect on the ischemic zone as compared with normal cells in the myocardium. This could result in the elimination of the disparity in the electrophysiologic properties between these two zones and eliminate pathways of abnormal impulse conduction, development of boundary currents and/or sites of abnormal impulse generation. The absorption of Enkaid after oral administration is nearly complete with peak plasma levels present 30 to 90 minutes after dosing. There are two major genetically determined patterns of encainide metabolism. In over 90% of patients, the drug is rapidly and extensively metabolized with an elimination half-life of 1 to 2 hours. These patients convert encainide to two active metabolites, O-demethylencainide (ODE) and 3-methoxy-O-demethylencainide (MODE), that are more active (on a per mg basis) than encainide itself. In less than 10% of patients, metabolism of encainide is slower and the estimated encainide elimination half-life is 6 to 11 hours. Slow metabolism of encainide is associated with a diminished ability to metabolize debrisoquin. Enkaid should be administered only after appropriate clinical assessment and the dosage of Enkaid must be individualized for each patient on the basis of therapeutic response and tolerance. The recommended initial dosing schedule for adults is one 25 mg Enkaid capsule t.i.d. at approximately 8-hour intervals.

Niclosamide is an antihelminth used against tapeworm infections. It may act by the uncoupling of the electron transport chain to ATP synthase. The disturbance of this crucial metabolic pathway prevents creation of adenosine tri-phosphate (ATP), an essential molecule that supplies energy for metabolism. Niclosamide works by killing tapeworms on contact. Adult worms (but not ova) are rapidly killed, presumably due to uncoupling of oxidative phosphorylation or stimulation of ATPase activity. The killed worms are then passed in the stool or sometimes destroyed in the intestine. Niclosamide may work as a molluscicide by binding to and damaging DNA. Niclosamide is used for the treatment of tapeworm and intestinal fluke infections: Taenia saginata (Beef Tapeworm), Taenia solium (Pork Tapeworm), Diphyllobothrium latum (Fish Tapeworm), Fasciolopsis buski (large intestinal fluke). Niclosamide is also used as a molluscicide in the control of schistosomiasis. Niclosamide was marketed under the trade name Niclocide, now discontinued.

Zomepirac Sodium (Zomax) is a pyrrole-acetic acid structurally related to tolmetin sodium. Zomepirac is a prostaglandin synthetase inhibitor and is not an opioid, an opioid antagonist, or a salicylate. Zomepirac was approved by the Food and Drug Administration for marketing in the United States as an analgesic. It was indicated for all forms of mild to moderately severe pain, and was being promoted as a "comprehensive, non-addicting analgesic." Later Zomepirac was found to be associated with fatal and near-fatal anaphylactoid reactions. The manufacturer voluntarily removed Zomax tablets from the Canadian, US, and UK markets in March 1983.

Maprotiline is a tetracyclic antidepressant with similar pharmacological properties to tricyclic antidepressants (TCAs). Similar to TCAs, maprotiline inhibits neuronal norepinephrine reuptake, possesses some anticholinergic activity, and does not affect monoamine oxidase activity. It differs from TCAs in that it does not appear to block serotonin reuptake. Maprotiline may be used to treat depressive affective disorders, including dysthymic disorder (depressive neurosis) and major depressive disorder. Maprotiline is effective at reducing symptoms of anxiety associated with depression. The mechanism of action of maprotiline is not precisely known. It does not act primarily by stimulation of the central nervous system and is not a monoamine oxidase inhibitor. The postulated mechanism of maprotiline is that it acts primarily by potentiation of central adrenergic synapses by blocking reuptake of norepinephrine at nerve endings. This pharmacologic action is thought to be responsible for the drug’s antidepressant and anxiolytic effects. The mean time to peak is 12 hours. The half-life of elimination averages 51 hours.

Zomepirac Sodium (Zomax) is a pyrrole-acetic acid structurally related to tolmetin sodium. Zomepirac is a prostaglandin synthetase inhibitor and is not an opioid, an opioid antagonist, or a salicylate. Zomepirac was approved by the Food and Drug Administration for marketing in the United States as an analgesic. It was indicated for all forms of mild to moderately severe pain, and was being promoted as a "comprehensive, non-addicting analgesic." Later Zomepirac was found to be associated with fatal and near-fatal anaphylactoid reactions. The manufacturer voluntarily removed Zomax tablets from the Canadian, US, and UK markets in March 1983.