ALBENZA (albendazole) is an orally administered anthelmintic drug. Chemically, it is methyl 5¬ (propylthio)-2-benzimidazolecarbamate, is indicated to treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium. In addition, treatment of cystic hydatid disease of the liver, lung, and peritoneum, caused by the larval form of the dog tapeworm, Echinococcus granulosus. Albendazole binds to the colchicine-sensitive site of β-tubulin inhibiting their polymerization into microtubules. The decrease in microtubules in the intestinal cells of the parasites decreases their absorptive function, especially the uptake of glucose by the adult and larval forms of the parasites, and depletes glycogen storage. Insufficient glucose results in insufficient energy for the production of adenosine trisphosphate (ATP) and the parasite eventually dies. Albendazole developed in 1975. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. The incidence of side effects reported in the published literature is very low, with only gastrointestinal side effects occurring with an overall frequency of just >1% . Albendazole's unique broad-spectrum activity is exemplified in the overall cure rates calculated from studies employing the recommended doses for hookworm (78% in 68 studies: 92%, for A. duodenale in 23 studies and 75% for N. americanus in 30 studies), A. lumbricoides (95% in 64 studies), T. trichiura (48% in 57 studies), E. vermicularis (98% in 27 studies), S. stercoralis (62% in 19 studies), H. nana (68% in 11 studies), and Taenia spp. (85% in 7 studies).

Praziquantel, marketed as Biltricide, is an anthelmintic used in humans and animals for the treatment of tapeworms and flukes. Specifically, it is effective against schistosoma, Clonorchis sinensis the fish tape worm Diphyllobothrium latum. Praziquantel works by causing severe spasms and paralysis of the worms' muscles. This paralysis is accompanied - and probably caused - by a rapid Ca 2+ influx inside the schistosome. Morphological alterations are another early effect of praziquantel. These morphological alterations are accompanied by an increased exposure of schistosome antigens at the parasite surface. The worms are then either completely destroyed in the intestine or passed in the stool. An interesting quirk of praziquantel is that it is relatively ineffective against juvenile schistosomes. While initially effective, effectiveness against schistosomes decreases until it reaches a minimum at 3-4 weeks. Effectiveness then increases again until it is once again fully effective at 6-7 weeks. Glutathione S-transferase (GST), an essential detoxification enzyme in parasitic helminths, is a major vaccine target and a drug target against schistosomiasis. Schistosome calcium ion channels are currently the only known target of praziquantel. The antibiotic rifampicin decreases plasma concentrations of praziquantel. Carbamazepine and phenytoin are reported to reduce the bioavailability of praziquantel. Chloroquine reduces the bioavailability of praziquantel. The drug cimetidine heightens praziquantel bioavailability.

Mebendazole, known as Emverm is a (synthetic) broad-spectrum anthelmintic that acts by interfering with carbohydrate metabolism and inhibiting polymerization of microtubules. The loss of the cytoplasmic microtubules leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Due to diminished energy production, the parasite is immobilized and eventually dies. Emverm tablets are used for the treatment of Enterobius vermicularis (pinworm), Trichuris trichiura (whipworm), Ascaris lumbricoides (common roundworm), Ancylostoma duodenale (common hookworm), Necator americanus (American hookworm) in single or mixed infections. All metabolites are devoid of anthelmintic activity. In man, approximately 2% of administered mebendazole is excreted in urine and the remainder in the feces as unchanged drug or a primary metabolite. Preliminary evidence suggests that cimetidine inhibits mebendazole metabolism and may result in an increase in plasma concentrations drug. Mebendazole sometimes causes diarrhea, abdominal pain, and elevated liver enzymes. In rare cases, it has been associated with a dangerously low white blood cell count, low platelet count, and hair loss, with a risk of agranulocytosis in rare cases

Dexamethasone acetate (NEOFORDEX®) is the acetate salt form of dexamethasone, which is a synthetic glucocorticoid; it combines high anti-inflammatory effects with low mineralocorticoid activity. At high doses (e.g. 40 mg), it reduces the immune response. Dexamethasone acetate (NEOFORDEX®) is indicated in adults for the treatment of symptomatic multiple myeloma in combination with other medicinal products. Dexamethasone has been shown to induce multiple myeloma cell death (apoptosis) via a down-regulation of nuclear factor-κB activity and an activation of caspase-9 through second mitochondria-derived activator of caspase (Smac; an apoptosis promoting factor) release. Prolonged exposure was required to achieve maximum levels of apoptotic markers along with increased caspase-3 activation and DNA fragmentation. Dexamethasone also down-regulated anti apoptotic genes and increased IκB-alpha protein levels. Dexamethasone apoptotic activity is enhanced by the combination with thalidomide or its analogues and with proteasome inhibitor (e.g. bortezomib).

Oxamniquine is an anthelmintic with schistosomicidal activity against Schistosoma mansoni, but not against other Schistosoma spp. Oxamniquine is a potent single-dose agent for treatment of S. mansoni infection in man, and it causes worms to shift from the mesenteric veins to the liver, where the male worms are retained; the female worms return to the mesentery, but can no longer release eggs. Oxamniquine is a semisynthetic tetrahydroquinoline and possibly acts by DNA binding, resulting in contraction and paralysis of the worms and eventual detachment from terminal venules in the mesentry, and death. Its biochemical mechanisms are hypothesized to be related to an anticholinergic effect, which increases the parasite’s motility, as well as to synthesis inhibition of nucleic acids. Oxamniquine acts mainly on male worms, but also induces small changes on a small proportion of females. Like praziquantel, it promotes more severe damage of the dorsal tegument than of the ventral surface. The drug causes the male worms to shift from the mesenteric circulation to the liver, where the cellular host response causes its final elimination. The changes caused in the females are reversible and are due primarily to the discontinued male stimulation rather than the direct effect of oxamniquine

Diethylcarbamazine is used in humans, dogs and cats for the treatment of parasitic infections, including pulmonary eosinophilia, loiasis, and lymphatic filariasis. The exact mechanism of its action is unknown, however some studies showed the involvment of inducible nitric-oxide synthase and the cyclooxygenase pathway. Although there is no information on whether the drug is marketed in the USA and Europe, it is currently used in India.

Trichlorfon (Metrifonate), the organophosphorous cholinesterase inhibitor, O,O-dimethylhydroxy-2,2,2-trichlorethyl-phosphonate, has been used sporadically in the treatment of human schistosomiasis for a decade. It has selective and variable schistosomicidal activity against S. haematobium that results from its partial metabolism to a highly active anti-cholinesterase, dichlorvos. Schistosomal cholinesterase is more susceptible to this metabolite than that of the human host, but transient reductions in both plasma and erythrocyte cholinesterase activity are demonstrable at therapeutic dosage. However, despite early concerns about its potential toxicity, metrifonate is well tolerated and has been used effectively and extensively in large-scale control programmes. Its potential to enhance central nervous system cholinergic neurotransmission led to clinical trials for the treatment of people with Alzheimer's disease (AD).

Piperazine, a six membered nitrogen containing heterocycle, is of great significance to the rational design of drugs. This moiety can be found in a plethora of well-known drugs with various therapeutic uses, such as antipsychotic, antihistamine, antianginal, antidepressant, anticancer, antiviral, cardio protectors, anti-inflammatory, and imaging agents. Slight modification to the substitution pattern on the piperazine nucleus facilitates a recognizable difference in the medicinal potential of the resultant molecules. Piperazine has been used as an antihelmintic drug. Piperazine works by paralyzing the worms. They are then passed in the stool.