Anti Helminthic Drugs

ANTIHELMINTIC DRUGS Roundworms

A. LUMBRICOIDES VERMICULARIS ROUNDWORM

N. AMERICANUS HOOKWORM

E. PINWORM

T. TRICHURA WHIPWORM

S. STERCORALIS THREADWORM

DRUGS THAT ACT AGAINST NEMATODES A. ALBENDAZOLE MECH OF ACTION – blocks glucose uptake in both larval and adult parasite , which leads to decrease formation of atp - inhibition of microtubule assembly CLINICAL USE : broad anthelintic spectrum first drug of choice for larve migrans( ancylostoma spc) alternative drug for roundworms , whipworm, hookworms,pinworms and threadworm TOXICITY : reversible leukopenia , alopecia and changes in the liver anzymes LONG TERM USE : bone marrow suppresion and fetal toxicity B. DITHYLCARBAMAZINE MECHANISM OF ACTION : immobilizes microfilariae CLINICAL USE: drug of choice for filariasis alternative for onchocerciasis ( in combination with suramin) TOXICITY : headache, malaise, weakness, anorexia  can cause the mazzotti reaction in onchocerciasis – hypotension, pyrexia respiratory distress and prostration fever, rashes and ocular damage

Tissue Nematodes

ONCHOCERCA bancrofti

ANCYCLOSTOMA

Wuchereria

C. IVERMECTIN MECHANISM OF ACTION : intesifies gaba mediated neurotransmission in nematodes resulting to paralysis CLINICAL USE : drug of choice for onchocerciasis : drug of first choice for strongloidiasis and alternative drug for filariasis TOXICITY : fever, headache ,dizziness ,rashes, pruritus, tachycardia ,hypotension , joint pains , muscle [ain and pain ion lymph nodes D. MEBENDAZOLE MECHANISM OF ACTION – selctively inhibit microtubule syntheisi and glucose uptake in nematodes CLINICAL USE :  drug of first choice for pinworms , whipworms and round worms  second drug of choice for cestodes nad trematode infection

TOXICITY : only limited to gastrointestinal irritation . embyrotoxic E. PIPERAZINE MECH. OF ACTION – acting as agonist at gaba recptors CLINICAL USE ; drug of choice for ascariasis TOXICITY : git irritation F. PYRANTEL PAMOATE MECH OF ACTION – pyrantel pamoate and its congener axantel pamoate, stimulate nicotinic receptor present at tne neuromuscular junctions of nematodes. contraction of muscle occurs ,followed by a depolarizarion induced paralysis CLINICAL USE : ( along with mebendazole) drug of choice for hookworm, pinworm and roundworm infestation . TOXICITY - git distress ,headache and weakness

CLINICAL USE : drug of choice for schistosomiasis, clornorchiasis and paragonimiasis  it is also one of the drug of choice for cestodes TOXICITY – headache , dizziness, malaise and git irritation , skin rashes and fever CONTRAINDICATION : ocular cysticercosis B. BITHIONOL = drug of choice for the treatment of fascioliasis ( sheep liver fluke) TOXICITY : nausea , vomiting, diarrhea, abdominal cramps, dizziness, dizziness, headache , phototoxicity , pyrxia, tinnitus, proteinuria and leukopenia C. METRIFONATE – is an organophosphate prodrug that is converted in the body to cholinesterase inhibitor dichlorvos , this active metabolite acts solely against schistosoma haematobium ( the cause of bilharziasis )

TREMATODES D. OXAMNIQUINE – effective solely in schistosoma mansoni infections TOXICITY : dizziness ,git irritation , pruritus REACTION TO DYING PARASITES – eosinophilia ,urticaria and pulmonary infiltrates SCHISTOSOMA (BLOOD FLUKE )

LUNG FLUKE

DRUG THAT ACT AGAIST CESTODES (TAPEWORM)

CLONORCHIS SINENSIS(LIVER FLUKE)

DRUGS THAT ACT AGAINST TREMATODES A. PRAZIQUANTEL MECH. OF ACTION – increases membrane permeability to calcium, causing marked contraction initially and then paralysis of trematode muscles ; this is followed by vacuolization and parasite death

NICLOSAMIDE MECHANISM OF ACTION ; act by uncoupling oxidative phosphorylation or by activating atpase CLINICAL USE : effective in beef, pork and fish tapeworm but not in cysticercosis ( albendazole or prqaziquatel is more effective) TOXICITY ; git distress ,headache, rash and fever