2bmtgroup5-blog

[2bmtgroup5-blog]

ALBENDAZOLE (nematodes)

Brand name:  Hyemex

Indications: Used to treat tapeworm infections such as neurocysticercosis and hydatid disease (Echinococcosis)

Dosage and Dosage details:

Echinococcosis

For adults and children who are <60 kg take 15 mg/kg daily in 2 divided doses. A maximum of 800 mg/day

For adults and children who are ≥60 kg take 400 mg bid. Admin dose for three 28 day cycles with a 14 day drug free interval in between each cycle.

Neurocysticercosis

For adults and children <60 kg take 15 mg/kg daily in 2 divided doses, with a maximum of 800 mg/day, for 8-30 days

For adults and children ≥60 kg take 400 mg bid for 8-30 days

Administration: Oral and should be taken with food

Special precautions

Patients with renal lesions

Patients treated for neurocysticercosis is required to receive an appropriate steroid and anticonvulsant therapy

Pregnancy and lactation

Adverse side effects:

Headache and dizziness

increased intracranial pressure

Fever

Vertigo

Meningeal signs

Alopecia

Abdominal pain, nausea and vomiting

hypersensitivity reactions including rash and urticaria

Elevation of hepatic enzymes

Hepatitis

Acute liver and renal failure

Erythema multiforme

Stevens-Johnson syndrome

Potentially Fatal due to bone marrow suppression which leads to pancytopenia, aplastic anaemia, agranulocytosis, and leukopenia

Half-life:

Terminal elimination half-life with a 400 mg single dose, ranges from 8 to 12 hours

Plasma half-life: Approximately  8.5 hours

Monitoring Parameters:

Monitor fecal specimens (ova and parasites) for 3 weeks after the treatment

LFTs, CBC (with differential), and Ophth exam for patients with Neurocysticercosis

Pharmacokinetics & MOA:

Causes selective degeneration of cytoplasmic microtubules in intestinal and tegmental cells of intestinal helminths and larvae

Glycogen is depleted

Glucose uptake and cholinesterase secretion are impaired and desecratory substances accumulate intracellularly

ATP production decreases, causing energy depletion, immobilisation and worm death

Undergoes extensive hepatic first-pass metabolism and is then converted to albendazole sulfoxide

Mainly excreted through the bile, but some small amounts is excreted through urine

Absorption:

Poorly absorbed from the GI tract due to low aqueous solubility

Absorption may be enhanced by a fatty meal

2 to 5 hours to achieve peak plasma concentration

Drug interactions:

Increased serum concentrations with dexamethasone, praziquantel and cimetidine.

Decreased serum concentrations w/ aminoquinoline (antimalarials), carbamazepine, phenobarbital, and phenytoin.

Food Interaction:

Increased serum levels w/ a fatty meal

Grapefruit juice may increase serum concentrations of albendazole

Sources:

Cunha, J. P. (2017, July 26). Albendazole: Side Effects, Dosages, Treatment, Interactions, Warnings. Retrieved 9 May 2019 from https://www.rxlist.com/consumer_albendazole_albenza/drugs-condition.htm#what_are_warnings_and_precautions_for_albendazole

Drug Bank. (2005, June 13). Albendazole. Retrieved 9 May 2019 from https://www.drugbank.ca/drugs/DB00518

MIMS. (n.d.). Albendazole. Retrieved 9 May 2019 from https://www.mims.com/philippines/drug/info/albendazole?mtype=generic

[2bmtgroup5-blog]

DIETHYLCARBAMAZINE (roundworms/filaria)

Brand names:

Filarizide

Banocide

Decet

Dec-P

Dicarb

Hetrazan

Notezine

Indications:

Used for the treatment of loiasis caused by Loa loa

Used for the treatment of lymphatic filariasis, caused by the parasites such as Wuchereria bancrofti or Brugia malayi

Dosage and Dosage details

Filariasis, Loiasis, Toxocariasis (Oral): 1 mg/kg daily, increased gradually to 6 mg/kg daily over 3 days and maintained for 3 weeks. A corticosteroid may be given concurrently for the treatment of filarial infections.

Prophylaxis of Loiasis (Oral) : 300 mg weekly

Administration: Oral, Topical, Optical

Contraindication: Pregnancy, Lactation, Hypersensitivity, Infants, Elderly, Debilitated patients, Impaired renal function, Cardiac disease

Special precautions

Patients with poor health

Adverse side effects

Fever

Headache

Nausea and Vomiting

Drowsiness

Chills

Potentially Fatal

Encephalitis

Retinal Hemorrhage

Mazzotti Reaction:

Severe hypersensitivity

Characterized by rashes, itching, headaches, muscle and joint pains, tachycardia, and postural hypotension (may start within 2 hours after taking the drug)

Half-life: 10 to 12 hours

Pharmacokinetics & MOA

Immobilizes microfilariae and alters their surface structure, displacing them from tissues and making them more susceptible to eradication by host defense mechanisms.

Well absorbed following oral administration with peak plasma concentrations reached within 1-2 hours

Excreted in the urine

Absorption is in the GI tract for oral, skin for topical, and conjunctiva for optical

Widely distributed in tissues

Sources

Antimicrobe.org. (n.d.). Diethylcarbamazine. Retrieved May 9, 2019, from http://www.antimicrobe.org/drugpopup/Diethylcarbamazine.html

Drugs.com. (n.d.). Diethylcarbamazine. Retrieved May 9, 2019, from https://www.drugs.com/international/diethylcarbamazine.html

MIMS. (n.d.). Diethylcarbamazine. Retrieved May 9, 2019, from https://www.mims.com/philippines/drug/info/diethylcarbamazine?mtype=generic

Rosenthal, P. (2017). Clinical Pharmacology of the Antihelminthic Drugs. In B.G. Katzung (Ed.), Basic & Clinical Pharmacology (pp. 938-947). New York, NY: McGraw-Hill.

[2bmtgroup5-blog]

IVERMECTIN (threadworms)

Brand name:  Stromectol  

Indications: For treatment of strongyloidiasis (Strongyloides stercoralis) and onchocerciasis (Onchocerca volvulus)

Dosage:

Onchocerciasis (Oral)

Single dose of ivermectin, 150 mcg/kg, with water on an empty stomach

After acute therapy, treatment is repeated at a 12-month interval until the adult worm dies

Adult: 150 mcg/kg as single dose; repeat treatment every 3-12 mth until symptoms resolved

Child: ≥15 kg: Same as adult dose

Strongyloidiasis (Oral)

Adult: 200 mcg/kg for 1-2 days

Child: ≥15 kg: Same as adult dose

Head pediculosis (Topical/Cutaneous) 

Adult: As 0.5% lotion: Apply sufficient amount into dry hair and scalp as single dose, then leave on for 10 min before rinsing

Child: ≥6 mth Same as adult dose

Administration: Should be taken on an empty stomach

Special precautions:

Patient with onchocerciasis and loiasis

Immunocompromised patients

Children

Pregnancy and lactation

Adverse side effects:

Mazzotti reaction (e.g. oedema, pruritus, arthralgia, synovitis, fever, sore throat, cough, headache, tachycardia, orthostatic hypotension, oedema)

Dizziness, asthenia, fatigue, somnolence, vertigo, tremor

Diarrhoea, abdominal pain, nausea, anorexia, constipation, vomiting

Dermatologic: Burning sensation, irritation, itch, dry skin, contact dermatitis, erythema (topical)

Half-life: 16 hours

Pharmacokinetics & MOA:

Ivermectin is a semisynthetic anthelmintic. It selectively binds to glutamate gated Cl ion channels which results to increased permeability of cell membranes to Cl ions leading to hyperpolarization of the nerve or muscle cell causing death of the parasite.

Rapidly absorbed

Reaches maximum plasma concentrations 4 hours after a 12-mg dose

Wide tissue distribution

Volume of distribution is 50L

Excretion of the drug and its metabolites is almost exclusively in the feces

Drug interactions

Enhanced anticoagulant effect of Vitamin K antagonists (e.g. warfarin)

Diminished therapeutic effect of lactobacillus and estriol

Sources:

Rosenthal, P. (2017). Clinical Pharmacology of the Antihelminthic Drugs. In B.G. Katzung (Ed.), Basic & Clinical Pharmacology (pp. 938-947). New York, NY: McGraw-Hill.

MIMS (n.d.). Ivermectin. Retrieved 14 May 2019 from https://www.mims.com/philippines/drug/info/ivermectin/?type=brief&mtype=generic

[2bmtgroup5-blog]

PYRANTEL (nematodes)

Brand name:  Combantrin

Indications:  For the treatment of enterobiasis (pinworm infection), ascariasis (roundworm), uncinariasis (hookworm infection), and trichostrongyliasis

Dosage:

Hepatic impairment

Renal impairment

For the treatment of enterobiasis (oral dosage)

Adults

11 mg/kg base PO as single dose

Retreatment may be necessary after 14 to 21 days

Treatment of entire household is recommended

Children 2 years and older weighing 11 kg or more and Adolescents (oral dosage)

11 mg/kg base PO as single dose

Retreatment may be necessary after 14 to 21 days

Treatment of entire household is recommended

Children 2 years and older weighing less than 11 kg (oral dosage)

11 mg/kg base PO as single dose

Retreatment may be necessary after 14 to 21 days

Treatment of entire household is recommended

Consult physician

Infants and children 1 year (oral dosage) 

11 mg/kg base PO as single dose

Retreatment may be necessary after 14 to 21 days

Treatment of entire household is recommended

Consult physician

For the treatment of ascariasis

Adults (oral dosage)

11 mg/kg base PO once daily for 3 days

Alternative to albendazole or mebendazole

Infants, children, and adolescents (oral dosage) 

11 mg/kg base PO once daily for 3 days

Alternative to albendazole or mebendazole

For the treatment of uncinariasis

Adults (oral dosage)

11 mg/kg base PO once daily for 3 days

Infants, children, and adolescents (oral dosage)

11 mg/kg base PO once daily for 3 days

For the treatment of trichostrongyliasis

Adults, infants, children, and adolescents (oral dosage)

11 mg/kg base PO as single dose

Administration:

Oral administration

Oral liquid formulations

May be taken with or without food

Contraindication*

Hepatic disease

Phenylketonuria

Pregnancy

Breast-feeding

Adverse side effects

Vomiting

Abdominal pain

Nausea

Diarrhea

Dizziness

Headache

Half-life: In pigs, its half-life is 1.75 +/- 0.19 h

Pharmacokinetics & MOA

Minimally absorbed from the GI tract (oral)

Excretion via urine (7% as unchanged drug and metabolites) and via feces (>50% as unchanged)

Acts as a depolarizing neuromuscular blocking agent in helminths by stimulating the release of acetylcholine, inhibiting cholinesterase, and stimulating ganglionic neurons. Tension of the helminth’s muscles is then caused by these actions which cause extensive depolarization of the helminth muscle membrane. Tension causes paralysis and release of their hold to the intestinal wall. The expulsion of the parasites from the GI tract occurs by normal peristalsis.

Drug interactions: Mutually antagonistic with piperazine (potentially fatal)

Sources:

MIMS (n.d.). Pyrantel. Retrieved 11 May 2019 from https://www.mims.com/philippines/drug/info/pyrantel/?type=brief&mtype=generic

PDR Search (n.d.). Retrieved 11 May 2019 from https://www.pdr.net/drug-summary/Pin-X-Chewable-Tablets-pyrantel-pamoate-2670

Pyrantel (n.d.). Retrieved 11 May 2019 from https://www.drugbank.ca/drugs/DB11156

IBM Micromedex (2019). Pyrantel (Oral Route). Retrieved 11 May 2019 from https://www.mayoclinic.org/drugs-supplements/pyrantel-oral-route/description/drg-20065667

[2bmtgroup5-blog]

MEBENDAZOLE (nematodes)

Brand name: Vermox

Indications: For the treatment of Enterobius vermicularis (pinworm), Trichuris trichiura (whipworm), Ascaris lumbricoides (common roundworm)

Dosage:

Chewable Tablet: 100 mg, round, flat radius-edged white to yellowish chewable tablet that is debossed with “M/100” on one side and “J” on the other side

Pinworm (Enterobius vermicularis)

Adults: 100 mg PO as a single dose. If cure is not achieved 3 wk after treatment, a second course of treatment is advised

Pediatric: <2 years: Safety and efficacy not established

Roundworm (Ascaris lumbricoides)

Adults:  500 mg PO as a single dose

Pediatric: <1 year: Safety and efficacy not established;  ≥1 year: 500 mg PO as a single dose

Whipworm (Trichuris trichiura)

Adults: 500 mg PO as a single dose

Pediatric: <1 year: Safety and efficacy not established; ≥1 year: 500 mg PO as a single dose

Administration:

Oral

May take with or without food

Chew tablet completely before swallowing, do not swallow tablet whole

Tablet can be placed in a spoon with ~2-3 mL of drinking water added onto the tablet using a dosing syringe

Within 2 minutes, the tablet absorbs the water and turns into a soft mass with semi solid consistency, which can then be swallowed

Special precautions

Before taking mebendazole, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems.

Tell your doctor your medical history, especially of: low blood count (anemia), liver disease, intestinal problems (e.g., Crohn's disease, ulcerative colitis).

During pregnancy, this medication should be used only when clearly needed.

Adverse side effects:  stomach/abdominal pain, vomiting, diarrhea, headache, dizziness, or drowsiness

Half-life:  3–6 hours

Pharmacokinetics & MOA:  Inhibitory effect on tubulin polymerization which results in the loss of cytoplasmic microtubules

Drug interactions:

Decreased plasma concentrations w/ carbamazepine and phenytoin

Increased plasma concentrations w/ cimetidine.

Sources:

Drugs.com. (2019). Mebendazole Drug Interactions - Drugs.com. Retrieved May 11, 2019, from https://www.drugs.com/drug-interactions/mebendazole.html

Mebendazole and Vermox. (2017). Vermox (Mebendazole): Side Effects, Interactions, Warning, Dosage & Uses. Retrieved May 11, 2019, from https://www.rxlist.com/vermox-drug.htm#side_effects

MIMS (n.d.). Mebendazole. Retrieved 11 May 2019 from https://www.mims.com/philippines/drug/info/mebendazole/?type=brief&mtype=generic

[2bmtgroup5-blog]

PRAZIQUANTEL (cestodes, trematodes)

Brand Name: Fluxide

Used for Treatment of:

Schistosomiasis, Clonorchiasis, Opisthorchiasis, Paragonimiasis,  fasciolopsiasis

Doseage:

Clonorchiasis, fasciolopsiasis, paragonimiasis, opisthorchiasis (Oral)

Adult: 25 mg/kg tid at intervals of 4-6 hour for 1-2 days or 40 mg/kg as a single dose

Child (≥4 years old): Same as adult dose

Schistosomiasis (Oral)

Adult: 20 mg/kg 4-6 hourly for 3 doses or 40-60 mg/kg as a single dose

Child (≥4 years old): Same as adult dose

Administration:  Taken with food

Contraindication:

Ocular cysticercosis

Concomitant admin of strong CYP inducers

Lactation

Special Precautions:

Pregnancy

Patient with cardiac abnormalities, cerebral cysticercosis, history of epilepsy and/or other signs of potential CNS involvement

Moderate to severe hepatic impairment

Adverse Side effects

Headache, drowsiness, dizziness, lassitude

Nausea, vomiting, diarrhoea, myalgia, malaise, abdominal discomfort, urticaria, rash, fever, asthenia, fatigue,

Rare: raised liver enzyme values, seizures, eosinophilia, pruritus

Half Life: 0.8 to 1.5 hrs

Pharmacokinetics & MOA:

Increases the permeability of trematode and cestode cell membranes to calcium → results in paralysis, dislodgement, and death

Synthetic isoquinoline-pyrazine derivative

Rapidly absorbed, with a bioavailability of 80% after oral administration

Peak serum concentrations are reached 1-3 hours after a therapeutic dose

Rapidly metabolized after a first pass in the liver

Excretion is mainly via the kidneys (60–80%) and bile (15–35%)

Drug interactions:

CYP enzyme-inducing drugs (carbamazepine, dexamethasone, phenobarbital, phenytoin, etc.) may decrease plasma concentrations of praziquantel

Intake along with rifampicin may cause subtherapeutic concentrations of praziquantel and can potentially be fatal

Sources:

Rosenthal, P. (2017). Clinical Pharmacology of the Antihelminthic Drugs. In B.G. Katzung (Ed.), Basic & Clinical Pharmacology (pp. 938-947). New York, NY: McGraw-Hill.

MIMS (n.d.). Praziquantel. Retrieved 12 May 2019 from https://www.mims.com/philippines/drug/info/praziquantel/?type=brief&mtype=generic