2 Helminths Worm classified as a parasite Contaminate food, water, air, feces, pets, wild animals, toilet seats and door handlesPrevention:Frequent hand washingFrequent cleaning of bathrooms and kitchensThorough cooking of beef, pork, sausage, and bear meat.
3 Common helminths Roundworm Hatch/live in intestines Symptoms fatigue, Weight losIrritabilityPoor appetiteAbdominal painDiarrheaUntreatedAnemiamalnutrition
4 Common helminths Trichina spiralis (trichinosis) Ingested via undercooked pork, sausage, or bear meatSpread throughout bloodstream and lymphatic systemSymptomsVomitingDiarrheaMuscle crampsUntreatedPenetration of muscles, heart, and brainDeath
5 Common helminths Tapeworms Ingested via undercooked beef Live in intestinesSymptomsUsually absentMay include abdominal pain, fatigue, weight loss, diarrhea
6 Pinworms AKA: seatworms or threadworms Most common in US 42 million peopleMostly children aged 5-14 yearsCommonly institutional settings such as child care facilities, hospitals, or family membersOnly helminthic infection with approved OTC treatment
7 Pinworm transmissionEmbryonated eggs are on clothes, bedding, bathroom fixtures or dust.Embryonated eggs are ingested (fingersucking is considered a source of infection).Reinfection occurs by direct anus to mouth transfer, with eggs found under fingernails of children who have scratched the anal area.
8 Pinworm lifecycle 1. Adult males and females inhabit ileocecum. 2. Female migrates out of anus and deposits eggs in perianal region then dies.3. Eggs hatch within a few hours and larvae return to large intestine via anus (retroinfection), crawl into genitourinary tract, or eggs are reingested by the host.
9 Clinical presentation and complications Frequently asymptomaticMost frequent symptom: nighttime perianal itchingAlso: abdominal pain, insomia, restlessness, anorexia, diarrheaLess common: vaginitis, PID, dysuria, and UTI, leading to infertilityBacterial infections secondary to itching
10 Diagnosing Pinworms Visual inspection Cellophane tape sample With a flashlight, inspect the anal area during early morning hours while child is asleepCellophane tape sampleUsing a tongue depressor, apply the sticky side of a piece of tape to the perianal area and then to a glass slide, sticky side down. Commercial kits are available. The sample undergoes microscopic examination by a physician.
11 Prescription therapy Mebendazole (Vermox): Adult / pediatric > 2yrs: 100mg x 1 doseRepeat in 2 weeks if symptoms do not resolveIndications: roundworm, pinworm, hookworm, trichinosis, some tapewormsMOA: blocks glucose uptake by parasite until death ensuesPrecautions:Pregnancy (category C) – animal studies showed teratogenic effectsBreast feeding – excretion into breast milk is unknownHepatic disease (eliminated by liver)Inflammatory bowel disease
12 Prescription Therapy Alternative: Albendazole (Albenza) Dosing Adult/peds >2 yrs: 400mg x 1 doseMay repeat in 3 weeksMOA: same as mebendazolePrecautions:Liver dysfunction or biliary tract diseaseMay cause bone marrow dysfunctionPregnancy Cat. C – animal studies showed teratogenic effectsBreast feeding – not recommended due to lack of clear data
13 Non-rx therapy Pyrantel Used in veterinary practice for pinworms, roundworms, and hookwormsMOA: depolarizing neuromuscular agentPoorly absorbed; 50% excreted unchanged in fecesDosing: Single dose of 11mg/kg for adults & pedsMax single dose = 1gmSame dosing for children < 2yrs or <25#, but must first check with physician2nd dose may be required in 2 weeksMay be taken without regards to mealsSide effectsGI tract: N,V,D, abdominal crampsLess common: headache, dizziness, drowsiness, rash, fever, weakness
14 Non-rx therapy Pyrantel Precautions/contraindications Hypersensitivity to the drugPre-existing liver dysfunction or severe malnutritionPregnancy category C – use only under direction of physician (animal studies have revealed no harmful effects)Breastfeeding – poorly absorbed low concentrations in breast milkChildren < 2 years of age or weighing <25#, use only under direction of physician
15 CaseA father presents to the pharmacy requesting OTC pinworm therapy for his 2 year old son. His 4 year old daughter was recently diagnosed with pinworms and was given a prescription for mebendazole. The physician recommended OTC therapy for the son, who is experiencing night-time perianal itching.What are the potential exclusions for self treatment?
16 Case (con’t)What is the appropriate dose for the son?
17 Case (con’t)What additional patient counseling points should be made?