2Helminths 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.
4Common helminths Trichina spiralis (trichinosis) Ingested via undercooked pork, sausage, or bear meatSpread throughout bloodstream and lymphatic systemSymptomsVomitingDiarrheaMuscle crampsUntreatedPenetration of muscles, heart, and brainDeath
5Common helminths Tapeworms Ingested via undercooked beef Live in intestinesSymptomsUsually absentMay include abdominal pain, fatigue, weight loss, diarrhea
6Pinworms 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
7Pinworm 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.
8Pinworm 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.
9Clinical 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
10Diagnosing 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.
11Prescription 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
12Prescription 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
13Non-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
14Non-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
15CaseA 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?
16Case (con’t)What is the appropriate dose for the son?
17Case (con’t)What additional patient counseling points should be made?