ANTIPARASITICS Flashcards Preview

Effective in treatment of

1) strongyloidiasis caused by Strongyloides stercoralis (threadworm), (strong guy in tunnel kicking wall in on right side) 

2) CUTANEOUS LARVA MIGRANS, and

3) early stages of TRICHINOSIS 

MOA

• Affects microtubular aggregation

Pharmacokinetics

• Oral
• Nearly insoluble in H20

• MOST TOXIC of all the benzimidazoles

• Dizziness, anorexia, nausea, vomiting

• CNS disturbances (dizziness --> seizures)

• Cases of erythema multiforme & Stevens-Johnson reported

• Contraindicated in pregnancy (FDA Category C)
• Should not be used in presence of liver or kidney disease

Drug of choice for the treatment of

1) onchocerciasis (Onchocerca volvulus), (movie scene, back of the room guy covering one eye near the no dumping in river sign) 

2) cutaneous larva migrans &

3) strongyloides (in tunnel, guy on right kicking in wall) 

MOA

• GABA agonist*******
• Cl- influx increases leading to hyperpolarization of nerve /

muscle cell. Death occurs due to paralysis of parasite*****

Pharmacokinetics

• Oral (does not cross BBB)

• ***Mazotti-like reactions with onchoceriasis (fever, dizziness, somnolence, hypotension)**** --> IS D/T DEATH OF THE PARASITE

• Contraindicated in pregnancy (FDA Category C)

• Contraindicated in meningitis (may cross BBB)******

• Best to avoid concomitant use of ivermectin & other drugs that enhance GABAergic activity (eg, barbiturates, benzodiazepines)

antihelminthic drug

Alternative drug for treatment of pinworm & roundworm infections

MOA

• GABA agonist
• Expulsion of worm occurs by peristalsis

Contraindications

• Patients with seizure disorders

ANTIHELMINTHIC DRUG

Effective in treatment of infections by roundworms, pinworms and hookworms

MOA

• Acts as a depolarizing, neuromuscular-blocker (causes persistent activation of parasite’s nicotinic receptors by release of acetylcholine & inhibition of cholinesterase)

Pharmacokinetics

• Poorly absorbed orally (exerts effects in intestinal tract)

AE: 

• Mild (nausea, vomiting, diarrhea)

Drug of choice for treatment of

1) lymphatic filariasis, (WUCHERERIA BANCROFTI = “witch” --> elephantiasis)  

2) loiasis (loa loa = creepy blue worm guy, cause callabar swellings)

3) tropical eosinophilia. = WUCHERERIA BANCROFTI

MOA

• Immobilizes microfilariae & renders them susceptible to host defense mechanisms

Pharmacokinetics

• Oral (rapidly absorbed with meals)

• Most AE thought to be due to host responses following damage/death of parasite*****

• Fever, malaise, rash, myalgias, arthralgias, headache

• Leukocytosis (common)

• Antihistamines or steroids can be coadministered

• Tetracycline antibiotic.
• Macrofilaricidal activity against Wuchereria bancrofti. (witch wearing the elephant pants) 

• Also active against onchocerciasis (bug man) FOUND NEAR RIVERS at the back with no dumping sign) 

MOA

• Acts indirectly by killing Wolbachia (intracellular bacterial symbiont of filarial parasites)

•Drug of choice for all forms of schistosomiasis & most trematode & cestode infections

• Cysticercosis – albendazole is drug of choice (praziquantel has similar efficacy)

MOA

• Increases permeability of cell membrane to calcium, causing contracture & paralysis of worm musculature, resulting in detachment of suckers from blood vessel walls.

PK: 

• Oral
• Extensive first-pass metabolism (CYPs)
• Inactive metabolites excreted via urine & bile

• Drowsiness, dizziness, malaise, anorexia & GI upsets

• Drug interactions (CYP P450)

• Contraindicated in pregnancy & nursing mothers (FDA Category B)

• Contraindicated for treatment of ocular cysticercosis *******(destruction of organism may damage eye)*****

ANTIHELMINTHIC DRUG

• Drug of choice for fasciolosis (sheep liver fluke)

• Alternative drug for pulmonary paragonimiasis

MOA

• Inhibition of helminth’s electron transport chain (probably)

• 2nd line drug for treatment of most cestode infections

•Use is uncommon due to excellent efficacy of praziquantel

• No longer available in US

MOA

• Inhibition of the parasite’s mitochondrial phosphorylation of ADP. Anaerobic metabolism may also be inhibited

• Drug is lethal for cestode’s scolex & segments of cestodes but not for the ova

PK: 

• ****Laxative is admin. prior to niclosamide (oral) to purge bowel of all dead segments in order to preclude digestions & liberation of ova (may lead to cysticercosis)****

• ***Alcohol should be avoided within 1 day of dose***

• Safety has not been established in pregnancy or children <2

ASCARIS LUMRICOIDES = ROUNDWORM -->  huge lumbering tree man in back of tunnel

DOC

1) ALBENDAZOLE, 

2) PYRANTEL PAMOATE

OR

2) MEBENDAZOLE

A) ENTEROBIUS VERMICULARIS = “vermin lady” = PINWORM

--> coming out of a round hole that represents an ANUS -->  at night time the females migrate down to the anus and lay their eggs, so there are round eggs

DOC: 

1) MEBENDAZOLE 

OR

2) PYRANTEL PAMOATE 

DOC:

1) MEBENDAZOLE OR 

2) ALBENDAZOLE 

B) ANCYLOSTOMA DUODENALE + NECATOR AMERICANUS = AMERICA DUDE à both found in the rural southern USA

à rings around ankle = ancylostoma, rings around neck = necator americanus

DOC:

1) PYRANTEL PAMOATE

OR

2) MEBENDAZOLE

OR

3) ALBENDAZOLE

B) ONCHOCERCA VOLVULUS (bug man) FOUND NEAR RIVERS (sign at the back of the room) 

DOC:

1) IVERMECTIN!!!

DOC:

1) ALBENDAZOLE

2) IVERMECTIN 

D) TOXOCARA CANIS: = “wolfman”

à from contamination of food with dog or cat feces (or even wolf feces?) à can remember via the stinky poop bag that is hanging off wolf’s chair

DOC: 

1) ALBENDAZOLE

E) TRICHINELLA SPIRALIS (pig with spirals on his suit in tunnel)

à intestinal nematode found in undercooked meat like pork or bear

1) FEVER, VOMITING, PERIORBITAL EDEMA (large red glasses he’s wearing) and can see other symptoms on him as well

DOC:

1) ALBENDAZOLE 

or

2) MEBENDAZOLE

3) add CORTICOSTEROIDS for severe infeciton 

C) WUCHERERIA BANCROFTI = “witch” à kinda sounds like witchcraft (what’s more of witchcraft than turning someone into an elephant?)

1) ELEPHANTIASIS à longstanding lymphedema

DOC: 

1) DIETHYLCARBAMAZINE

E) LOA LOA: creepy blue worm guy

à transmitted by DEER FLIES (why flies are around him)

à migrates through the subcutaneous tissue of its host, and causes transient angioedema called CALLABAR SWELLINGS (shown by the swellings on blue guy)

à ADULT WORMS can MIGRATE ACROSS CONJUNCTIVA

DOC:

1) DIETHYLCARBAMAZINE

D) STRONGYLOIDES STERCORALIS = STRONG GUY

1) LARVAE PENETRATE SKIN OF SOLES OF FEET (red boots KICKING INTO WALL) 

DOC: 

1) IVERMECTIN 

-no sketchy for it 

1) BITHIONOL

TREMATODES (whale park scene) 

1) SHISTOSOMA  à SWIMMERS AT RISK OF INFECTION (why man is swimming)

                  à mature’s in the LIVER, and then is excreted in in feces

2) SNAILS = INTERMEDIATE HOST (why snails stuck to glass)

DOC: PRAZIQUANTEL

CLONORCHIS SINENSIS = chinese liver fluke = “orcha whale… ClonORCHis”

1) SNAILS = INTERMEDIATE HOST

Clonorchis sometimes transmitted from the snails à fish, and we sometimes eat the fish uncooked à SUSHI!!!

à cysta larva will then go inside us and reside in the BILLIARY SYSTEM, eventually causing biliary tract fibrosis, pigmented gallstones and even cholangio carcinoma

DOC: 

1) PRAZIQUANTEL

PARAGONIMUS WESTERMANI à sounds kind of like penguins

à penguins mostly black, but have 2 large white lung spots on chest with bl. on them

à b/c has potential to cause CHRONIC COUGH with BLOOD SPUTUM

INTERMEDIATE HOST = SNAIL

TRANSMISSION à via raw/undercooked crab meat that carry the encysted larvae

DOC: 

1) PRAZIQUNATEL

3) ECHINOCOCCUS GRANULOSUS (cockerspaniel dog…. Echinococcus)

-dogs are definitive host (why cockerspaniel is #1)

-sheep are intermediate host (why sheep dog is #2)

TRANSMISSION à via dog feces (why dog feces behind the winner)

1) HYDATID LIVER CYSTS à look like “EGG SHELL CALCIFICATIONS on CT)

à why there’s a trophy for the winning dog with a giant egg in it

à also why there’s a ribbon on the “liver spot” on the cockerspaniel

-LIVER CYSTS CAN RUPTURE --> cause anaphylactic reaction

DOC: ALBENDAZOLE

DOC:

1) PRAZIQUANTEL

2) NICLOSAMIDE 

1) ALBENDAZOLE OR

2) PRAZIQUANTEL

DOC: 

1) PRAZIQUANTEL

2) NICLOSAMIDE

DIPHYLLOBOTHRIUM LATUM = FISH TAPEWORM (guy running toward bathroom)

à bathroom sounds like bothrium, and who gets fish at a carnival…. Wtf?

à bathroom is beside a stand that says “MUST B12 to buy FIREWORKS (b/c fishworm stays in SI and inhibits absorption of VitB12 = COBALAMIN (cobalt blue firework)

à fireworks are bursting up in the sky and look like bursting RBCs à can remind us that it causes MEGALOBLASTIC ANEMIA

METRONIDAZOLE

1) MELARSOPROL

2) SURAMIN

prince charming etc

1) MELARSOPROL TREATMENT à used if it is a CNS INFECTION (can remember via the bar of soap prince bruce has)

2) SURAMIN TREATMENT à for a PERIPHERAL BLOOD INFECTION (life saving “SERUM” bottle for suramin)

DOC: 

1) PENTAMIDINE

1) PYRIMETHAMINE AND

2) CLINDAMYCIN

or

2) SULFADIAZINE

or

2) FOLONIC ACID 

BACKYARD OF CRAZY CAT LADY

1) PREGNANT WOMEN AT RISK OF TRANSPLACENTAL TRANSFER (pregnant lady bending down taking a picture)

2) TRANSMISSION à VIA 3 WAYS

1) OOCYTES CAT FECES à why she’s near the litter box picking up poop, and why there’s a bird egg in the litter box to remind us it’s OOCYTES

2) via RAW/POORLY COOKED MEAT that contains toxic tissue CYSTS (the meat bowl that immunocompromised cat is kicking over… since ghandi doesn’t like to eat)

3) VEGETABLES CONTAMINED BY OOCYTES FROM FECES

3) VERTICAL TRANSMISSION à ToRCHeS INFECTION à Toxoplasma part = this!!! (why there’s a statue of liberty cat holding a torch)

TREATMENT:

1) SULFADIAZINE à shown the the “dyed” sulphur eggs

2) PYRIMETHAMINE à shown by the pyramids on the eggs, and they are “smoking” to remind us of the meth

DOC:

1) SODIUM STIBOGLUCONATE OR

2) AMPHOTERACIN B 

LEISHMANIASIS à “DESERT MANIA” à featuring L. donovani, and L. baziliensis

HUMANS = HOST

FLY’S = VECTOR = SANDFLY VECTOR = PHEBLOTOMINE SAND FLY (why the brazil guy has sand flies all around him) à is a WHITE SOCKED SANDLFY

TREATMENT:

1) STIBOGLUCONATE à used for CUTANEOUS LEISHMANIASIS (can remember stivo as t-bo à t bone steak on the ground)

2) AMPHOTERACIN B à used for VISCERAL LEISHMANIASIS (can remember via the frogs)

DOC:

1) TRIMETHOPRIM-SULFAMETHOXAZOLE = COTRIMOXAZOLE 

ping pong match;