Pharm Exam 9

What Mosquitos carry malaria

Female mosquitos

What are the two stages of parasite development

Primary: developmental

Erythrocytic: enter blood and infest erythrocytes

What malaria parasites have only one cell cycle of liver cell invasion

P. falciparum, P. knowlesi, P.malariae

What stage of malaria causes recurrent infections

dormant hepatic stage of P.ovale and P.vivax

Symptoms of Malaria

chills, fever, sweating and GI issues occur after the bite, check CDC yellow book for information about malaria endemics

What are tissue schizonticide

eliminates dormant or developmental liver forms (pyrimethamine and primaquine)

What are blood schizonticides

eliminates blood parasites (chloroquine, quinine, mefloquine, and pyrimethamine, sulphonamides, and sulphone)

What are gametocides

kill sexual stages and prevent transmission to mosquitos (quinone, chloroquine, mefloquine, primaquine)

What is sporogony

reproduction of spores

What is a radical cure

eliminates both hepatic and erythrocytic stages, None of these exist

Contraindications of chloroquine

changes in visual field (causes vision loss), porphyria and psoriasis

Quinine MOA

interferes with the ability of the pathogen to dissolve and metabolize hemoglobin (blood schizonticide)

What is quinine made out of

bark of the cinchona tree

Quinine Indications

Falciparum malaria (NOT used for prophylaxis)

What is quinine toxicity known as

Cinchonism and includes GI distress, headache, vertigo, blurred vision, and tinnitus, can cause hemolysis in G6PD deficiency

What is blackwater fever

hemolysis and hemoglobinuria due to hypersensitivity reaction to quinone

Quinone interactions

Coumadin: prolongs prothrombin time

Digoxin: increases levels

Do not administer concomitantly with mefloquine due to increase risk of cardiac arrest and seizures

Mefloquine (lariam) contraindications

pts with a history of psychiatric disease or seizures

other quinone-like drugs can cause prolonged QT interval and seizures

Mefloquine black box warning

vomiting, hallucinations, tinnitus, dizziness, loss of balance

What class of drug is Primaquine

tissue schizonticide and gametocide

What is primaquine used for

Used to eradicate the liver stage of P.ovale and P.vivax

Primaquine MOA

interferes with electron transport chain in the parasite

Primaquine contraindications

G6PD deficiency and pregnancy

Primaquine adverse effects

hemolytic anemia, cardiac arrhythmias, MOST commonly causes an acute hemolytic reaction in G6PD deficient patients

What is the oral long acting analog of primaquine

Tafenoquine

Tafenoquine indications

prophylaxis in adults and hepatic stages in patients older than 16

Adverse effects of tafenoquine

hemolytic anemia

Tafenoquine contraindications

G6PD deficiency, history of psychosis, pregnancy and breastfeeding

Atovaquone MOA

disrupts mitochondrial electron transport in plasmodia (blood schizonticidal)

What is atovaquone combined with

Proguanil to become malarone

What is used as treatment and chemoprophylaxis of Falciparum malaria

atovaquone

What are the antifolate drugs

Pyrimethamine and proguanil (inhibit dihydrofolate reductase) and sulfadoxine (inhibits dihydropteroate synthase)

Pyrimethamine MOA

inhibits parasitic dihydrofolate reductase

blood schizoticidal and some tissue activity

arrests sporogony

Pyrimethamine Indications

acts slowly against erythrocytic forms of susceptible strains of all five human malaria species.

Is pyrimethamine DOC?

No because it has severe adverse reactions

What is Fansidar

combination of pyrimethamine and sulfadoxine

Fansidar MOA and indication

sequential blockade of folate synthesis

used in intermittent preventative therapy in pregnant women and young children

Contraindications of Fansidar

hypersensitivity to drug or sulfa allergy

What drug can cause SJS and toxic epidermal necrolysis

fansidar

Doxycycline MOA

active against erythrocytic schizonts of all human malaria parasites, not active against the liver stages

What is doxycycline commonly used in combo with

quinine or quinidine for falciparum malaria

Clindamycin MOA

binds at 50s ribosomal unit

Clindamycin indication

effective against P.falciparum even as monotherapy but is slowly acting. Not recommended in cases where fast parasite clearance is necessary

What drug was used in China for over 2000 years for fever

Artemisinins

Artemisinins MOA

production of free radicals or inhibition of parasite calcium ATPase

Leishmaniasis is caused by

the bite of sandflies infected with protozoan parasites

Affects some of the world’s poorest populations and is associated with poor nutrition

Leishmaniasis symptoms

fever, weight loss, swelling of the spleen and liver

Giardiasis causes and MOA

diarrhea; lives in the intestines and is passed in stool, contracted by contaminated food and water or person-person

What is the most common STD

trichomoniasis, causes symptoms in women

What is cryptosporidiosis and where does it come from

Infection by protozoan causing diarrhea, comes from food and water tainted with stool, can occur with swimming

Emetines MOA

inhibit protein synthesis by blocking ribosome movement along messenger RNA

Emetine indication

unusual circumstances of severe amebiasis in which metronidazole cannot be used

Paramomycin MOA

aminoglycoside antibiotic inhibits protein synthesis

Indications and contraindication of Paromomycin

Indication: intestinal amebiasis

Contra: renal insufficiency

Nitazoxanide indications

giardia lamblia, DOC for cryptosporidium

Nitazoxanide adverse effects

Bright yellow urine, abdominal pain, yellow sclera

Pentamidine indication

MOA is unknown

Treats pneumonia caused by P. Jirovecii in patients who fail to respond to TMP-SMX

Tx of african trypanosomiasis

Tx of visceral leishmaniasis

Metronidazole is the DOC for

severe amebic disease for hepatic abscess

What is metronidazole indicated for

trichomoniasis, amebiasis, and anaerobic bacterial infection (causes metallic aftertaste and disulfiram reaction)

Pyrimethamine/Sulfadiazine is the DOC in

toxoplasmosis

alternative to TMP/SMX or pentamidine for prophylaxis against pneumocystis pneumonia in AIDs pts

Elfornithine MOA

inhibits ornithine decarboxylase

What is the first line therapy for West African Trypanosomiasis

elfornithine

Adverse effects of Eflonithine

thrombocytopenia, leukopenia, seizures

Nifurtimox is used for

American trypanosomiasis (chagas)

Nifurtimox MOA

interacts with parasitic nucleic acid, inhibits trypanothione reductase

Liposomal Amphotericin B MOA

binds to parasite cell membrane, causing pores and ion leakage and ultimately cell death

DOC for visceral leishmaniasis

Liposomal Amphotericin B

TOC for amebiasis, giardiasis, trichomonas

metronidazole-symptomatic invasive disease

paromomycin-noninvasive disease

TOC for african trypanosomiasis

fexinidazole and nifurtimox-eflornithine

Classes of antihelminths

Benzimidazoles, macrolytic lactones, piperazine, praziquantel

Albendazole MOA

inhibits microtubule synthesis in nematodes

Adverse effects of Albendazole

when used for 2-3 days: none

Long term: liver toxicity, agranulocytosis, pancytopenia

Diethylcarbamazine citrate MOA

immobilizes microfilariae and alters their surface structure displacing them from tissues and making them more susceptible to destruction by host defenses

Diethylcarbamazine citrate is the DOC for

filariasis, loiasis, and tropical eosinophilia

Ivermectin is the DOC in

strogyloidiasis (threadworms) and onchocerciasis (river blindness) and an alternative treatment for filariasis

Ivermectin intensifies

GABA-mediated neurotransmission in nematodes and causes immobilization

Why does selective toxicity happen with Ivermectin

GABA is a neurotransmitter in the CNS and ivermectin cannot cross the blood brain barrier

Mebendazole MOA

inhibits microtubule synthesis in nematodes, thereby irreversibly inhibiting glucose uptake

What is the DOC in roundworms

mebendazole (minimal toxicity to humans)

Piperazine MOA

causes paralysis of ascaris by blocking acetylcholine at the myoneural junction

What is piperazine used in

Ascariasis and pinworms

Contraindicated in pregnancy or renal failure

Praziquantel MOA

increases the cell permeability to calcium causing paralysis of worm and detachment

What is praziquantel used in

schistosomiasis, cysticercosis, intestinal trematodes and TAPEWORMS

Pyrantel Pamoate MOA

stimulates nicotinic receptors present at neuromuscular junctions of worms by causing release of acetylcholine

Pyrantel pamoate is DOC for

hookworms (broad spectrum anthelmintic for pinworms as well) available OTC

Pyrantel pamoate contraindications and interactions

Contra: pregnancy and liver disease

Interactions: piperazine antagonizes the effects

Triclabendazole MOA

tegumental disruption by inhibition of microtubule based processes or adenylate cyclase activity

Triclabendazole indications

treat fascioliasis (infection caused by liver fluke parasite)

Miltefosine MOA

inhibition of mitochondrial cytochrome C oxidase

Miltedosine indications

Cutaneous Leishmaniasis

Miltefosine Side effects

abdominal pain, bloating or swelling of face/arms/hands/lower legs/feet, bloody/black/tarry stools, chills and fever