deck_5751816 Flashcards
Acyclovir works by being phosphorylated by viral TK, after it enters the human host cell. Once phosphorylated it undergoes two more phosphorylations by host DNA.
Acyclovir works by being phosphorylated by viral ___ after it enters the human host cell. Once phosphorylated it undergoes two more phosphorylations by but now by host DNA.
How do you get resistance to Acyclovir?
By mutated viral TKs
What drug do you get after esterifying acyclovir? What is the advantage?
Famciclovir and Valciclovir. These prodrugs are more bioavailable.
What drug offers additional CMV coverage in addition to HSV and VZV?
Gancliclovir
T/F: If a person is resistant to acyclovir, they will also be resistance to ganciclovir
True. They both need to be phosphorylated by viral TK. If viral TK is mutated, both drugs won’t work.
What is an adverse side effect of ganciclo and valganciclo?
Myeolosupression.
_____ works on directly by inhibiting viral DNA polymerase. If you have a acyclovir/ganciclovir resistant HSV infection, what should you use?
Foscarnet works on directly on viral DNA polymerase. Use Foscarnet.
You must treat influenza with drugs within how many hours?
48 hours
Rimantadine and amantidine are active against ___
influenza A only.
What are the NA inhibitors? What strains do they work on?
Oseltamavir and ZanamivirThey work on both A and B.
When treating hepatitis C, you should use what two drugs?
INF-alpha and Ribavirin
List the topical antifungals:
Azoles (Myconazole, Ketoconazole and Terbinafine)
Your patient has a tinea cruris and tinea pedis. What do you give?
Terbinafine, Ketoconazole or Myconazole.
For candida vaginitis, you can use a topical azole or oral ___
fluconazole
___ is a broad spectrum anti-fungal. It treats all yeast and molds. It even gets into fat.It works by intercalating with ergosterol on fungal cell membrane, decreasing membrane _____
Amphotericin is a broad spectrum anti-fungal. It treats all yeast and molds. It even gets into fat.It works by intercalating with ergosterol on fungal cell membrane, decreasing membrane permeability.
Ampho (lipid form) and ampho IV form both do the same thing, but one of them is less toxic and more efficient. Which one?
Ampho lipo form
How does fluconazole work?
It inhibits synthesis of ergosterol by inhibiting the P450 system.
___ gets across the BBB, is very bioaviable and works against yeast EXCEPT for ___ and ____
Fluconazole gets across the BBB, is very bioavailable and works against yeast except for C. krusi and C. glabrata.
___ is important when treating cryptococcus infections, and candida infections that get into the blood stream
Fluconazole
Ampho + ___ is great to treat a candida infection for the first two weeks. After two weeks, you should switch to ____
Ampho + Flucytosine is great to treat a candida infection for the first two weeks. After two weeks, you should switch to Fluconazole.
___ is an antifundal that is a nucleic acid synthesis inhibitor.
Flucytosine
Flucytosine works synergistically with ____
Ampho B
___ is an azole that adds activity against molds and dimorphic fungi. It is not, however, as good as voriconazole.
Itraconazole
Posacanazole and isocanazole is a very broad spectrum antifungal and can be used against bread mold infections such as __ and ___
rhizopus and mucomycosis
The echinocandins are active against yeast, but will not cover ___. How is it administered?
cryptococcus. It is administered via IV.
If you have a resistant candida infection like C. Glabrata and C. Krusei, what two drugs could you use?
Casperfungin or Ampho. Use Casperfungin because it is less toxic.
For the tapeworm and cystercercosis, humans can be both the __ and __ host.
intermediate and definitive
Which two protoza are found in water?
Cryptosporidium and Giardia
What drug should you use against Giardia?
Metro
What is the life cycle of the protozoas?
Cyst, Trophozoid, Cyst, Trophozoid, etc.
___ is a very invasive protoza and can cause bloody diarrhea and fever.
Amoeba
___ attached to the small intestine wall and causes mal-absorption, but does not enter the mucosal cells.
Giardia
___ is an intracellular pathogen that causes cell dysfunction by entering the cell, but it is not invasive.
Cryptosporidium
Do you get eosionophilia with protoza gut infections?
No. Two things are needed for your infection to become eosinophilic. First, you need a complex organism (like a worm), and then you need tissue invasion.
Do amoeba infections cause eosinophilia?
No. It is unicellular. Malaria is not unicellular but it does not cause tissue invasion, so it does not cause eosinophilia.
How does one get hookworm? What is the life cycle?
How does one get hookworm? Take your shoes off, get in contact with fecally contaminated areas where hookworm eggs exist. The egg gets into soil, hatches, and gets into you by penetration of skin (in filariform form - third stage larvae), often through skin. It can enter the post capillary venules, work its way into the lung, where it get into capillaries of lung, burrow through into the alveolus of the lung, up the airway it goes, into the back of throat. You then swallow it, and the hookworm sets up shop in your intestines. At that point of attachment, you get RBC leakage. If you get enough RBC leakage, you’ll get iron deficient anemia. So if you want to interupt transmission of hookworm, you need to have good sanitation and put shoes on.
__ __ __ is the dog or cat hookworm that tries to penetrate your skin, but cannot penetrate. You get a snake-looking thing under your skin
Cutaneous larvae migrans
Schistomiases is transmitted via fresh ___. The intermediate host is the ___, the definitive host is the ___. If you get infected with S. Manosium or Japonicum, the cycle takes place in the ___ __ _system. If you get infected with S. hematobium, it will complete its cycle in your ____. If it gets stuck in your vein, it will cause ___ or scarring. It can also cause liver cirrhosis in the case of S. ___ and bladder cancer from S. ____.If the egg gets into environment and finds its way into water, the egg hatches and forms an intermediate life form that infects the ___. The ___ releases cercariae which then penetrate your skin. You have to be in ___ for schisto to infect you.
Schistomiasis is transmitted via fresh water. The intermediate host is the snail, the definitive host is the human. If you get infected with S. Manosium or Japonicum, the cycle takes place in the venous portal circulation system. If you get infected with S. hematobium, it will complete its cycle in your bladder. If it gets stuck in your vein, it will cause fibrosis or scarring. It can also cause liver cirrhosis in the case of S. Manosum/Japonicum and bladder cancer from S. Hematobium.If the egg gets into environment and finds its way into water, the egg hatches and forms an intermediate life form that infects the snail. The snail releases cercariae which then penetrate your skin. You have to be in water for schisto to infect you.
If a tapeworm is in our intestines, we are the ___ host. After the ____ attaches to our intestinal wall, they grow and grow. How do we get tapeworm into our intestines? By eating meat that is infected with cistercercosis. When the larvae hatches, the ___ attaches to our intestinal wall, and ___ are made. You end up with very long tapeworms. Segments then leak out and get into the environment. If they get into the muscles, it is not a problem. But if it gets into the brain, it can cause seizures – central american encelphalopathy.
If a tapeworm is in our intestines, we are the definitive host. After the tapeworm attaches to our intestinal wall, they grow and grow. How do we get tapeworm into our intestines? By eating meat that is infected with cistercercosis. When the larvae hatches, the scolex attaches to our intestinal wall, and proglottids are made. You end up with very long tapeworms. Segments then leak out and get into the environment. If they get into the muscles, it is not a problem. But if it gets into the brain, it can cause seizures – central american encelphalopathy
When you put a patient on TB medication, you want to put them on ___ drugs for __ months. After __ months, you should put them on how many drugs?
When you put a patient on TB medication, you want to put them on four drugs for two months. After two months, you should put them on 4 drugs
INH and RIF are corner stone drugs that can all cause ____ as a side effect
hepatitis
Two important side effects of INH are: __ and __. What vitamin should you give along with INH?
INH:Peripheral neuropahy and hepatitis. You should give B6 at the same time.
T. Brucei is transmitted by the ____ ____ and can cause __ sickness and ___.
T. Brucei is transmitted by the Tsetse fly and can cause sleeping sickness and encelphalitis
T. Cruzi is transmitted by the ____ bug and causes ___ disease which is __ ___ disease.
T. Cruzi is transmitted by the Reduvid bug and causes Chaga’s disease which is mega organ disease.
Babesia micron infections are caused by the ___ tick. Symptoms are very similar to ___, however, these infections are usually contracted from __ area.
IxodesMalariaNew England (Martha’s Vineyard)
Tularemia and Babesia are both common in the ___ area
New England
What is the Malaria Life Cycle?The ___ gets injected into the human by the mosquito. The ___ then goes to the ___. In the ___, a ___ is formed from infection of the hepatocyte. This ___ has two options:1. Fully mature and produce ___ which rupture and then affect RBC’s (note this occurs with all four species of malaria)2. Go dormant and go to sleep. It is now called a ____. We see this in ___ and ___.The most virulent and dangerous of all four is the ____. Once the hepatic ___ ruptures and merozites leave, they mature into ___. ___ can do two things:1. They can rupture RBC’s and infect other RBCs2. They can form ___ which are picked up by a mosquito. The ___ mate in the mosquito. __ then form, and inhabit the salivary glands of the mosquito.
What is the Malaria Life Cycle?The sporozoite gets injected into the human by the mosquito. The sporozoite then goes to the liver. In the liver, a schizont is formed from infection of the hepatocyte. This schizont has two options:1. Fully mature and produce merozoites which rupture and then affect RBC’s (note this occurs with all four species of malaria)2. Go dormant and go to sleep. It is now called a hypnozoite. We see this in P. Ovale and P. VivexThe most virulent and dangerous of all four is the P. FarciparumOnce the hepatic schizont ruptures and merozites leave, they mature into trophozoites. The trophozoite can now do two things:1. They can rupture RBC’s and infect other RBCs2. They can form gametocytes which are picked up by a mosquito. The gametes mate in the mosquito. Sporozites then form, and inhabit the salivary glands of the mosquito.
Several drugs work against erythocytic stage. What are they?
Quinine, Quinidine, Doxycicline, Chloroquine (inhibits heme polymerase), Mefloquine,.
Tovoquone/Proguanil is another anti-malarial drug that works on the the __ stage and __ stage
Hepatocytic schizontErythocytic stages
What do you use as terminal prophylaxis?
Pimaquin
____/____ (IV form) is used for treating P. Falciparum for people who actually have the active disease.
Quinine/Quinidine
The drug that reduces parasitemia the quickets is _____
ART
Cycle of Antibiotic Resistance Acquisition:Bacterial SelectionUnder increasing antibiotic selection pressure:1. Bacteria resistant to a particular drug are ___ and ____2. Different antibiotics select different bacteria but can select ____ phenotypes to other drugs as well3. This results in ____ organisms and increases their total number
Under increasing antibiotic selection pressure:Bacteria resistant to a particular drug are selected and replicateDifferent antibiotics select different bacteria but can select resistant phenotypes to other drugs as wellThis results in multidrug-resistant (MDR) organisms and increases their total number
