Infections (Chronic and Acute) Flashcards
Type of parasite that causes malaria
Plasmodium
5 types of malaria
P. Falciparum, P vivax, P knowlesi, P. Malariae and P. Ovale
Most resistance malarial organism
Falciparum
Diagnosis of malaria
Thick and thin films- however if antimalarials have been taken then this can mask the result.
Uncomplicated vs complicated malaria features
Positive parasitology screen with Giemasa stain and thick and thin films. Severe malaria is defined as any of the following: parasite count higher than 2 % or 100, 000 per microlitre. Impaired consciousness Jaundice oliguria Resp distress Severe anaemia Hypoglycaemia Vomiting clinical acidosis AKI
In short- any end organ damage or signs of systemic illness.
Treatment of uncomplicated malaria
Artemether + lumefantrine 10/120mg first line
atovaquone + proguanil 250/100 mg second line
Quinine + doxy 600/100 mg third line
Which agent should be added in northern australia where human to host transmission is aiming to be limited
primaquine is given as a one off
Can not give to G6PD def. patients - severe haemolysis
Which malarial parasites can lie dormant in the liver
Ovale and vivax: Hypnozoites are not eliminated by the uncomplicated malaria regimen. Primaquine or tafenoquine should be given.
Treatment of severe malaria
Artesunate IV or if unavailable then IV quinine
Additional therapy in severe malaria
Addition of ceftriaxone and paracetamol is recommended- especially if hypotensive.
HIV treatments regimen
Typically made up of a nucleoside reverse transciptase inhibitor, Non-neucleoside transscriptase inhibitor and an integrase inhibitor
NRTI, NNRTI, Integrase inhib. Alternatively can have two NRTIs and an integrase
Entry inhibitors
maraviroc (binds to CCR5, preventing an interaction with gp41), enfuvirtide (binds to gp41, also known as a ‘fusion inhibitor’)
prevent HIV-1 from entering and infecting immune cells
Nucleoside analogue reverse transcriptase inhibitors (NRTI)
examples: zidovudine (AZT), abacavir, emtricitabine, didanosine, lamivudine, stavudine, zalcitabine, tenofovir
general NRTI side-effects: peripheral neuropathy
tenofovir: used in two recommended regime NRTI. Adverse effects include renal impairment and ostesoporosis
zidovudine: anaemia, myopathy, black nails
didanosine: pancreatitis
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
examples: nevirapine, efavirenz
side-effects: P450 enzyme interaction (nevirapine induces), rashes
Protease inhibitors (PI)
examples: indinavir, nelfinavir, ritonavir, saquinavir
side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition
indinavir: renal stones, asymptomatic hyperbilirubinaemia
ritonavir: a potent inhibitor of the P450 system
It acts by inhibiting aspartyl protease enzymes, preventing viral maturation and prevents functional virion formation.
Integrase inhibitors
block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell
examples: raltegravir, elvitegravir, dolutegravir
MOA azoles
Inhibits 14 alpha demethylase which produces ergosterol (adverse) = P450 inhibition and liver toxicity
Amphotericin B and nystatin MOA
Binds with ergosterol forming a transmembrane channel that leads to monovalent ion leak. Nephrotoxic
Terbinafine MOA
Inhibits squalene epoxidase
Griseofulvin MOA
Interacts with microtubules to disrupt mitotic spindle
Flucytosine MOA
Converted to 5-Flurouracil, inhibitis thymidylate synthase and disrupts protein synthesis
Caspofungin MOA
Inhibits synthesis of beta-glucan and major cell wall component
Name gram positive rods
Actinomyces Bacillus anthracis (anthrax) Clostridium Diphtheria: Corynebacterium diphtheriae Listeria monocytogenes
Gram positive cocci
Staph, Strep and enterococci
Gram negative coci
Neisseria and moraxella
Trimethoprim MOA
transient rise in creatinine: trimethoprim competitively inhibits the tubular secretion of creatinine resulting in a temporary increase which reverses upon stopping the drug
trimethoprim blocks the ENaC channel in the distal nephron, causing a hyperkalaemic distal RTA (type 4). It also inhibits creatinine secretion, often leading to an increase in creatinine by around 40 points (but not necessarily causing AKI)