Term
|
Definition
| Toxoplasmosis gondii : 1. Single-cell obligate, intracellular protozoan parasite 2. Oocyst (dormant form) and tachyzoites (active form)3. Cats primary host 4.Transmission by ingestion of under-cooked meat and transplacental (severity related to stage of pregnancy) 5.Frequent reactivity common in HIV patients |
|
|
Term
| Reactive Toxoplasmosis Signs |
|
Definition
| 1. Creamy, white, focal chorioretinal lesions 2. Vitritis and iridocyclitis protozoan parasite 3. Recurrent lesions tend to occur at the border of old chorioretinal lesions |
|
|
Term
| Active Agents against Reactive Toxoplasmosis |
|
Definition
| Pyrimethamine and trimethoprim, Sulfonamides (Sulfadiazine, Sulfamethoxazole, Sulfacetamide |
|
|
Term
| Pyrimethamine and trimethoprim |
|
Definition
| A. Mechanism of action – interferes with intermediary metabolism of folic acid by binding and blocking the activity of dihydrofolic reductase: Pyrimethamine (DOC) especially active at this site and produces a synergistic action nin used in combination with sulfas (e. g. sulfadiazine) |
|
|
Term
| Pyrimethamine and Triemethoprim Kinetics and Resistance |
|
Definition
| Oral only systemically, Good GI absorption, Approximately 35% in free form, Good distribution, Urinary excretion; RESISTANCE: Bacteria using folic acid from exogenous source due to lack of enzyme for synthesis, Altered composition of the enzyme, Altered cell membrane permeability |
|
|
Term
| Pyrimethamine , trimethoprim and Polytrim |
|
Definition
| (treatment for reactive toxoplasmosis) Pyrimethamine – 75 mg loading dose, then 25 mg qd for 7-10 days (in combination with sulfadiazine 250 mg qid) Trimethoprim – 80 - 160 mg daily in combo with 400-800 mg daily of sulfamethoxazole (septra, bactrim; 80/400, 160/800) *f. Polytrim oph sol. Particular active haemophilus influenza conjunctivitis - More common in children with upper respiratory infections |
|
|
Term
| Pyrimethamine and trimethoprim Adverse Effects |
|
Definition
| Hematological disturbances, Hypersensitivity (skin ras, urticaria, SJS), Gastrointestinal disturbances |
|
|
Term
| Mechanism of Action for Sulfonamides |
|
Definition
| mechanism of action interes with intermediary metabolism of folic acid by binding and blocking the activity of pteridine synthase by competing with PABA for the enzyme’s binding site. |
|
|
Term
|
Definition
| Oral only systemically, Short to long actig (1/2 life), Absorption in the stomach and small intestine, good tissue distribution (CSF), Wide range of protein bound, Urinary excretion |
|
|
Term
| Drug of Choice for the treatment of active ocular toxoplasmosis |
|
Definition
| Sulfadizine in combination with pyrimethamine; (250 mg qid in combination with pyrimethamine for 7-10 days |
|
|
Term
|
Definition
| Bacteria that lack enzyme for folic acid synthesis rely on exogenous source for purine production Bacteria mutation causing an excess of PABA which decreases the affinity of sulfonamides for pteridine synthase; |
|
|
Term
|
Definition
| Second line treatment in combination with trimethoprim for the treatment of active ocular toxoplasmosis; Third line treatment of choice for chlamydia infections |
|
|
Term
|
Definition
| 10% ophthalmic solution of the treatment of non-purlanet bacterial conjunctivitis |
|
|
Term
| Sulfonamides Adverse Effects |
|
Definition
| Hypersensitivity (skin rash, urticaria, SJS, photosensitivity) Cross alltergenciity sulfonylurea, diuretics (carbonic, anhydrase inhibitors, loop diuretics, thiazides, celbrex); Gastrointestinal disturbances, |
|
|
Term
|
Definition
| 1. Relatively uncommon 2. Related to intraocular surgery (poor aseptic/ sterile technique) 3. Staph. Aureus and epidermidis most common 4. Signs and symptoms (sudden VAL, Pain, severe episcleral and conjunctival inflammation, severe anterior and posterior segment intraocular inflammation, Hypopyon) |
|
|
Term
| Treatment for Bacterail Endothalmitis |
|
Definition
| Vancomycin, Amikacin (Aminoglycoside) |
|
|
Term
|
Definition
| Ttmt. for Bacterial Endothalmitis; Inhibit bacterial cell wall synthesis, Active against staph, strep, clostridium and neisseriae, In ocular surface infection only reserved for severe cases in which less toxic agent that have been ineffective,Great activity against MRSA and MRSE, DOC for staph endophathlmitis 0.25% intravitreal concentration, Prolonged oral used may cause ototoxicity and nephrotoxic, high allergic potential, contraindicated in patients with known hypersensitivity to the drug, also in cases of hearing loss and severe renal impairment |
|
|
Term
|
Definition
| Aminoglycocoside; Very active against gram negative bacilli, Chemical modification present makes it tolerant to many aminoglycoside inactiviating enzyme e chemical , In ocular surface infections only reserved for severe cases in nwhich less gentamicin and tobramycin have been ineffective, Primary agent along with vancomycin for the treatment of bacterial endophthalmitis, Ototoxicity, nephrotoxicity, and neuromuscular blockage contraindicated in patients with of hearing loss, severe renal impairment and neuro muscular disease. |
|
|
Term
| Bacterial Optic Nneuropathies (neuroretinitis) |
|
Definition
| Bacterial neuroretinal inflammation seen more frequently in young patients. Signs and symptoms: painless VAL, usually unilateral, Disc edema with peripallary hemorrhages, Vitritis, “Macular Star” |
|
|
Term
| Lyme Disease Bacterial Optic Neuropathies |
|
Definition
| Borrelia burgdorferi (spirochete, tick bite) Oral or IV PCN, doxycycline, erythromycin, ceftriaxone, |
|
|
Term
|
Definition
| Toxoplasmosis gondii, Pyrimethamine, Trimetroprim, Sulfadiazine, Sulfamethoxaole, Tetracycline, Clyndamicin |
|
|
Term
| Cat Scratch fever Bacterial Optic neuropathitis |
|
Definition
| Bartonella henselae or Quintana |
|
|
