Pharmacology methotrexate

Where in the cell cycle does methotrexate act?
S-phase

What is the MOA for methotrexate?
Inhibition of DHFR resulting in depletion of THF & thymidine

What is the dosage range for methotrexate?
7.5mg/m2-35gm/m2

What are the three metabolic pathways of methotrexate?
1. DAMPA-intestinal bacteria
2. 7-OH MTX (primary metabolite-inactive)
3. Polyglutamates

Which of methotrexates metabolic pathways is the primary metabolite?
7-OH MTX (inactive)

Which of the three metabolic pathways of methotrexate allows for it to stay in the cell longer resulting in a better chemo response?
Polyglutamates

What is the primary excretion pathway of methotrexate?
Renal

Methotrexate is primarily excreted by the kidneys via what two ways?
1. Glomerular filtration
2. Tubular secretion & reabsorption

What are the two factors that can alter MTX clearance?
1. Hydration status-measure urine specific gravity
2. Urine pH-must be >6.5 or adjust with NaCO3

What are the top 5 MTX toxicities?
1. Bone marrow suppression-Pancytopenia
2. Mucositis
3. Nephrotoxicity-precipitation of MTX/7-OH in tubules
4. GI desquamation
5. Inadequate leucovorin rescue

What is time that you must start MTX leucovorin rescue by?
36-45 hours after dose

What is the typical [MTX] that you look for until consider at low risk for toxicity?
<0.1mM

What are MTX drug interactions?
Salicylates & Sulfonamides

What 4 things do you monitor to avoid MTX toxicities?
1. Adequate hydration & good urine output
2. Urine pH >6.5
3. Drain pleural effusions prior to MTX
4. Adjust leucovorin rescue based on [MTX]

What is half-life? The amount of time required for 50% of drug remaining in the body to be eliminated How are drugs usually eliminated? By chemically altering original compound while still in body, By excreting the active form of the …

Additive effects drug interactions in which the effect of a combination of two or more drugs with similar actions is equivalent to the sum of the individual effects of the same drugs given alone (1+1=2) compare with synergistic effects Adverse …

alopecia hair loss; a common adverse effect of many antineoplastic drugs, which are more effective against rapidly multiplying cells such as those of hair follicles anaplasia loss of organization and structure; property of cancer cells WE WILL WRITE A CUSTOM …

Heparin MOA Cofactor for activation of antithrombin. Decreases thrombin and factor Xa. Clinical use, heparin Immediate anticoagulation for PE, acute coronary syndrome, MI, DVT. Used during pregnancy (doesn’t cross placenta). Follow PTT. WE WILL WRITE A CUSTOM ESSAY SAMPLE ON …

What marked the beginning of modern pharmacology? During the 1800s chemists were able to isolate the pure chemicals from plants. When did mass production of medicine begin? In the World War II era (1939-1945) WE WILL WRITE A CUSTOM ESSAY …

Anethetists often administer midazolam (Versed) during induction of anesthesia because of which of the pharmacologic actions? causes amnesia adverse effects, carbamazepine (Tegretol)? a) begin taking the drug at a low dosage Adverse effects: visual distrubances, vertigo, and ataxia can result …

David from Healtheappointments:

Hi there, would you like to get such a paper? How about receiving a customized one? Check it out https://goo.gl/chNgQy