Patient with a macrocytic anemia
J.H. (38-year old female) comes to the oncology clinic. Two months ago, she underwent an uncomplicated surgical exploration due to an unknown ovarial tumor that was subsequently diagnosed as a choriocarcinoma of the ovary. Affected ovary was removed and doctor started methotrexate therapy. Till last weekend there were no complications. Now she presents with complaints of oral mucosal ulcers, higher tiredness and a feeling of tenderness in the stomach. On physical examination, patient was afebrile with no other signs of disease (only those mentioned above).
Blood count: platelets 60 000/ul, leukocytes 3 200/ul and signs of macrocytic anemia.
What laboratory values could lead the doctor to the diagnosis of macrocytic anemia?
How would you describe the values of platelets and leukocytes ? Do measured levels indicate any possible risk to our patient ?
Doctor measured a level of methotrexate in blood. Its value was within the recommended therapeutic range.
Do this finding rule out that methotrexate is a cause of this state ? Explain.
How could methotrexate induce above described health problems ?
Why were several organ systems affected ?
Cotrimoxazole (mixture of trimethoprim and sulfamethoxazole) is a frequently used chemotherapeutic drug that has a similar mechanism of action as methotrexate. But its effect is limited only to bacteria.
Describe the differences in the mechanism of action of methotrexate and cotrimoxazole. Are there any implications of these differences for their therapeutic use ?
If doctor decide to give folic acid to Mrs. J.H., will it change the action of methotrexate ? Would it be a desirable effect ?