Drug Interaction:
Interacting drugs- summary
+ Methotexate
Aminoglycosides oral
methotrexate absorption and bioavailability decreased
Charcoal
charcoal lowers plasma levels of both oral and IV MTX and significant
with high dose therapies. This will reduce effectiveness and toxicity of MTX
Folic acid
folic acid or its derivatives contained in some vitamins can decrease
response of MTX
NSAIDs-
concurrent MTX admin. caused fatal interactions in 3 patients with keroprofen
1 with naproxen. Indomethicin and phenylbutazone increased MTX
plasma levels. Mechanism of action not known.
Administer concomittantly with extreme caution if at all.
Phenytoin
serum conc. decreased by combination chemotherapy regimen
including MTX.
Probenecid / Salicylates / Sulfonamides inclu TMP-SMZ
therapeutic and toxic effects of MTX may be increased by these agents
Procarbazine
increase the nephrotoxicity of MTX
Thiopurines
MTX increase AUC and plasma levels of thiopurines
Adverse Reaction:
Myleosuppression,renal failure. Ulcerative stomatitis, leucopenia, Hepatotoxicity, nausea, Abdominal distress, Malaise, fatigue, Chills, fever,
Dizziness, Decreased resistence to infections, Rash, Bone marrow depression, Gingivitis, Renal failure, Intestinal pneumonitis, headache, Blurred vision. Falsely high protein levels in CSF.
Patient Information:
1. Avoid alcohol, salicylates, and prolonged exposure to sunlight or sun lamps
2. May cause nausea, vomiting, loss of appetite ,hair loss, skin rash, boils or acne. Notify if these persists.
3. Use contraceptive measures during and atleast first 3 months(males), or 1 ovulatory
cycle(females) after cessation of therapy.
4. Notify physician if these occur: Diarrhoea, abdominal pain, black tarry stools, fever and chills, sore throat, unusual bleeding, or bruisding, sores in or around the mouth, cough or shortness of breath, yellow discolouration of the skin or eyes, darkened urine, swelling of the feet or legs ; joint pain.
5.Allergies- tell your doctor if you have ever had any unusual or allergic reaction to methotrexate
Also tell your doctor if you are allergic to any other substances, such as foods, presrvatives or dyes.
6.Pregnancy - there is a good chance that this medicine may cause birth defects f male or female is taking at the time of conception or taken during pregnancy.
7.Breast feeding- because methotrexate may cause serious side effects breat feeding is not recommended while you are taking it.
8 Children - not expected to cause different side effects in children with use in other age groups
10. Elderly- side effects more likely to occur in elderly.
11. Other medicines -
Let your doctor know what other medicines you are taking, so that he can advice you accordingly.
Non prescription or OTC medicines
If you have ever been treated with x-rays or cancer medicines or if you drink alcohol
12. Other medical problems -
Tell your doctor if you have any other medical problems especially -
Alcohol abuse - increased risk of unwanted side effects
Chickenpox or
Herpes zoster - risk of severe disease affecting the other parts of the body
Colitis or
Disease of the immune system or
Gout or
Kidney stones - methotrexate may increase levels of chemical cvalled uric acid innthe body which
can cause Kidney stones
Infection - methorexate can reduce immunity or infection
Intestinal blockage or
Kidney disease or
Liver disease - efects may be increased because of slower removal of methorexate from the body
Mouth sores or infalmmation or
Stomach ulcer- may be worsened
13. Missed dose -
If you miss a dose of this medicine, take it as soon as possible. however, if it is almost time for the next dose, skip the missed dose. Do not double doses.
14. Storage -
Keep out of reach of children. Store away from heat or direct sunlight. Do not store
the capsule in bathroom, near the kitchen sink, or in other damp places.
15. Outdated medicines -
Do not keep outdated medicine or medicine no longer needed. Be sure that any
discarded medicine is out of reach of children.
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