When two or more medicines
are taken together, it can change how the medicines work and increase the risk of side-effects. In medical terms, this is called as a Drug Interaction
Sulfamethoxazole/Trimethoprim interacts with phenytoin
, which is used for the treatment of seizures
is known to prevent the breakdown of phenytoin in the liver
. When Co-Trimoxazole
is given at a recommended dose, the blood levels of phenytoin were found to increase, and the clearance was decreased. When Co-Trimoxazole is given in combination with phenytoin, the possible effects of phenytoin should be known.
Special instructions need to be followed while taking this medicine along with methotrexate
, which is used to treat cancer
and as an immunosuppressant. Sulfonamides
such as Co-Trimoxazole
can replace methotrexate from its protein
binding sites in the blood and also competes with the transport of methotrexate in kidneys, which can result in increased levels of free methotrexate. cyclosporine
, which is used to prevent organ rejection during transplantation procedure.
Your doctor's guidelines may need to be followed while taking this medicine along with When Co-Trimoxazole
is used along with cyclosporin
, the patients who have undergone kidney transplant may experience reversible kidney damage. The levels of digoxin
in the blood may get increased when given in combination with Co-Trimoxazole
, particularly in elderly patients. The levels of digoxin
in blood should be monitored.
There may be an interaction of Co-Trimoxazole
, which is used to treat parasitic infections. The patients who receive pyrimethamine
to prevent malaria
at a dose exceeding 25 mg a week may develop unusually large, structurally abnormal, and immature red blood cells (megaloblastic anemia
) if Co-Trimoxazole
Sulfamethoxazole/Trimethoprim interacts with tricyclic antidepressants
, which is used for the treatment of depression
. The effectiveness of tricyclic antidepressants decreases when given with Co-Trimoxazole
Special instructions need to be followed while taking this medicine along with oral hypoglycemics
, which are used to lower high blood glucose
levels. Like other drugs that contain sulfonamide, Co-Trimoxazole
also enhances the effect of oral hypoglycemics.
Your doctor's guidelines may need to be followed while taking this medicine along with amantadine
, which is used for the treatment of viral infections and Parkinson's disease. When Co-Trimoxazole
was given in combination with amantadine, a single case of delirium
which is characterized by restlessness, illusions, and incoherence (delirium) has been reported in the literature.
may interact with angiotensin-converting enzyme
inhibitor, which is used for the treatment of high blood pressure and heart failure. When Co-Trimoxazole
was used in combination with angiotensin-converting enzyme
inhibitor, three cases of high levels of potassium
in the blood in elderly patients have been reported in the literature.
Sulfamethoxazole/Trimethoprim interacts with zidovudine
, which is used to prevent and treat HIV/AIDS. Use of Co-Trimoxazole
with zidovudine increases the risk of blood-related side effects and when Co-Trimoxazole
is used in combination with lamivudine increases the exposure of lamivudine because of the trimethoprim component
of Co-Trimoxazole. If the treatment with these drugs is important, monitoring of blood parameters should be done.
Special instructions need to be followed while taking this medicine along with procainamide
, which is used to treat irregular heart rhythm. When trimethoprim
is taken along with drugs that form cations at physiological pH, and are partly excreted by kidneys (e.g., procainamide, amantadine
), there is the possibility of prevention
of this process which may increase the levels of one or both the drugs.
Your doctor's guidelines may need to be followed while taking this medicine along with folinic acid, which is used to decrease the harmful effects of methotrexate
. Supplementation with folinic acid has been shown to interfere
with the antimicrobial effectiveness of Co-Trimoxazole
This page does not contain all the possible interactions of Sulfamethoxazole/Trimethoprim. Share a list of all medicines that you use with your doctor and pharmacist. Do not start, stop, or change the dose of any medicines
without the approval of your doctor.