Trimethoprim

Generic name: Trimethoprim

Drug class: Urinary anti-infectives

Dosage forms: Tablet

Root of administration: Oral

Dose: 100 mg

Mechanism of action: It exerts its antimicrobial effect by targeting and inhibiting the enzyme dihydrofolate reductase (DHFR), which is involved in the synthesis of tetrahydrofolate (THF), an essential precursor for the synthesis of nucleic acids (DNA and RNA) in bacteria.

Drug usage cases: Trimethoprim is an antibiotic that is used to treat bladder or kidney infections, or ear infections caused by certain bacteria.

Drug contra indications: You should not use trimethoprim if you are allergic to it, or if you have:

anemia (low red blood cells) caused by a folate (folic acid) deficiency. Trimethoprim is not approved for use by anyone younger than 2 months old. Trimethoprim should not be used to treat an ear infection in a child younger than 6 months old. Tell your doctor if you have ever had:

a folate deficiency; liver or kidney disease; or a blood disorder. Trimethoprim can interfere with your body’s ability to metabolize folic acid, a form of vitamin B important in the development of the unborn baby’s brain and spinal cord.

Side effects: Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat. Trimethoprim may cause serious side effects. Call your doctor at once if you have:

severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose); pale, gray, or bluish skin; fever, weakness; sore or swollen tongue; easy bruising, purple or red spots under your skin; a skin rash, no matter how mild; or high potassium level–nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement.

Warnings: You should not use trimethoprim if you have anemia caused by a folate (folic acid) deficiency.

Use during pregnancy or breastfeeding: Tell your doctor if you are pregnant. It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.