Polymyxin B Sul-Trimethoprim (polymyxin B sulfate/trimethoprim)

Potency and dosage of polymyxin B sulfate are expressed in terms of polymyxin B activity (units of polymyxin B).

If trimethoprim is used for treatment of acute, uncomplicated urinary tract infections in adults with creatinine clearances of 15-30 mL/minute, dosage of the drug should be reduced to 50 mg every 12 hours. The drug is not recommended in patients with creatinine clearances less than 15 mL/minute.

For information on dosage of the fixed combination containing trimethoprim and sulfamethoxazole, see Co-trimoxazole 8:12.20.

Trimethoprim is administered orally. Trimethoprim also is administered orally or IV as a fixed-combination preparation with sulfamethoxazole. (For information on the fixed combination containing trimethoprim and sulfamethoxazole, see Co-trimoxazole 8:12.20.)

There is no enhanced messaging for this drug.

There are no contraindication interactions for this drug.

There are no severe interactions for this drug.

There are no moderate interactions for this drug.

There is no enhanced messaging for this drug.

There are no contraindication contraindications for this drug.

There are no severe contraindications for this drug.

• No disease contraindications

There is no enhanced messaging for this drug.

More Frequent

• Ocular inflammation
• Ocular itching
• Ocular redness

Less Frequent

• Ocular irritation

Rare or Very Rare

• Conjunctival hyperemia

No enhanced messaging available.

No enhanced messaging available.

Animal reproduction studies have not been performed with polymyxin B sulfate. It is not known whether ophthalmic preparations containing polymyxin B sulfate can cause fetal harm when administered to pregnant women.

Fixed-combination ophthalmic preparations of polymyxin B sulfate and bacitracin zinc or polymyxin B sulfate, neomycin sulfate, and either bacitracin zinc or gramicidin should be used during pregnancy only if clearly needed.

Because trimethoprim may interfere with folic acid metabolism, fixed-combination ophthalmic preparations containing polymyxin B sulfate and trimethoprim sulfate should be used during pregnancy only if potential benefits justify potential risks to the fetus.

Fixed-combination ophthalmic preparations containing polymyxin B sulfate, other anti-infectives (i.e., neomycin sulfate, bacitracin zinc), and a corticosteroid (i.e., dexamethasone, hydrocortisone, hydrocortisone acetate) should be used during pregnancy only if potential benefits justify potential risks to the fetus.

Fixed-combination otic preparations containing polymyxin B sulfate, neomycin sulfate, and hydrocortisone should be used during pregnancy only if potential benefits justify potential risks to the fetus.

Trimethoprim has been shown to be teratogenic in rats when given in doses 40 times the usual human dose; in rabbits, an overall increase in fetal loss was associated with trimethoprim doses 6 times the usual human dose. Although there are no adequate and controlled studies to date using trimethoprim in humans, a retrospective study that reported the outcome of 186 pregnancies suggested that the incidence of congenital abnormalities in those who received the fixed combination containing trimethoprim and sulfamethoxazole (co-trimoxazole) was similar to that in those who received a placebo. Because trimethoprim may interfere with folic acid metabolism, the drug should be used during pregnancy only when potential benefits justify possible risks to the fetus.

Fixed-combination ophthalmic preparations containing polymyxin B sulfate and other anti-infectives (i.e., bacitracin zinc, gramicidin, neomycin sulfate, trimethoprim sulfate) should be used with caution in nursing women.

Fixed-combination ophthalmic preparations containing polymyxin B sulfate, neomycin sulfate, and dexamethasone should be used with caution in nursing women.

The manufacturers of fixed-combination ophthalmic preparations containing polymyxin B sulfate, neomycin sulfate, bacitracin zinc, and hydrocortisone or hydrocortisone acetate state that a decision should be made whether to discontinue nursing or the ophthalmic preparation, taking into account the importance of the drug to the woman.

Fixed-combination otic preparations containing polymyxin B sulfate, neomycin sulfate, and hydrocortisone should be used with caution in nursing women.

Trimethoprim is distributed into milk. Because trimethoprim may interfere with folic acid metabolism, the drug should be used with caution in nursing women.

No enhanced messaging available.