trimethoprim

section name header

Pronunciation ⬇

trye-METH-oh-prim

Indications ⬆ ⬇

REMS

Treatment of uncomplicated urinary tract infections.
Treatment of uncomplicated otitis media in children.

Unlabeled Use:

Prophylaxis of chronic recurrent urinary tract infections.
Treatment of head lice.
With dapsone in the management of mild to moderate Pneumocystis jirovecii pneumonia (PCP).

Action ⬆ ⬇

Interferes with bacterial folic acid synthesis.

Therapeutic Effects:

Bactericidal action against susceptible organisms.

Spectrum:

Some gram-positive pathogens, including:
- Staphylococcus saprophyticus.
Gram-negative spectrum includes the following Enterobacteriaceae:
- Enterobacter,
- Escherichia coli,
- Klebsiella pneumoniae,
- Proteus mirabilis,
Also active against Pneumocystis jiroveci.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed following oral administration.

Distribution: Widely distributed. Crosses the placenta and is distributed into breast milk in high concentrations.

Metabolism/Excretion: 80% excreted unchanged in the urine; 20% metabolized by the liver.

Half-life: 8–11 hr (↑ in renal impairment).

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity
Megaloblastic anemia secondary to folate deficiency.

Use Cautiously in:

Renal impairment (dose ↓ required if CCr 30 mL/min)
Debilitated patients
Severe hepatic impairment
Folate deficiency
OB: Lactation: Pedi: Pregnancy, lactation, or children <12 yr (safety as a single agent not established).

Adv. Reactions/Side Effects ⬆ ⬇

GI: altered taste, epigastric discomfort, glossitis, nausea, vomiting, drug-induced hepatitis.

Derm: pruritus, rash.

Hemat: megaloblastic anemia, neutropenia, thrombocytopenia.

Misc: fever.

Interactions ⬆ ⬇

Drug-Drug:

↑risk of folate deficiency when used with phenytoin ormethotrexate.
↑risk of bone marrow depression when used with antineoplastics or radiation therapy.
Rifampin may ↓ effectiveness by ↑ elimination.

Route/Dosage ⬆ ⬇

Treatment of Urinary Tract Infections

PO (Adults and Children 12 yr): 100 mg q 12 hr or 200 mg as a single daily dose.

Treatment of Otitis Media

PO (Children >6 mos): 5 mg/kg q 12 hr.

Prophylaxis of Chronic Urinary Tract Infections

PO (Adults): 100 mg/day as a single dose (unlabeled).

Pneumocystis jirovecii Pneumonia

PO (Adults): 20 mg/kg/day with 100 mg dapsone daily for 21 days (unlabeled).

Renal Impairment

PO (Adults): CCr 15–30 mL/min — 50 mg q 12 hr (for urinary tract infections.

Implementation ⬆ ⬇

PO: Administer on an empty stomach, at least 1 hr before or 2 hr after meals, with a full glass of water. May be administered with food if GI irritation occurs.

US Brand Names ⬆ ⬇

Primsol

Classifications ⬆ ⬇

Therapeutic Classification: anti-infectives

Pharmacologic Classification: folate antagonists

Availability ⬆ ⬇

(Generic available)

Tablets: 100 mg;
Oral solution (bubblegum flavor): 50 mg/5 mL;
In combination with: sulfamethoxazole. See Trimethoprim/Sulfamethoxazole monograph.

Time/Action Profile ⬆ ⬇

(blood levels)
ROUTE ONSET PEAK DURATION
PO rapid 1–4 hr 12–24 hr

Assessment ⬆ ⬇

Assess patient for urinary tract infection (fever, cloudy urine, frequency, urgency, pain and burning on urination) or other signs of infection at beginning of and throughout therapy.
Obtain specimens for culture and sensitivity prior to initiating therapy. First dose may be given before receiving results.
Monitor intake and output ratios. Fluid intake should be sufficient to maintain urine output of at least 1200–1500 mL daily.
Lab Test Considerations:
May produce elevated serum bilirubin, creatinine, BUN, AST, and ALT.
Monitor CBC and urinalysis periodically throughout therapy. Therapy should be discontinued if blood dyscrasias occur.

Pot. Nursing Diagnoses ⬆ ⬇

Risk for infection (Indications, Side Effects).

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication and to finish medication completely as directed, even if feeling better. Take missed doses as soon as remembered, with subsequent doses spaced evenly apart. Advise patient that sharing of this medication may be dangerous.
Advise patient to notify health care professional if skin rash, sore throat, fever, mouth sores, or unusual bleeding or bruising occurs. Leucovorin (folinic acid) may be administered if folic acid deficiency occurs.
Instruct patient to notify health care professional if symptoms do not improve.
Emphasize the importance of routine follow-up exams to evaluate progress.

Evaluation/Desired Outcomes ⬆ ⬇

Resolution of the signs and symptoms of infection. Therapy is usually required for 10–14 days for resolution of urinary tract infection.
Decreased incidence of urinary tract infections during prophylactic therapy.

Code ⬆

NDC Code^*
40032- Novel Laboratories, Inc.
40032-330- Trimethoprim 40032-330-24- 100 TABLET in 1 BOTTLE (40032-330-24)
42291- AvKARE, Inc.
42291-845- Trimethoprim 42291-845-90- 90 TABLET in 1 BOTTLE (42291-845-90)
43386- Lupin Pharmaceuticals,Inc.
43386-330- Trimethoprim 43386-330-01- 100 TABLET in 1 BOTTLE (43386-330-01)
51407- Golden State Medical Supply, Inc.
51407-257- Trimethoprim 51407-257-01- 100 TABLET in 1 BOTTLE (51407-257-01)
51862- Mayne Pharma
51862-486- Trimethoprim 51862-486-01- 100 TABLET in 1 BOTTLE (51862-486-01)
63629- Bryant Ranch Prepack
63629-7731- Trimethoprim 63629-7731-1- 30 TABLET in 1 BOTTLE (63629-7731-1)
63629- Bryant Ranch Prepack
63629-7731- Trimethoprim 63629-7731-2- 10 TABLET in 1 BOTTLE (63629-7731-2)
63629- Bryant Ranch Prepack
63629-7731- Trimethoprim 63629-7731-3- 45 TABLET in 1 BOTTLE (63629-7731-3)
71297- Allegis Holdings, LLC
71297-500- PrimSol 71297-500-16- 473 mL in 1 BOTTLE, PLASTIC (71297-500-16)
71297- Allegis Holdings, LLC
71297-500- PrimSol 71297-500-20- 20 mL in 1 BOTTLE, PLASTIC (71297-500-20)