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Sulfamethoxazole / Trimethoprim Dosage

Applies to the following strength(s): 400 mg-80 mg ; 800 mg-160 mg ; 200 mg-40 mg/5 mL ; 80 mg-16 mg/mL

The information at Drugs.com is not a substitute for medical advice. Always consult your doctor or pharmacist.

Usual Adult Dose for Pneumocystis Pneumonia

Oral: 15 to 20 mg/kg/day (based on the trimethoprim component) orally daily in 4 equally divided doses every 6 hours for 14 to 21 days

IV: 15 to 20 mg/kg/day (based on the trimethoprim component) IV daily in 3 or 4 equally divided doses every 6 to 8 hours for up to 14 days

Comments:
-IV formulation: One investigator noted that a total daily dose of 10 to 15 mg/kg was sufficient in 10 adult patients with normal renal function.

Use: For the treatment of documented Pneumocystis jiroveci pneumonia

Usual Adult Dose for Pneumocystis Pneumonia Prophylaxis

-Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally once a day
-Maximum dose: The total daily dose should not exceed 1600 mg sulfamethoxazole and 320 mg trimethoprim

Use: For prophylaxis against P jiroveci pneumonia in individuals who are immunosuppressed and considered to be at an increased risk of developing P jiroveci pneumonia

Usual Adult Dose for Urinary Tract Infection

Oral: Sulfamethoxazole-trimethoprim 800 mg-160 mg orally every 12 hours for 10 to 14 days

IV:
Severe infection: 8 to 10 mg/kg/day (based on the trimethoprim component) IV in 2 to 4 equally divided doses every 6, 8, or 12 hours for up to 14 days; maximum recommended dose is 960 mg (based on the trimethoprim component) per day

Use: For the treatment of severe or complicated urinary tract infections due to susceptible strains of Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis, and Proteus vulgaris

Usual Adult Dose for Shigellosis

Oral: Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet or 2 single strength tablets) orally every 12 hours for 5 days

IV:
Severe infection: 8 to 10 mg/kg/day (based on the trimethoprim component) IV in 2 to 4 equally divided doses every 6, 8, or 12 hours for 5 days; maximum recommended dose is 960 mg (based on the trimethoprim component) per day

Comments:
-The patient should be instructed to use extraordinary sanitary precautions since Shigella is transmitted by the fecal-oral route, primarily by hand-to-mouth contact.

Use: For the treatment of enteritis caused by susceptible strains of Shigella flexneri and Shigella sonnei

Usual Adult Dose for Bronchitis

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet or 2 single strength tablets) orally every 12 hours for 14 days

Use: For acute exacerbations of chronic bronchitis due to susceptible strains of Streptococcus pneumoniae or Haemophilus influenzae when the physician deems that sulfamethoxazole and trimethoprim could offer some advantage over the use of a single antimicrobial agent

Usual Adult Dose for Traveler's Diarrhea

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet or 2 single strength tablets) orally every 12 hours for 5 days

Use: For the treatment of traveler's diarrhea due to susceptible strains of enterotoxigenic E coli

Usual Adult Dose for Pyelonephritis

Uncomplicated: Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally every 12 hours for 10 days

Use: Uncomplicated pyelonephritis (off-label use)

Usual Adult Dose for Otitis Media

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally every 12 hours for 10 to 14 days

Use: Otitis media (off-label use in adults)

Usual Adult Dose for Cystitis Prophylaxis

Sulfamethoxazole-trimethoprim 400 mg-80 mg (1 single-strength tablet) orally once a day or 3 times a week at bedtime

Comments:
-Some clinicians recommend that their female patients take this low dose postcoitally or 3 times a week, whichever is less frequent. Therapy should be continued for as long as the patient is at risk for infection.

Use: Cystitis prophylaxis (off-label use)

Usual Adult Dose for Granuloma Inguinale

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally 2 times a day for at least 3 weeks

Use: Granuloma inguinale (off-label use)

Usual Adult Dose for Meningitis

10 to 20 mg/kg (based on the trimethoprim component) IV every 6 to 12 hours

Comments:
Use in combination with chloramphenicol is an alternative for patients with beta-lactam allergy

Use: Bacterial meningitis (off-label use)

Usual Adult Dose for Nocardiosis

Cutaneous infection: 5 to 10 mg/kg/day (based on the trimethoprim component) IV or orally in 2 to 4 divided doses

Severe infection (pulmonary/cerebral): 15 mg/kg/day (based on the trimethoprim component) in 2 to 4 divided doses for 3 to 4 weeks, then 10 mg/kg/day (based on the trimethoprim component) in 2 to 4 divided doses; may be initiated IV and converted to oral therapy (frequently converted to approximate dosages of oral solid dosage forms: 2 double strength tablets [320 mg-1600 mg] every 8 to 12 hours)

Duration: Not well standardized; most experts recommend at least 6 months for local disease in immunocompetent patients and 6 to 12 months or more for immunocompromised patients or patients with CNS disease

Comments:
-Off-label use.
-Measurement of serum levels are advisable. Maximum plasma concentrations (Cmax) of 100 to 150 mcg/mL are recommended. Severe disease is often treated with addition of other agents, such as ceftriaxone, imipenem, or amikacin.

Usual Adult Dose for Prostatitis

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally every 12 hours

Duration: Acute, 10 to 14 days; chronic, 1 to 3 months

Comments:
-Off-label use.

Usual Adult Dose for Sinusitis

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally every 12 hours

Duration: 10 to 14 days; in some cases of recurrent or refractory sinusitis, therapy may be required for up to 3 to 4 weeks

Comments:
-Off-label use.

Usual Adult Dose for Toxoplasmosis

5 mg/kg (based on the trimethoprim component) IV every 12 hours

Duration: 4 weeks to 6 months or more, depending on the nature and severity of the infection; patients with AIDS are usually given high dose therapy for 4 to 6 weeks then maintained on oral trimethoprim-sulfamethoxazole for life

Comments:
-Off-label use.

Usual Adult Dose for Toxoplasmosis - Prophylaxis

Acute bacterial exacerbation of chronic bronchitis: Trimethoprim-sulfamethoxazole 160 mg-800 mg (1 double-strength tablet) orally every 12 hours for 14 days

Usual Adult Dose for Upper Respiratory Tract Infection

Sulfamethoxazole-trimethoprim 800 mg-160 mg (1 double strength tablet) orally every 12 hours

Comments:
-Off-label use.

Usual Pediatric Dose for Otitis Media

2 months or older:
4 mg/kg (based on the trimethoprim component) orally every 12 hours for 10 to 14 days

Use: For the treatment of acute otitis media in pediatric patients due to susceptible strains of Streptococcus pneumoniae or Haemophilus influenzae when in the judgment of the physician sulfamethoxazole and trimethoprim offers some advantage over the use of other antimicrobial agents; sulfamethoxazole and trimethoprim is not indicated for prophylactic or prolonged administration in otitis media

Usual Pediatric Dose for Urinary Tract Infection

2 months or older:
-Oral: 4 mg/kg (based on the trimethoprim component) orally every 12 hours for 10 to 14 days
-IV:
Severe infection: 8 to 10 mg/kg/day (based on the trimethoprim component) IV in 2 to 4 equally divided doses every 6, 8, or 12 hours for 10 to 14 days; maximum recommended dose is 960 mg (based on the trimethoprim component) per day

Use: For the treatment of severe or complicated urinary tract infections due to susceptible strains of Escherichia coli, Klebsiella species, Enterobacter species, Morganella morganii, Proteus mirabilis, and Proteus vulgaris

Usual Pediatric Dose for Shigellosis

2 months or older:
-Oral: 4 mg/kg (based on the trimethoprim component) orally every 12 hours for 5 days
-IV:
Severe infection: 8 to 10 mg/kg/day (based on the trimethoprim component) IV in 2 to 4 equally divided doses every 6, 8, or 12 hours for 5 days; maximum recommended dose is 960 mg (based on the trimethoprim component) per day

Comments:
-The patient should be instructed to use extraordinary sanitary precautions since Shigella is transmitted by the fecal-oral route, primarily by hand-to-mouth contact.

Use: For the treatment of enteritis caused by susceptible strains of Shigella flexneri and Shigella sonnei

Usual Pediatric Dose for Pneumocystis Pneumonia

2 months or older:
15 to 20 mg/kg/day (based on the trimethoprim component) orally or IV every 24 hours given in 4 equally divided doses every 6 hours for 14 to 21 days

Use: For the treatment of documented Pneumocystis jiroveci pneumonia

Usual Pediatric Dose for Pneumocystis Pneumonia Prophylaxis

2 months or older:
75 mg/m2 (based on the trimethoprim component) orally 2 times a day, on 3 consecutive days per week

Maximum dose: The total daily dose should not exceed 320 mg (based on the trimethoprim component)

Use: For prophylaxis against P. jiroveci pneumonia in individuals who are immunosuppressed and considered to be at an increased risk of developing P jiroveci pneumonia

Renal Dose Adjustments

CrCl less than 15 mL/min: Contraindicated
CrCl 15 to 30 mL/min: Reduce dose by 50%.
CrCl greater than 30 mL/min: Use standard dosing.

Liver Dose Adjustments

Severe hepatic impairment: Contraindicated
Mild to moderate hepatic impairment: Caution is recommended.

Dose Adjustments

IV administration should be restricted to use during periods in which the patient is unable to accept oral therapy.

Precautions

Safety and efficacy have not been established in patients younger than 2 months of age.

Consult WARNINGS section for additional precautions.

Dialysis

Peritoneal dialysis is not effective and hemodialysis is only moderately effective in eliminating trimethoprim (TMP) and sulfamethoxazole (SMX). Because both TMP and SMX are moderately removed by hemodialysis, it is recommended that the combination drug be given after dialysis sessions if doses are scheduled to be given on the days the patient is dialyzed.

Other Comments

Administration advice:
-The oral formulation should be administered with food and/or liquids.
-Adequate fluid intake and urinary output should be maintained to prevent crystalluria.
-Oral syrup is recommended for use in children; the oral tablets are not considered suitable for children under 12 years of age.

General:
-Sulfonamides should not be used for the treatment of infections due to Group A beta-hemolytic streptococci because the organisms may not be eradicated.
-Not all products are approved for the same indications. Refer to the manufacturer product information for indications.

Reconstitution/preparation techniques:
-The IV formulation should be diluted prior to infusion.

Storage requirements:
-The concentrate injection ampules should be stored below 30 degrees Celsius but not refrigerated.
-The diluted solution for IV infusion should be used as soon as possible after preparation and within 24 hours.
-The prepared solution should not be refrigerated.
-The reconstituted IV formulation should be discarded if it has been stored at low temperatures due to the potential for precipitation.

IV compatibility:
-The manufacturer product information should be consulted.

Monitoring:
-Urine analysis and renal function tests should be performed during long term therapy, particularly in patients with reduced renal function.
-Regular blood counts are advisable in patients on long-term therapy, in those predisposed to folate deficiency, in malabsorption syndromes, malnutrition states, or during the treatment of epilepsy with anticonvulsant drugs.

IV compatibility:
-The manufacturer product information should be consulted.

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