Key takeaways
- Bactrim is prescribed to treat bacterial infections in adults and some children. The specific dosage depends on the type and severity of the infection. Your doctor will determine the appropriate dosage and duration of treatment.
- The medication comes in different strengths, and the dosage may need to be adjusted based on individual factors like kidney function or body weight, so it’s important to follow your doctor’s instructions. Never change your dosage without consulting a healthcare professional.
- While Bactrim is effective against bacterial infections, it is not appropriate for treating viral or fungal infections, such as yeast infections.
Overview
This article describes Bactrim’s dosages, strengths, and how to take it. You’ll also find information on cost savings and coupon options for Bactrim. If you want to know more about Bactrim, see this overview article. It covers details about the drug’s uses and side effects, ways to save on cost, and more.
Bactrim is a brand-name medication that comes as an oral tablet. It’s available in a generic version called sulfamethoxazole/trimethoprim. This article describes dosages of Bactrim.
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Form and strengths of Bactrim
Bactrim comes as follows:
- Form: a tablet that you swallow
- Strengths:
- 400 milligrams (mg) sulfamethoxazole/80 mg trimethoprim
- 800 mg sulfamethoxazole/160 mg trimethoprim
Dosage of Bactrim
This article describes the recommended dosages for Bactrim. The drugmaker provides these dosages.
If your doctor prescribes this medication, you should follow the dosage they prescribe. Your doctor will determine the dosage that best meets your needs. Do not change your dosage of Bactrim without your doctor’s recommendation.
Usual recommended dosages of Bactrim in adults
Bactrim is approved to treat certain types of bacterial infections in adults.
Your doctor will determine how long you need to take Bactrim. This will depend on what type of infection you have and how severe it is.
The following table contains the recommended dosages of Bactrim.
| Purpose | Recommended dose | Dosage schedule |
|---|---|---|
| treat urinary tract infection (UTI) | 1 Bactrim double-strength (DS) tablet* or 2 Bactrim tablets† | twice per day for 10 to 14 days |
| treat shigellosis | 1 Bactrim DS tablet* or 2 Bactrim tablets† | twice per day for 10 to 14 days |
| treat chronic bronchitis flare-ups | 1 Bactrim DS tablet or 2 Bactrim tablets | twice per day for 14 days |
| treat pneumocystis pneumonia | your doctor will determine your dose based on your body weight | four times per day for 14 to 21 days |
| prevent pneumocystis pneumonia | 1 Bactrim DS tablet | once per day for as long as your doctor prescribes |
| treat traveler’s diarrhea | 1 Bactrim DS tablet or 2 Bactrim tablets | twice per day for 5 days |
* Bactrim double-strength (DS) tablets contain 800 milligrams (mg) sulfamethoxazole/160 mg trimethoprim.
† Bactrim tablets contain 400 mg sulfamethoxazole/80 mg trimethoprim.
Dosages of Bactrim in children
Bactrim is approved to treat certain bacterial infections in some children. This includes children ages 2 months and older. Children under the age of 2 months should not take Bactrim.
The following table contains the recommended dosages of Bactrim in milligrams (mg) and kilograms (kg).*
| Purpose | Recommended dose | Dosage schedule |
|---|---|---|
| treat UTI | 40 mg/kg of body weight sulfamethoxazole and 8 mg/kg of body weight trimethoprim | divided into two doses throughout the day for 10 days |
| treat shigellosis | 40 mg/kg of body weight sulfamethoxazole and 8 mg/kg of body weight trimethoprim | divided into two doses throughout the day for 5 days |
| treat middle ear infection | 40 mg/kg of body weight sulfamethoxazole and 8 mg/kg of body weight trimethoprim | divided into two doses throughout the day for 10 days |
| treat pneumocystis pneumonia | 75 to 100 mg/kg of body weight sulfamethoxazole and 15 to 20 mg/kg of body weight trimethoprim | divided into four doses throughout the day for 14 to 21 days |
| prevent pneumocystis pneumonia | your child’s doctor will determine the dose based on your child’s height and body weight | twice per day for as long as your doctor prescribes |
* For reference, 1 kg is about 2.2 pounds (lb). The unit mg/kg represents milligrams per kilogram.
Dosage adjustments for Bactrim
Your doctor will prescribe a dosage of Bactrim based on several factors. These include:
- the specific condition being treated and how severe it is
- other health conditions you may have
- body weight (in children and some adults)
Missed dose of Bactrim
Talk with your doctor or pharmacist right away if you realize you forgot to take a dose of Bactrim. They may advise you to take the missed dose. Or they may advise you to skip it and take your next dose as scheduled.
For tips on how to plan your doses of Bactrim and avoid missing a dose, read this article. You could also try:
- downloading a reminder app on your phone
- setting an alarm
- putting a note where you’ll see it, such as on your calendar, bathroom mirror, or bedside table
Frequently asked questions about Bactrim
Answers to some commonly asked questions about Bactrim and its dosage are as follows.
What is Bactrim’s dosage for skin infections?
Bactrim’s dosage for skin infections may vary. Bactrim isn’t specifically approved to treat bacterial skin infections, but your doctor may prescribe it off-label for this condition. (With off-label use, doctors prescribe drugs for conditions other than what they’re approved to treat.)
Because Bactrim isn’t approved for this use, the drug’s manufacturer doesn’t recommend a specific dosage. If your doctor prescribes Bactrim for your skin infection, they’ll determine the right dosage for you.
For more details about Bactrim or other medications to treat skin infections, talk with your doctor or pharmacist.
What is Bactrim’s dosage for yeast infections?
There is no dosage of Bactrim to treat yeast infections (also known as candidiasis). This is because Bactrim is an antibacterial or antibiotic drug, which means it’s only effective for treating bacterial infections.
A yeast infection is a fungal infection caused by Candida fungi. If you have a yeast infection, your doctor will likely prescribe an antifungal medication to treat it, such as fluconazole (Diflucan).
For more information about medications for yeast infections, see this article. You can also talk with your doctor or pharmacist.
Is there a 3-day dosage of Bactrim for a urinary tract infection (UTI)?
It depends. In some cases, doctors may prescribe Bactrim for 3 days. However, the recommended dosage of Bactrim for a UTI is one Bactrim double-strength (DS) tablet* or 2 Bactrim tablets† twice per day for 10 to 14 days.
If you have questions about how long you need to take Bactrim, talk with your doctor.
* Bactrim double-strength (DS) tablets contain 800 milligrams (mg) sulfamethoxazole/160 mg trimethoprim.
† Bactrim tablets contain 400 mg sulfamethoxazole/80 mg trimethoprim.
Is Bactrim taken long term?
No, doctors don’t typically prescribe Bactrim as a long-term treatment. It’s usually recommended for short-term use.
If you have questions about how long you should take Bactrim, talk with your doctor.
How Bactrim is taken
You’ll typically swallow Bactrim oral tablet twice per day, or as prescribed by your doctor. You can take the drug with or without food. Taking it with food can lower your risk of stomach upset.
Your doctor may advise that you take this medication around the same time each day. This helps keep a consistent amount of the drug in your body. And that can help the drug work more effectively.
The drugmaker hasn’t specified whether Bactrim tablets can be cut, crushed, or dissolved. If it’s hard for you to swallow tablets, view this article. It provides suggestions on how to swallow medications that come in pill form.
Also, be sure to talk with your doctor or pharmacist if you’re having difficulty taking your medication. They can offer recommendations about taking it.
Bactrim coupon
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Get free cardOverdose of Bactrim
It’s important that you do not take more Bactrim than your doctor prescribes. Doing so can lead to harmful effects.
Symptoms of Bactrim overdose
Symptoms of an overdose can include:
- loss of appetite
- nausea
- vomiting
- drowsiness
- loss of consciousness
- fever
- blood in the urine
- headache
- confusion
What to do if you take too much Bactrim
If you think you’ve taken too much Bactrim, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have severe symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.