Bactrim® DS (
sulfamethoxazole/trimethoprim) is a prescription antibiotic approved to treat a variety of different infections. In addition to treating infections, it is approved to prevent one particular infection,
Pneumocystis carinii pneumonia, in people with a weakened immune system.
The "DS" stands for "double strength." Bactrim DS contains exactly twice as much of the active ingredients as regular Bactrim. There are no other important differences between these two forms. Taking two regular
Bactrim tablets is the same as taking one Bactrim DS tablet.
(Click Bactrim Uses for more information on what this medication is used for, including possible off-label uses.)
Brand-name Bactrim DS is manufactured by Mutual Pharmaceutical Company, Inc. and is marketed and distributed by AR Scientific. Generic versions are made by different manufacturers.
Bactrim DS contains two different antibiotic medications: sulfamethoxazole and trimethoprim.
Combining these two antibiotics increases their effectiveness and decreases the chance of antibiotic resistance (when bacteria develop the ability to resist antibiotics).
Sulfamethoxazole belongs to a group of drugs known as sulfonamides ("sulfa" drugs). Trimethoprim does not belong to a specific class of medications. These two antibiotics work in different but similar ways. Essentially, both work by inhibiting the production of
folic acid in bacteria, although they work in different stages of folic acid production. Folic acid is important for making proteins and DNA. Because humans obtain folic acid from the diet (and bacteria cannot), human cells are less affected by Bactrim DS.
When and How to Take Bactrim DS
Some general considerations for those taking this antibiotic include the following:
- Bactrim DS comes in tablet form. It is taken by mouth, usually twice a day, although it is taken as frequently as four times daily or as infrequently as once daily for certain uses.
- You can take this medication with food or on an empty stomach. If Bactrim DS bothers your stomach, try taking it with food.
- Bactrim DS can be taken at any time of the day; however, make sure to take the medication at the same time(s) each day. For instance, if you take it twice daily, it is best to evenly space the doses, taking a dose every 12 hours.
- For the medication to work properly, it must be taken as prescribed. Bactrim DS will not work if you stop taking it too soon.
The dose of Bactrim DS your healthcare provider recommends will vary, depending on a number of factors, including:
- The type of infection and bacteria
- Your height and weight (for some uses)
- Other medical conditions you may have
- Other medications you are currently taking.
As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
Side Effects of Bactrim DS
As with any medicine, side effects are possible with Bactrim DS. However, not everyone who takes the drug will experience side effects. In fact, most people tolerate it quite well. Serious side effects are less common.
Some of the common side effects include but are not limited to:
- Rashes
- Nausea
- Vomiting
- Loss of appetite
- Itching.
(Click Bactrim Side Effects to learn more, including potentially serious side effects you should report immediately to your healthcare provider.)
What Should I Tell My Healthcare Provider?
You should talk with your healthcare provider prior to taking this medication if you have:
- Anemia
- Asthma
- Glucose-6-phosphate dehydrogenase deficiency
- A folic acid deficiency
- Phenylketonuria (PKU)
- A thyroid disorder
- Porphyria
- HIV or AIDS
- Kidney disease, such as kidney failure (renal failure)
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- An arrhythmia known as long QT syndrome
- Any other allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about any other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
What If I Take an Overdose of Bactrim DS?
People who take an overdose may experience effects such as:
- Loss of appetite
- Abdominal (stomach) pain
- Nausea
- Vomiting
- Dizziness
- Headaches
- Drowsiness
- Unconsciousness
- Fever
- Blood in the urine
- Yellowing of the whites of the eyes or skin (jaundice)
- Confusion.
If you happen to overdose on Bactrim DS, seek immediate medical attention.
What Should I Do If I Miss a Dose?
If you do not take your
Bactrim DS as scheduled, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose of the medication. Try not to miss doses, as this increases the risk of developing an antibiotic-resistant infection.
Bactrim DS tablets contain 800 mg of sulfamethoxazole and 160 mg of trimethoprim per tablet. This is exactly twice as much of the active ingredients compared to regular Bactrim (400 mg of sulfamethoxazole and 80 mg of trimethoprim).
How Should Bactrim DS Be Stored?
Store this medication at room temperature, away from moisture and heat. Make sure to keep it in an airtight container. Keep this and all medications out of the reach of children.
Generic Availability of Bactrim DS
Currently, this medication is available in generic form
(see Generic Bactrim for more information).
