Category: Antibiotics

Questions and Answers

What is the difference between the antibiotic Bactrim and the antibiotic nitrofurantoin?

I was diagnosed with a bladder infection. One doctor prescribed me Bactrim and another doctor prescribed me with nitrofurantoin?

Bactrim is in the classification of anti-infectives called sulfonamides and is a combination of sulfamethoxazole and trimethoprim called co-trimoxazole. It’s used to treat UTIs caused by strains of E. coli, Proteus, Klebsiella or Enterocobacter.

Nitrofurantoin (Macrobid, Macrodantin) is a miscellaneous anti-infective, no specific calssification, and is also used to treat UTIs caused by E. coli, certain strains of Klebsiella and Enterocobacter and also Staph a. and enterococci.

If you had a urine culture and the organism was identified as E. coli, Kelbsiella or Enterocobacter, then either one will work. Find out what is causing the infection.

How many mg of Bactrim did you take for a sinus infection?

I am 28 year old female. I am 5’7″ and weigh 130 lbs. I have a year old script for some bactrim and can’t remember how many mg I should take for a sinus infection. They are 800 mg pills.

Bactrim DS is one of many brand names for a common antibiotic combination containing trimethoprim (TMP) and sulfamethoxazole (SMX) in a fixed combination at a 1:5 ratio, 160 mg TMP plus 800 mg SMX, which is what you have. One year old is not too old.

The DS form is taken every twelve hours (twice a day) regardless of weight. The usual duration of therapy is five to ten days, with seven being average.

This assumes that you know that you are not allergic to sulfa medications like Septra.

Does Bactrim work for strep throat and or sinus infections?

Does anyone know if Bactrim works for strep throat and or sinus infections? Thanks.

Bactrim is a broad based spectrum antibiotic. It can be used to treat various infections. Including strep throat and sinus infections. But may not clear them up as effectively as an antibiotic designed specifically for the type of infection you have would.

How long does it take for Bactrim to expire?

I have a bottle of Bactrim I had filled on June 26th, 2009 but there’s not an expiration date on it that I can find… I heard antibiotics take around a year to expire, but I was wondering whether or not I can take them still…

Why would you take it? How do you know you have a bacterial infection without visiting a doctor? Please don’t overuse antibiotics/use with without a prescription, it will cause resistance, and you will be sorry when you really need it.

Can bactrim affect vitamin B12 or intrinsic factor in a baby’s body?

I need to find reliable sources that state that bactrim (or septra) can affect the level of vitamin B12 in a baby’s body 4-8 weeks old.

Or maybe if Bactrim can affect the intrinsic factor in a baby’s body.

Vit B12 is a key factor to prvent pernicious anemia.

Vit B12 is absorbed from specific receptors from the intestine with the help of the interensic factor.
Also, Bactrim is absorbed from the same receptors.
Hence, a competetion is created. Thus the level of Vit B12 enetering the blood stream is decreased.

The effects of lack of Vit B12 is more observed in babies since they do need a lot of vitamins and nutrition for their growth.

Can taking Bactrim for a UTI cause my tooth ache to become worse?

I have had tooth pain for a few days, but I started Bactrim for a UTI yesterday and coincidentally the tooth pain got worse. Is this a coincidence or is it possible that the antibiotic, for some weird reason, caused the pain to worsen?

Coincidence, actually the antibiotic will help your tooth pain if you have an infection or an abscess. It will kill the infection in your blatter as well as your mouth. Hope you feel better soon.

What will taking bactrim do to my baby if i am pregnant?

I don’t know if im pregnant for sure yet, but I take bactrim for my skin. What complications could happen if I don’t stop?

Bactrim is in the FDA pregnancy category C. This means that it is not known whether it will harm an unborn baby. This medication affects folic acid in your body, which is necessary for the normal development of a baby. Do not take without first talking to your doctor if you are pregnant or think you might be.

How long after taking Bactrim DS to get into a tanning bed.?

I was prescribed Bactrim for a UTI.My final dosage is tomarrow. How long do I need to wait before getting back in the tanning bed?

Also I know about the risks of skin cancer and tanning beds.So keep those kinds of answers/comments to yourself.Thanks in advance.

Bactrim DS is a drug that increases your skin’s sensitivity to the sun, and as the intensity of a tanning bed is very high, you may want to give yourself a couple days to let it clear from your system. If you are very fair skinned and/or not used to tanning, give it even longer.

What are the long term effects of Bactrim/Septra.?

My mother (she’s 50) has been on Bactrim for several years now due to reoccurent UTI caused by a bladder ulcer. What are the major concerns for taking this over the long term (other than bacteria resistant infections) Also she had an episode of tachycardia (160-172) for an hour and the next day she checked her B/P and it was 86/72. Her pulse is usually in the 60’s and her B/P is normally 110/70-ish. Could this have anything to do with her long term Bactrim use? (And yes I already told her to go to the Dr.’s, she is there at this moment…I am just trying to find out for my own information) Thank you everyone who answers.

Sulfamethoxazole (as in Bactrim, Septra, Septrin etc)

Adverse effects and treatment

Nausea, vomiting, anorexia, and diarrhoea are relatively common following the administration of sulfamethoxazole and other sulfonamides.

Hypersensitivity reactions to sulfonamides have proved a problem. Fever is relatively common, and reactions involving the skin may include rashes, pruritis, photosensitivity reactions, exfoliative dermatitis, and erythema nodosum. Severe, potentially fatal, skin reactions including toxic epidermal necrolysis and the Stevens-Johnson syndrome have occurred in patients treated with sulfonamides. Dermatitis may also occur from contact of sulfonamides with the skin. Systemic lupus erythematosus, particularly exacerbation of pre-existing disease, has also been reported.

Nephrotoxic reactions including interstitial nephritis and tubular necrosis, which may result in renal failure, have been attributed to hypersensitivity to sulfamethoxazole. Lumbar pain, haematuria, oliguria, and anuria may also occur due to crystallisation in the urine of sulfamethoxazole or its less soluble acetylated metabolite. The risk of crystalluria can be reduced by the administration of fluids to maintain a high urine output. If necessary, alkalinisation of the urine by administration of sodium bicarbonate may increase solubility and aid the elimination of sulfonamides.

Blood disorders have occasionally occurred during treatment with the sulfonamides including sulfamethoxazole, and include agranulocytosis, aplastic anaemia, thrombocytopenia, leucopenia, hypothrombinaemia, and eosinophilia. Many of these effects on the blood may result from hypersensitivity reactions. Sulfonamides may rarely cause cyanosis due to methaemoglobinaemia. Acute haemolytic anaemia is a rare complication which may be associated with glucose-6-phosphate dehydrogenase deficiency.

Other adverse effects which may be manifestations of a generalised hypersensitivity reaction to sulfonamides include a syndrome resembling serum sickness, liver necrosis, hepatomegaly and jaundice, myocarditis, pulmonary eosinophilia and fibrosing alveolitis, and vasculitis including polyarteritis nodosa. Anaphylaxis has been reported only very rarely.

Other adverse reactions that have been reported after the administration of sulfamethoxazole or other sulfonamides include hypoglycaemia, hypothyrodism, neurological reactions including aseptic meningitis, ataxia, benign intracranial hypertension, convulsions, dizziness. drowsiness, fatigue, headache, insomnia, mental depression, peripheral or optic neuropathies, psychoses, tinnitus, vertigo, and pancreatitis.

Sulfonamides may displace serum-bound biluribin, resulting in jaundice and kernicterus in premature neonates.

As with other antimicrobials, sulfamethoxazole may cause alterations of the bacterial flora in the gastrointestinal tract. There is, therefore, the possibility, although it appears to be small, that pseudomembranous colitis may occur.

Slow acetylators of sulfamethoxazole may be at greater risk of adverse reactions than fast acetylators.


In patients receiving sulfamethoxazole, adequate fluid intake is necessary to reduce the risk of crystalluria; the daily urine output should be 1200 to 1500 mL or more. The administration of compounds which render the urine acidic may increase the risk of crystalluria; the risk may be reduced with alkaline urine.

Treatment with sulfonamides should be discontinued immediately a rash appears because of the danger of severe allergic reactions such as the Stevens-Johnson syndrome.

Sulfamethoxazole should be given with care to patients with renal or hepatic impairment and is contra-indicated in patients with severe renal or hepatic failure or with blood disorders. Dosage reduction may be necessary in renal impairment. Complete blood counts and urinalyses with microscopic examination should be carried out particularly during prolonged therapy. Sulfamethoxazole should not be given to patients with a history of hypersensitivity to sulfonamides as cross-sensitivity may occur between drugs of this group. Care is generally advisable in patients with a history of allergy or asthma. Caution is also needed in the elderly, who may be more likely to have other risk factors for reactions. Some authorities consider sulfamethoxazole to be contra-indicated in lupus erythematosus as it may exacerbate the condition. Patients with glucose 6-phosphate dehydrogenase deficiency may be at risk of haemolytic reactions.

Sulfamethoxazole and other sulfonamides are not usually given to infants within 1 to 2 months of birth because of the risk of kernicterus; for the same reason, they are generally contra-indicated in women prior to delivery, and in breast-feeding mothers.

Patients with Aids may be particularly prone to adverse reactions, especially when sulfamethoxazole is given in combination with trimethoprim as co-trimoxazole.

Sulfonamides have been reported to interfere with some diagnostic tests, including those for urea, creatinine, and urinary glucose and urobilinogen.

My daughter was put on Bactrim last night for a bladder infection?

shes 4 yrs old has had 3 doses now she is coughing,has red itchy eyes and bright red cheeks. Do you think this could be a sign of an allergic reaction
Ive read into it to see and some of them seem like they could be allergy symptoms, Does anyone out there have a Bactrim allergy and if so what does it do to you. Thank you!

Hon, that definitely sounds like a more severe type allergic reaction. Please call her doctor right away about this as he or she will have to switch her to another medicine. As an allergic person myself, I know from experience that these reactions can do more harm than good. Don’t give her any more of the medicine until you check it out with her doctor. I hope you get this resolved quickly…Good luck!
Here is a website that will give you more insight into side effects for bactrim: