Trimethoprim

• The most prescribed antibiotic for bladder infections is Trimethoprim, for its low-resistance rate. It comes in an oral tablet and should be taken on an empty stomach. You can buy it under the brand names Proloprim, Monotrim or Tripim. Trimethroprim is a short-term antibiotic because long-term use has been proven to be a factor in the development of a serious blood disorder. Dofetilide, methortrexate and cyclosporine should never be taken if you are already taking trimethoprim. It can cause unnecessary side effects.
  
  

Trimethoprim/sulfamethoxazole

• Bladder infections are also treated with a combination of trimethorprim and another antibiotic called sulfamethoxazole. The two drugs together prevent two consecutive processes in bacteria reproduction. This antibiotic combination may be taken orally or injected and will begin working within 24 hours. If you are buying trimethorprim/sufamethoxazole, you will find it under the brand names of Bactrim, Septra or Cotrim. Tell your health care provider if you are also taking warfarin, procainamdie or suflonlylureas, because these can cause severe drug interactions with trimethoprim/sulfamethoxazole.
  
  

Amoxicillin

• Penicillin is one of the most well-known antibiotics and amoxicillin is a form of penicillin. From gonorrhea to ear infections, amoxicillin is used to prevent many different types of infections. It is taken orally, either in the form of a pill or a suspension liquid. It is more effective when taken with food. To avoid dangerous drug interactions, do not take amoxicillin if you are also taking methotreate, probenecid or tetracyclines. If you are taking an oral contraceptive, use other birth control during your bladder infection. Amoxicillin reduces the effectiveness of oral contraceptives.
  
  

Nitrofurantoin

• Nitrofaurantoin, often sold as Macrobid and Macrodantin, is another antibiotic that may be prescribed for bladder infection. This antibiotic comes as a suspension liquid and should be taken with food or milk. Avoid combining nitrofaurantoin with probenecid or magnesium salts to avoid adverse reactions. A common side effect of this antibiotic is discolored urine, which may turn dark brown or orange.
  
  

Ampicillin

• Ampicillin is another antibiotic that will turn your urine dark brown or orange as it disarms the bacteria causing your bladder infection. It is sold as Ampicillin Sodium or Principen. Take the tablets orally on anempty stomach. Tell your health care provider if you are already taking allopurinol, atenolol or tetracyclines, because he will want to prescribe something else. If you take these drugs with ampicillin, you may experience unnecessary and dangerous side effects. Like nitrofaurantoin, ampicillin will make oral contraceptives to stop working. Therefore, if you are taking them, use another form of birth control until your bladder infection is cured.