Bactrim Dosage

by on April 21, 2012

Bactrim (Sulfamethoxazole and Trimethoprim) is an antibiotic available in both liquid suspension and tablets that fights various infections such as ear infections, bronchitis and urinary infections that are all caused by bacteria.

The tablet form of Bactrim is available in two different strengths – regular strength and double strength. Its regular strength contains 400 mg sulfamethoxazole and 80 mg trimethoprime while the double strength contains 800 mg sulfamethoxazole and 160 mg trimethoprim.

The tablet form is generally used with adults with dosage depending on the patient’s size. Conversely, the liquid suspension form of Bactrim is generally used with children. The children’s dosage is based on weight, height and age. The physician’s instructions on dosage should always be followed.

Missed Doses and Bactrim Overdoses

Any missed dose of Bactrim should be taken as soon as it is remembered by the patient. If the next scheduled dose time is almost at hand, the missed dose should be skipped. Extra medication should NOT be taken to make up the missed dose.

Patients suffering from an overdose may experience headaches, yellowing of skin or eyes, fever, fainting, confusion, blood in urine, loss of appetite, vomiting, nausea, drowsiness or dizziness. If a patient suspects an overdose of Bactrim, they should contact the Poison Control Center immediately at 1-800-222-1222.


Bactrim should be kept in its original sealed container until use – in the blister pack for tablets or in a closed bottle for the oral suspension. Keep the packages in a cool, dry place out of direct sunlight. This medication, as well as any others, should be NOT be stored in bathrooms or near a sink. This medication may seriously hurt young children so it should be stored well out of reach in a locked cabinet or cupboard. The entire prescription should be used by a patient even if they begin to feel better before completion.