Antibiotics are used to eradicate bacteria that cause infections.  If you have a bacterial infection, you need the right antibiotic for that specific infection.

Antibiotics are not effective against fungal infections or viruses such as those that cause the common cold or influenza.  Overuse of antibiotics, especially in situations where they are not effective, has been implicated in the development of bacteria with antibiotic resistance and the antibiotic is no longer effective.

Ideally, oral antibiotics should be taken on an empty stomach so that stomach acid does not interfere with absorption.  Several antibiotics, for example amoxicillin, have been developed so that stomach acid has no effect on their absorption.  Other antibiotics, most notably erythromycin, cause stomach irritation.  Taking erythromycin with food avoids unwanted side effects and increases your compliance.  Some foods specifically interfere with antibiotic absorption, for example milk inhibits tetracycline’s absorption.  All antibiotics should be taken with an 8 ounce glass of water.  The water helps the tablet dissolve and be absorbed.

Antibiotics are usually taken throughout the day, and the spacing of the doses should be equal.  Four times daily dosing means about every six hours and twice daily dosing means every 12 hours.  Setting specific times during the day may help you remember to take your antibiotics, but make sure the times are convenient for you.

If you are unsure of when or how to take an antibiotic, ask your pharmacist.  Remember to finish the complete course of antibiotic therapy.  If you stop too soon, you may feel better, but 100% of the bacteria may not have been eradicated, meaning that you could become ill again and be promoting bacterial resistance to antibiotics.