Ceftazidime is a third-generation, semisynthetic cephalosporin antibiotic. Cephalosporins are derivatives of 7-aminocephalosporic acid and are closely related to penicillins in structure. Cephalosporins have a six membered sulfur containing ring adjoining a β lactam ring. Ceftazidime is a broad spectrum, β lactam antibiotic, effective against gram positive and gram negative bacteria. Antibiotics require constant drug level in body for therapeutic effect. Ceftazidime is used in the treatment of biliary tract infection. This is achieved by taking the medication at regular interval of time throughout the day and night as prescribed. Ceftazidime is important to take the drug for the full time period as prescribed. If you discontinue the therapy, it may result in ineffective treatment.