Utilization of restricted antibiotics in a university hospital in Thailand.

Antibiotic resistance, a major negative consequence of antibiotic overuse, is an important problem worldwide. Various means have been used to control antibiotic usage including the use of an antibiotic order form (AOF), restricted antibiotic formularies and provision of educational information. The present study was designed to evaluate the use of antimicrobials in a 1,000-bed university hospital. Antimicrobial agents, likely to be abused namely ceftazidime, cefepime, cefoperazone/sulbactam, imipenem/cilastatin, meropenem, ciprofloxacin, netilmicin, vancomycin, azithromycin and clarithromycin, were selected for evaluation. A simple AOF with educational information was used as a mean to follow up the treatment. The investigator collected data from the filled AOF and the patient's charts of the Department of Internal Medicine from June to November 2000; all relevant data were assessed. The appropriateness of antibiotic use, assessed according to the criteria specified in the AOF, showed that 74% of these antibiotics were prescribed appropriately; this may prove the effectiveness of the system used in the present study. However, 348 of the 430 prescriptions (80.9%) were prescribed empirically at the initial stage for treatment of nosocomial infections in patients with serious conditions like pneumonia, sepsis and febrile neutropenia. Drugs that were frequently used empirically were ceftazidime (37.9%), imipenem/cilastatin or meropenem (19.3%), and cefoperazone/sulbactam (12.1%) respectively. Ceftazidime and imipenem/cilastatin or meropenem were also frequently used inappropriately among 111 prescriptions that were classified as an inappropriate prescribing. The most common misuses were prescriptions of the drug that did not follow the specified indications (70 prescriptions), no dosage adjustment in patients with renal impairment (39 prescriptions), improper dose (12 prescriptions) and improper dosing interval (9 prescriptions). The results suggested overuse of certain antibiotics remain to be an unsolved problem. Better monitoring and strict controlled use of the problematic antibiotics, ie ceftazidime, imipenem/cilastatin or meropenem and vancomycin are essential to promote rational drug use as well as to reduce the frequency of drug resistance.

Dissolution profile of four brands metoprolol tablet available in Thailand.

Metoprolol, a cardio selective -blocker, is one of the most widely used drugs in the management of cardiovascular disorders. Various generic metoprolol tablets are available and the prices are vary tremendously. Since the dissolution rate is the rate-limiting step of drug absorption it is essential to have the dissolution data in hand for selection of the drug according to the cost. The present investigation chose the three most often prescribed brands of metoprolol tablets (100 mg) and subjected them to pharmaceutical testing, namely, the uniformity of the tablet, hardness, disintegration rate, and dissolution rate. The results indicate the good quality of the locally-produced brands tested; are of good qualities however, dissolution rate of “drug C” was slower than other brands.

Bioavailability of two brands carbamazepine tablets.

Bioavailability of carbamazepine (CBZ) tablet in Thai subject has never been reported before. Owing to the big difference of the drug cost and the National Drug Policy to promote the use of generic drugs, it is therefore essential to compare the bioavailability of tablets available in Thai market. Two brands of CBZ tablets that are commonly used in various hospitals were included in the present study in 17 healthy Thai volunteers. The drugs were given in randomized crossover fashion. Vanes blood samples were grown at 0,1,2,3,4,6,8,10,24,4,8,72,96,120, and 144 hours prior to and after ingestion of 2x 200 mg CBZ tablets A washout period of 4 weeks was allowed because of its autoinduction of hepatic enzymes. Plasma samples were separated and the amount of CBZ contained in each samples were analyzed by HPLC. The present results indicate a significantly slower rate of absorption of drug A nut the extent of absorption appears to be equal to that of drug B.

Dissolution profile of three brands carbamazepine tablets.

Three brands of carbamazepine tablets available in Thailand were assessed for their pharmaceutical properties according to the requirement of pharmacopoeia. The present study demonstrated that the dissolution profile of CBZ tablets varied markedly to the hardness of the tablet. All brands of CBZ tablet tested fulfill most of the pharmacopoeial requirements, (e.g. weight variation, content uniformity, disintegration tie, etc.), except the dissolution and the friability limit. The present results indicate the problem of dissolution of CBZ tablet. However, Thai FDA has not yet required the dissolution limit for CBZ tablet. The present study, therefore, provide the evidence for addition of CBZ tablet to the list of drugs that are subjected to the dissolution testing.