“Patients may have to be prescribed higher doses of antibiotics because of rising rates of obesity,” BBC News has reported. The story is based on a narrative review
“Patients may have to be prescribed higher doses of antibiotics because of rising rates of obesity,” BBC News has reported.
The story is based on a narrative review in The Lancet. The authors say that drugs for treating infection should be prescribed according to body weight (as is the case when prescribing for children). They state that this may turn out to be advantageous to the person taking the drugs, the healthcare provider and the fight against disease in general.
Microbes that are resistant to antibiotics, antivirals or antifungals are a genuine concern. If dosing that is tailored for individuals helps to prevent resistance, then it should be considered. However, changes to current prescribing would be costly and complex. More research is now needed, investigating if the benefits of tailored dosing are enough to warrant a change to current practice.
Dr Matthew Falagas and Drosos Karageorgopoulos of the Alfa Institute of Biomedical Science, Athens, Greece, carried out this research. There was no funding provided for this narrative review. The study was published in the peer-reviewed medical journal_ The Lancet._
This narrative review was accurately reflected in the news reports.
This narrative review presents the authors’ views and experiences about how adult body weight may need to be taken into consideration when prescribing antimicrobials. It should not, therefore, be interpreted as a systematic review or original research. Whether or not tailored dosing for overweight and obese adults reduces the time it takes to clear infection will need further research and follow-up in a variety of adult populations.
The authors describe how advances in molecular biology and pharmacology have enabled the development of drug treatments that are tailored for individual patients. However, although the patient's body size needs to be taken into account for drug treatments to be of most benefit, they say that most dosing regimens, across medical specialties, do not currently take this into consideration.
The authors say that body size varies substantially around the world. The ‘modern epidemic’ of obesity, affecting more than 30% of people in the US and 20% of people in several European countries, needs to be taken into account.
The authors say that, although pharmacokinetic studies (studies of how drugs are distributed, processed and disposed by the body) consider different ages and diseases, body size and other characteristics also need to be taken into account:
The researchers suggest that all available published or unpublished pharmacokinetic data should be reassessed with the aim of identifying the most appropriate dosage adjustments for adults depending on their body weight. Further clinical trials would be needed to confirm that these readjusted doses are safe and effective for use.
This is a valuable discussion, which raises several important issues in the use of drugs to treat infection. The headlines should not be interpreted to mean that obese people are putting extra demand on antimicrobial supplies. The issue is that a dose tailored to body weight may be advantageous to the person, the healthcare provider and the fight against disease in general. The development of microbes that are resistant to antibiotics, antivirals or antifungals is a genuine concern. If individual patient-dosing would help to prevent this resistance, then these suggestions should be considered.
Another important issue is the minimisation of side effects. Clearance of infection is obviously an important outcome for the person taking the drugs, but just as important is avoiding any adverse effects or depleting levels of normal bacteria that live in the body, which can, in itself, lead to other infections. This risk can be reduced by not exposing patients to unnecessary drugs, and by ensuring that if antimicrobials are needed, they are not given for prolonged periods of time or in consecutive courses.
The researchers suggest that dosage adjustments according to body size and body composition should become “an integral part of the process of new antimicrobial drug development”, and this appears to be a worthy argument. However, as they have discussed, it may not be as easy as making one simple adjustment for body weight, and different methods may be needed for different drugs. In addition, changes to current prescribing would have considerable cost and practice implications that need to be considered.
A review of previous study data, as well as new clinical trials that dose according to body weight and that follow-up effects would be needed to see if the benefits are substantial enough to warrant a change to current practice for all prescribed drugs.