NH: Is there a limit on how many times a year that a person can be safely prescribed antibiotics for his/her ailment?
Dr Sujana: We seem to have started with a complex question which unfortunately has no straightforward answer! If enquiring whether there is a measurable point beyond which antibiotic exposure in a year can lead to adverse events including antibiotic resistant bacteria, then there isn’t any limit that can be considered as ‘safe’ .

It is important to note that we all have a multitude of bacteria naturally residing in our bodies, especially in our gut. These ‘good bacteria’ help maintain our bodies’ important functions, such as digesting the food we consume. When you are prescribed a certain antibiotic, it will kill the infecting bacteria it targets, but will also to an extent kill off part of the ‘good bacteria’ population in the same environment. When this occurs, other bacteria which are resistant to that antibiotic can be selected out, that is, increase in number to replace the bacteria which have been killed off. This effect will not be as significant if the antibiotic used is narrow spectrum, meaning that it is specific for that particular infecting bacteria and is used for an appropriate time period.

Problems can arise when the antibiotic used is broad spectrum, meaning that it will eradicate a much wider range of bacteria, leading to greater damage to the residual ‘bacteria ecosystem’ and thus increasing the risk of selecting out more resistant bacteria strains. A similar effect will occur if the antibiotic is given for a longer rather than shorter duration, especially if this exceeds the correct duration of treatment.

Many healthy people are already carrying these resistant strains in their bodies without knowing it, as simply harbouring these resistant bacteria does not automatically make you sick.

However should such people fall ill or undergo surgery, their body defence systems could be affected, putting them at risk of developing a resistant bacterial infection.

Thus any antibiotic exposure, warranted or not, will change the ‘bacteria ecosystem’ in your body. If you are taking a course of antibiotics for a valid reason, for example an urinary tract infection and you recover from that infection, then the benefit of taking that course outweighs the small risk of increasing the resistant bacteria in your body. Conversely if you take a course of antibiotics when it was not necessary, for example a viral respiratory infection or if the course was not prescribed by a registered doctor, you would have put yourself at risk of developing these resistant bacteria without any corresponding benefit to yourself.

NH: We are often asked to finish a course of antibiotics prescribed to us. What are the ramifications of not completing a course of antibiotics?
Dr Sujana: When your doctor prescribes a course of antibiotics to you, it is because based on clinical evaluation, you have a physical ailment due to a particular bacterial infection. The duration of the course can vary between a few days and a couple of weeks, but the actual period would depend on that bacteria and the type of infection it causes.

Concerns arise when the patient fails to complete the course, such as stopping a 7 day course after only 3 to 4 days. This may happen because they find it difficult to follow the dosing schedule or worse still, they stop taking the antibiotics prematurely because they feel better, and may decide to save the balance of their pills ‘for next time just in case’! In both instances this would increase the risk of developing resistance and hence treatment failure in the future.

NH: How will we know if we need antibiotics when we’re sick?
Dr Sujana: The simple answer is that you will not know by yourself! The vast majority of infections that a person will experience in the community such as the common cold, flu, sore throat or bronchitis are caused by viruses and thus do not require antibiotics. You will need to be examined by your doctor, who will then decide if antibiotic therapy is required for your ailment.

In addition, some symptoms commonly associated with infections, such as fever or cough, may be due to other causes. A persistent fever could be due to conditions causing an inflammatory state in the body such as connective tissue disease or cancer, while a chronic cough may be due to structural lung disease like asthma or fibrosis. If in doubt, always consult your doctor.

NH: How do antibiotics work in the body?
Dr Sujana: Antibiotics work by targeting the bacteria causing infection in the body by different methods. They can attach themselves to the outer surface of the bacteria or enter directly into the bacteria, which will either kill the bacteria or control it by blocking its reproduction. By these methods, the infection will be successfully treated if the correct antibiotic is prescribed for the appropriate period of time and is taken as directed by the patient.

Problems can arise when the patient does not take the antibiotic following the dosing instructions, or if he/she stops taking it altogether without informing the doctor. The bacteria is thus exposed to the antibiotic without being killed or controlled, which will give it the opportunity to develop resistance to this antibiotic, which can cause failure of treatment in the future if the same antibiotic is used again.

NH: Are there any known risks linked to the use of antibiotics?
Dr Sujana: Like all prescribed medications, antibiotics can cause side effects in patients using them. For the most part these are minor and tolerable, such as nausea, stomach discomfort and diarrhoea and will resolve once the antibiotic course is completed. A small proportion of patients may find that these effects persist, which would make it difficult for them to complete the course. These patients should reconsult the same doctor who initially treated them (as far as possible) so that an alternative and better tolerated antibiotic can be substituted. Even less commonly, a patient may develop an allergic reaction to the antibiotic (which in rare cases can become life threatening) or complications such as hearing loss, kidney damage or liver inflammation. These uncommon complications can still be reversible if the patient seeks early medical attention.

NH: Is there any group of people who should not be prescribed with antibiotics?
Dr Sujana: Antibiotics are generally prescribed for bacterial infections which if left untreated, could be life threatening or fatal in some cases. As such infections can potentially affect everyone in the community, anyone in the community who develops such an infection should be treated. However it must be noted that in certain patient groups, such as pregnant women or those with chronic kidney disease, the choice of antibiotics will be limited, as the normal 1st choice antibiotic may cause more harm than benefit. In these patients, either a safer alternative would be used (if pregnant) or the antibiotic dosage would be adjusted (if kidney disease).

Patients who are already aware that they are allergic to a particular antibiotic or any other type of medication should always inform their doctor before any new antibiotic is prescribed. Patients who are already taking medications for other conditions like diabetes or heart disease should likewise inform their doctor about this, in order to minimise the chance of new adverse effects caused by the newly prescribed antibiotic interacting with their original medications. Women who are pregnant or who suspect they could be pregnant should also share this information with their doctor in advance.

It is important to highlight that antibiotics, when used correctly, are potentially life saving or limb saving medications. One should not hesitate to use them if they are prescribed for a specific bacterial infection that needs treatment.

NH: What is antibiotic resistance and why should we be more aware about it?
Dr Sujana: Antibiotic resistance refers to the partial or total failure of an antibiotic to kill or control the bacteria against which it was originally prescribed. This occurs due to the survival mechanisms that bacteria develops in order to protect themselves from the action of antibiotics. These survival mechanisms are more likely to be triggered if the antibiotic use was inappropriate, as was noted in question 1. As a result an antibiotic which could previously successfully treat a bacterial infection will now fail if the bacteria causing this infection has developed resistance, as mentioned earlier.

This is causing serious concern worldwide for several reasons. If the commonly used 1st choice antibiotics no longer work due to resistance, stronger antibiotics would be needed, which generally need to be given in hospital and for longer periods, resulting in increased healthcare costs and a higher rate of more serious adverse effects. Mortality rates would also be higher in such patients, and there would also be an increased risk of spread of these resistant bacteria in the community and hospitals. The situation will only become worse as development of new antibiotics is an extremely slow and expensive process and cannot keep up with the rate of new bacterial resistance, if antibiotics continue to be misused.

NH: How do bacteria become resistant to antibiotics?
Dr Sujana: Antibiotic resistance occurs naturally and is selected out when surrounding friendly bacteria are killed, which can occur with any antibiotic. As I mentioned earlier but is important to reemphasise, if the antibiotic is appropriate then this effect will be minimal; magnification of this effect occurs if too ‘broad spectrum’ antibiotics are used which will kill off far too many friendly bacteria (which would be replaced by the resistant bacteria instead) or if the appropriate antibiotic is taken for a shortened or prolonged course rather than following the correct treatment duration.

NH: Is there anything a person can do to help prevent the spread of antibiotic resistance?
Dr Sujana: The public have an important role to play in helping to prevent the spread of antibiotic resistance, since most infections would be managed in the community at either government or private health clinics

Never pressure your doctor into prescribing you antibiotics for your current ailment, even if you may have received antibiotics for similar complaints in the past. Your doctor would have to reassess your condition and make a decision based on clinical judgment.

If you are prescribed antibiotics, always complete the full course following the dosing instructions. In the event you experience side effects and are unable to, or uncertain if you should complete the course, consult your doctor again as early as possible.

Never share your prescribed antibiotics with any other person such as your family members or friends even if their ailments appear similar to yours. They should always consult their own doctors instead.

Do not try to buy antibiotics over the counter at pharmacies without a valid prescription from a registered doctor. Attempting to do so would be against Malaysian prescribing laws.

Learn about common infections in the community from your doctor or local healthcare institution. Alternatively, access reliable online sources for further information, such as the websites of the Ministry of Health Malaysia, the Malaysian Pharmaceutical Society or the World Health Organization

Keep up to date with your vaccines as appropriate for your age, as they will prevent certain infections and so lead to less illnesses and potential for antibiotic misuse.

Lastly, remember that prevention is better than cure! Stay home from work or school if you have an infection to prevent spreading it to others. Take appropriate measures such as maintaining a safe distance and proper hand hygiene when visiting someone with an infection that can be spread by close contact or coughing/sneezing. Maintain a healthy lifestyle in terms of your diet, weight and personal habits, as this will also help reduce the risk of developing many infections.

Q & A with Dr Sujana LS Saravanamuttu
Infectious Diseases Physician,
Hospital Kuala Lumpur