By Dr Jacqueline E Campbell

Antibiotics can kill bacteria.

THE development of antibiotics has been one of the great discoveries of modern medicine.

Antibiotics can kill bacteria. They can relieve symptoms of bacterial infections and help to speed up the recovery process. Antibiotics can cure life-threatening infectious diseases and save lives.

However, antibiotics are overused. This has caused many different types of bacteria to become resistant (unresponsive) to it. Consequently, many diseases cannot be treated as well as they could have been treated in the past.

Sometime ago, a patient “told me off” in no uncertain terms when I denied her request to be treated with antibiotics for a common cold. I stood my ground. It is noteworthy that she called me two days later to inform me that she had recovered without taking any antibiotics.

Hers was not an unusual demand. Individuals often expect antibiotics to be prescribed to treat medical conditions for which antibiotics are not suitable. Additionally, people self-prescribe and will visit the doctor after obtaining antibiotics on their own advice.

Antibiotics only work against bacteria. Many infections (for example coughs, stuffy nostrils, bronchitis, and influenza) are caused by viruses and cannot be treated using antibiotics.

Antibiotic resistance

Antibiotics are among the most commonly prescribed drugs used in human medicine. However, up to 50 per cent of all the antibiotics prescribed for people are not needed or are not effective as prescribed. Antibiotics are commonly utilised in the treatment of food animals to prevent, control and treat disease, and to promote the growth of the animals.

Antibiotic resistance refers to the ability of bacteria to resist the effects of drugs — that is, the bacteria are not killed and so they continue to multiply.

The increasing and, at times, improper use of antibiotics has contributed to the development of antibiotic resistance. This has led to the evolution of many bacterial strains that no longer respond to treatment with common antibiotics.

In recent years, we have observed the evolution of the following:

1) Antibiotic resistant strains of Staphylococcus aureus (methicillin resistant Staph aureus or MRSA). Staphylococcus aureus is a bacteria commonly found in the body; it can usually be treated with antibiotics. However, over the years some strains of Staphylococcus aureus have become resistant to antibiotics that once destroyed them.

2) Vancomycin resistant Enterococci (VRE), which can cause intestinal illness in people taking antibiotics for other conditions.

3) Gonorrhoea, a sexually transmitted disease, has progressively developed resistance to the antibiotic drugs prescribed to treat it.

While some people are at greater risk than others, no one can completely avoid the risk of antibiotic-resistant infections. Infections with resistant organisms are difficult to treat, requiring costly and sometimes toxic alternatives.

Bacteria will inevitably find ways of resisting antibiotics. This is the reason why forceful action is needed to prevent the resistance that already exists from spreading, and to keep new resistance from developing.

The following are important facts to know about taking antibiotics

1. Be cautious when taking antibiotics as this can help prevent antibiotic resistance.
2. Never assume that an antibiotic prescribed for someone else will be effective for you. Doctors choose antibiotics based upon the patient’s individual medical history and the type of bacteria likely to be causing the infection. Sharing prescription medications is a not a good and safe practice.
3. Never “save up” antibiotics for later use. A person needing an antibiotic should be evaluated by a physician each time an antibiotic is needed.
4. Never stop taking prescribed antibiotics because you feel better. Antibiotics should be taken for as long as the doctor has prescribed them. These drugs work fairly rapidly, and so you may feel much better after taking only a few days’ worth of a prescribed course of antibiotics. However, this does not indicate that all the bacteria have been killed. The remaining bacteria may cause the illness to recur. Taking the full prescribed course of antibiotics ensures eradication of the offending bacteria.
5. Antibiotics can cause a number of adverse effects, including nausea, vomiting and diarrhoea. Some women develop vaginal yeast infections while taking certain types of antibiotics. This happens because the antibiotic kills naturally occurring bacteria that protect the body from yeast infection, leading to the development of yeast infections while the antibiotics are taken.
6. If your doctor directs you to stop taking an antibiotic or switch to a different antibiotic, return any unused medications to the pharmacist for disposal or ask your pharmacist for proper ways to dispose of the medications.
7. Ask your doctor or pharmacist whether the antibiotic should be taken before, with or after a meal and whether you should avoid alcohol or direct sunlight while taking the drug.
8. If you are supposed to take your antibiotic three times each day, the drug needs to be taken at set times so that the effect is spread out evenly over the course of the day. For example, a drug that needs to be taken every eight hours could be taken at 6:00 am, 2:00 pm and 10:00 pm.
9. Antibiotics can interact with other medications, including blood thinners, antacids and oral contraceptives. It is important to inform your doctor and pharmacist if you take other medications.

If you have questions, ask your doctor or pharmacist.

(Dr Jacqueline E Campbell is a family physician, university lecturer and pharmacologist. She is the author of the book A patient’s guide to the treatment of diabetes mellitus.)