Antibiotic resistance: An Introduction

source: Emro

Antibiotic resistance is an increasingly serious patient safety and public health problem worldwide. In Nigeria, the major causes of morbidity and mortality are communicable diseases, and these are generally managed using antimicrobial drugs whose usefulness is being threatened by antimicrobial resistance. Antibiotic resistance is commonly observed with irrational use of antibiotics for gastrointestinal infections (like enteric fever) _usually associated with diarrhoea; urinary tract infections and sexually transmitted infections…

Meanwhile, antibacterial agents that are commonly misused include tetracycline, septrin /co-trimoxazole, flagyl/ metronidazole, erythromycin, ciprofloxacin, penicillins (amoxil, ampicillin), and cephalosporins (cefixime, cefuroxime).

Since their discovery, antibiotics have contributed to the reduction in mortality and morbidity from infectious disease and have made other treatments and procedures such as cancer treatments and organ transplantation possible. However, the lingering issue of antibiotic resistance leaves a question on the lips of many: will the antibiotic era last forever…?

Now, most bacteria that cause serious infections and could once be successfully treated with several different antibiotic classes, have now acquired resistance—often to many antibiotics. Resistance genes are often recycled from humans to animals and the environment (soil, water supply, air). This encourages spread of resistance between and across populations. Prolonged dosing of cattle with antibiotics (to enhance growth) can select resistant strains to antibiotics, which otherwise would have been effective in treating infections in humans who incidentally feed on these livestock.

Sore throat, common cold, acute otitis media, acute infective conjunctivitis, acute bronchitis and acute sinusitis are the most common infections presenting in primary care. Clinical experience suggests that antibiotics use in these conditions has limited value, and can lead instead to adverse effects, increased consultations, high cost and an increased risk of resistance. Therefore, nonlethal and self-limiting conditions require over-the-counter cough and cold medicines (including analgesics) for resolving symptoms, and NOT antibiotics.

The more often the patient has a course of antibiotics the more opportunity that patient’s bacteria have to develop multiple or ongoing resistance. For example, the prolonged use of broad spectrum antibiotic like doxycycline for treating bacteria-provoked acne can lead to rapid development of resistance coupled with adverse effects like allergies, diarrhoea, and superinfection with fungi and harmful bacteria. Therefore, taking antibiotics for more than 10 days is not advisable unless the benefits outweigh risk. Interestingly, there is a phenomenon called cross-resistance. Here resistance emerges for the culprit drug (doxycycline) as well as other drugs in the same class (tetracycline). 

Key messages 

  • Indeed, antibiotics and other antimicrobial agents are a lifeline to billions of people, particularly in resource-limited countries where bacterial infections are predominant. Their benefits are being threatened by the self-medication, people’s lack of knowledge and inappropriate use of antibiotics, especially in developing countries like Nigeria.
  • Note that antimicrobial resistance encompasses antibiotics or antibacterial agents, antiprotozoal agents (e.g. antimalarial agents), antifungal agents, antiviral agents among others.
  • Antimicrobial resistance is harmful to health because it reduces the effectiveness of antimicrobial therapy and tends to increase the severity, incidence and costs of infection.


  • Pharmacists are well placed to advise patients about antibiotics, particularly to take them at regular intervals and finish the course. It is also important to provide advice about side effects and interactions between antibiotics and food, and antibiotics and other medicines.
  • The resistance of bacterial populations to antimicrobial agents is constantly changing and can become a serious clinical problem, rendering previously useful drugs inactive
  •  Its vital to realise antibiotics address infections not symptoms, hence antibiotic would not stop the cough directly but would terminate any causative bacteria if it is susceptible (or sensitive) to it.
  • Antibiotics don’t work on viruses. Most cough and cold symptoms are caused by viruses.
  • Antibiotic misuse, either by patients or healthcare professionals, is one of the major contributing factors to antimicrobial resistance; antibiotic resistance is the main cause of treatment failure…


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