The rare serious side effects of antibiotic abuse

A 17-year-old patient with a free history came in due to febrile (up to 39⁰C) with a cough lasting about a week. The patient had been examined 3 days ago by a physician who recommended symptomatic treatment for possible viral infection. The patient reported no other respiratory symptoms (runny nose, nasal congestion, pharyngitis) but complained of severe weakness and easy fatigue. On clinical examination, he presented with mild right lung acroasthenia, but his blood oxygen was low (SO2 89-90% in air) and he was taking around 30 breaths per minute (normally 12-14), but without shortness of breath in the sitting or lying down position. Due to his condition, admission to hospital was recommended. There he was diagnosed with bilateral pneumonia, given oxygen and intravenous antibiotics (quinolone) and after 10 days of hospitalization the patient was discharged from the hospital in almost perfect condition. Despite extensive diagnostic testing the cause of the pneumonia was not found.

Two weeks later, and while he was well at 2 visits in between, the patient again developed decidious febrile movement (as high as 37.7⁰C) and cough, this time with pharyngitis and catarrh. He did not complain of weakness or easy fatigue and on examination there was redness of the throat, with no findings from the tonsils, and mild lymphadenopathy in the neck. Lung auscultation was without findings and blood oxygenation was normal (SO2 98%, 13 breaths/min). The rest of the examination was without findings and the overall condition of the patient was very good. The picture resembled a viral respiratory infection and conservative treatment was recommended. His mother's concern due to the previous history led to the performance of strep test and blood tests, which were all negative (normal number and type white blood cells, slightly increased CRP). Despite the mother's insistence on antibiotics, symptomatic treatment and monitoring for the next 4 days was again recommended.

The patient's symptoms remained unchanged after 2 days and the mother's concern, despite re-communication, led to the call of another doctor, who gave in to her pressure and administered antibiotic treatment (2nd generation cephalosporin). As expected, the symptoms subsided 2 days later and the patient felt well until 2 days before the end of treatment, when diarrhoea appeared, gradually worsening. Antibiotics were discontinued, symptomatic treatment with probiotics for possible antibiotic-induced diarrhoea and diet modification was administered but the diarrhoea did not subside. On day 5 of the diarrhea the patient re-emerged with fever, this time with abdominal pain. The mother, worried, contacted me again and told me that it was preceded.

On examination, the patient was dehydrated, severely distressed, with fever (38.5 ⁰C) and diffuse tenderness in the abdomen, mainly along the colon with mild reduction in its motility. The patient was re-admitted to the hospital where he was diagnosed pseudomembranous colitis. The patient received a new antibiotic treatment with vancomycin and metronidazole, his symptoms gradually subsided and he was discharged after 15 days of hospitalisation. Three months later, he had no further episode of diarrhea, febrile or abdominal pain.

Pseudomembranous colitis is a relatively rare complication of infection by an anaerobic microbe called Clostridium difficile. Its incidence is constantly increasing, as epidemics that have occurred in North America and North Africa have been reported. The increasing incidence of epidemics in B.C. and Europe in the past decade has led to more frequent use of algorithms for early diagnosis. Infection by the Clostridium difficile occurs mostly after antibiotic use (type, number, duration of treatment, repeated use), hospitalisation in hospitals or elderly and rehabilitation centres, chemotherapy in elderly patients and in pregnant women. The occurrence in young people is less frequent. Although previously thought to be an in-hospital infection, more recent studies show that the incidence in hospital and community settings is similar. Some antibiotics are more implicated (quinolones, cephalosporins, carbapenems, clindamycin) than others (penicillins, macrolides, tetracyclines), but all antibiotics (even those used to treat the infection) have been associated with its occurrence.

Its main feature is the high treatment failure rates (~14-22%) and frequent relapses (~24-27%). In fact, the probability of a second relapse after the first one has resolved is strikingly high (~40-50%), further increasing the risk of further relapses. These result in a deterioration of patients' quality of life, frequent hospitalisations and increased treatment costs. During epidemics, mortality rates reached 7%.

Sources 

www.pubmed.com

www.medscape.com

Vardakas KZ et al. Clostridium difficile infection following systemic antibiotic administration in randomised controlled trials: a systematic review and meta-analysis. Int J Antimicrob Agents. 2016;48(1):1-10.

Vardakas KZ et al. Treatment failure and recurrence of Clostridium difficile infection following treatment with vancomycin or metronidazole: a systematic review of the evidence. Int J Antimicrob Agents. 2012;40(1):1-8.