Doxycycline is the most commonly reported tetracycline analogue that causes oesophagitis. More than 70 drugs have been reported in the literature to induce oesophageal disorders, however antibacterials such as doxycycline, tetracycline and clindamycin account for more than 50% of cases1.
Mechanism of action
Patients who have difficulty in swallowing solid dosage forms of medications are more susceptible to doxycycline-induced oesophagitis. When the doxycyline tablet/capsule transits down the oesophageal lumen, it dissolves to form an acidic solution. High local concentrations of the acidic solution resulting from increased transit time or when the drug gets lodged in the oesophagus can cause mucosal lesions. In addition, reflux of the medication which can occur when a patient lies down soon after taking the drug can also cause similar problems. Symptoms of reflux oesophagitis include heartburn, retrosternal pain and regurgitation.
Doxycycline-induced oesophagitis is often self-limiting upon discontinuation of the drug. However, in severe cases, symptomatic treatment may be required.
Overseas reports
The WHO ADR database (which captures the spontaneous ADR reports from more than 60 countries participating in the WHO International Drug Monitoring Program) has 352 suspected reports of doxycycline induced oesophagitis for the period 1969 to 2003. The New Zealand Pharmacovigilance Centre has received 46 suspected reports of oesophagitis associated with doxycycline for the period up to October 2003 and the Australia Therapeutic Goods Administration (TGA) received 46 suspected reports of oesophagitis and 49 suspected reports of oesophageal ulceration associated with this drug2.
Local ADR reports
To-date, the Pharmacovigilance Unit, HSA has received four local reports of retrosternal pain suspected to be associated with the intake of oral doxycycline. In all 4 cases, there was no indication that the adverse reaction progressed to oesophageal ulceration. These cases involved patients between 20 to 24 years of age, who took the antibacterial agent for acne vulgaris or upper respiratory tract infection from two days to 3.5 months. The ADRs were not considered serious in nature by the reporting doctors.
Advice to patients
To minimise this risk, patients should be advised to take doxycycline in an upright position, with food or with a large glass of water and to also avoid taking it just before bedtime.
References
- Jaspersen D. Drug-induced oesophageal disorders: pathogenesis, incidence, prevention and management. Drug Saf. 2000 Mar; 22(3): 237-49.
- Medical Editorial Team. Oesophagitis with doxycycline and others. Prescriber Update 2003;
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