Doxycycline for Leptospirosis Post-Exposure Prophylaxis
August 8, 2012
In light of the flood brought by the Hanging Habagat yesterday, August 7, many posters are circulating online informing readers on what to do as prophylaxis after supposed exposure to leptospirosis. [EDIT: Sample poster was requested to be removed.]
Leptospirosis is a bacterial infection that affects humans and animals. The infection is commonly transmitted to humans by allowing water that has been contaminated by animal urine to come in contact with unhealed breaks in the skin, the eyes, or with the mucous membranes.
For adult humans at risk from leptospirosis the standard prophylaxis is a single 200mg oral dose of an antibiotic called doxycycline. It provides protection for about a week, so in some cases (such as natural disasters) one tablet is issued per week, for as long as necessary. However it is not a good idea to use antibiotics like this for more than a few weeks at a time, as there are significant risks of creating resistance.
Issues with Children, Pregnant, and Breastfeeding Women
Doxycycline is contraindicated in children, pregnant, and breastfeeding women.
Children under 8 are usually not allowed to take doxycycline due to the potential for side effects, such as the permanent staining of their unerupted teeth, and so in cases where young patients must receive prophylaxis we often give a short course of penicillin instead. It’s not as simple to administer as a single tablet, but just as effective.
Leptospirosis in human mothers is an extremely dangerous condition for both the mother and her fetus – there is a risk in all trimesters of pregnancy and also a potential issue for breastfeeding mothers.
The first thing to say is that the fetus can be infected across the placenta, as the bacteria are small enough to pass the barrier. This ‘transplacental’ infection means that the fetus can become ill independent of the mother – who may have symptoms so mild she doesn’t notice any illness herself. The outcome for the fetus is difficult to predict, and severe illness in the mother is not always a bad prognosis for the fetus. Conversely, the fetus can be critically ill without the mother being aware of any symptoms.
Here is also an announcement from Hon. Marilyn Tiu, Chairman of the Board of Pharmacy:
Dear Partners in the Community Pharmacy Industry,
Many concerned pharmacists are worried about posters similar to the attached. Doxyclycline is a prescription medicine. It should not be given to pregnant women and children. It has many adverse effects and interactions.
We want to stop irrational use of medicines and reduce the risk of antimicrobial resistance. Please make sure to ask for prescription when dispensing doxycycline and antimicrobials. Thank you.
For DSAP and other community pharmacists, pls pass on to other pharmacists. Thank you.
Please spread the information to all pharmacists, especially those in the community. Thank you!