What is doxycycline?
Doxycycline is an antibiotic that is widely used to treat a range of infections. It is also an anti-malarial medication and the ADF’s first choice for malaria prophylaxis (prevention) in deploying personnel.
Is doxycycline safe?
In registering doxycycline for use in Australia, the Therapeutic Goods Administration (TGA) assessed that it was safe and effective. All medications have side effects and not everyone is able to tolerate certain drugs, even those registered by the TGA and commonly used across Australia. In particular, doxycycline is not suitable for pregnant women or young children as it may cause problems in developing teeth.
What are the side effects of doxycycline?
The most common side effects of doxycycline are gastrointestinal upset – mainly heartburn, nausea and vomiting. These can be reduced by taking doxycycline with food and avoiding lying down straight after taking it.
Doxycycline can also cause photosensitivity (increased risk of sunburn). This can be reduced by using a high sun protection factor sunscreen and other protective measures.
Less commonly, doxycycline has been known to cause gut inflammation (colitis), peeling skin conditions, muscle and joint pain, headache and confusion, ringing in the ears, psychiatric symptoms (depression, anxiety) and liver problems.
How long can doxycycline be taken for?
For malarial prophylaxis, doxycycline is taken for the duration of the deployment, and for an additional two weeks afterwards. For deployments longer than six months, doxycycline may be replaced by atovaquone/proguanil for alternating three-month periods.
While the manufacturer recommends daily doses of doxycycline be taken for a maximum of eight weeks, the British National Formulary and international studies suggest doxycycline may be taken safely for up to two years. Clinical experience of using closely related antibiotics (minocycline and tetracycline) for acne treatment suggests that doxycycline can safely be taken for periods of up to 12 months. International anti-malarial guidelines also advise that doxycycline can be take safely for long periods.
Can doxycycline interact with other medications?
Like most medicines, doxycycline can interact with several other medications. In particular, it may interact with the oral contraceptive pill and make it less effective. Anyone prescribed doxycycline should inform their doctor about what else they are taking, including over the counter medications.