From the Philippine Leptospirosis Clinical Practice Guidelines 2010:
The use of chemoprophylaxis REQUIRES PRIOR CONSULT WITH
A PHYSICIAN. It should not be taken unless prescribed and fully explained
by a physician, including common side-effects and contraindications. SINCE
ANTIBIOTIC PROPHYLAXIS IS NOT 100% EFFECTIVE, INDIVIDUALS SHOULD
CONTINUE TO MONITOR THEMSELVES FOR FEVER AND OTHER FLU-LIKE
SYMPTOMS and should continue to wear personal protective measures.
Post exposure prophylaxis for leptospirosis:
1) For single exposure to flood water, WITHOUT wounds &/or cuts on skin-
Doxycycline 100mg/capsule, 2 caps (200mg) single dose within 24-72h post exposure
2) For single exposure to flood water WITH wounds &/or cuts on skin OR accidental ingestion of contaminated water-
Doxycycline 100mg/cap, 2 caps (200 mg) once daily x 3-5 days within 24-72h post exposure
3) For continuous exposure to flood water WITH or WITHOUT wounds
Doxycycline 100mg/cap, 2 caps (200 mg) once weekly until the end of exposure
Doxycycline should not be taken by (is contraindicated in) children, pregnant and breastfeeding women or those with known allergies to Doxy-, Tetra- and Minocycline. Doxycycline should be taken with food or after meals.