Homeâ€ēDrug Dosesâ€ēDoxycycline
💊 Tetracycline antibiotic · Malaria · Rickettsia · Leptospirosis · Acne · India-specific

Doxycycline Dose Calculator

India ¡ Malaria Prophylaxis & Treatment ¡ Leptospirosis ¡ Scrub Typhus ¡ Community Pneumonia ¡ Acne ¡ Doxt-S ¡ Doxybact ¡ Microdox

100mg BD standard doseMalaria: 100mg OD prophylaxisAvoid <8yr & pregnancyTake with full glass water upright

Doxycycline Dose Calculator

Doxycycline Dose
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Tablet
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Duration
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Take with
Plenty of water ¡ sit upright
Sun protection
Phototoxicity — use sunscreen
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💊 Drug profile
ClassTetracycline antibiotic
RoutesOral ¡ IV
Half-life12–25 hours (once or twice daily)
Food effectCan take with food (reduces GI upset)
Avoid withAntacids ¡ Ca ¡ Mg ¡ Al ¡ Fe (2h gap)
PhototoxicitySignificant — avoid sun exposure
đŸˇī¸ Indian brands
Tab 100mgDoxt-S ¡ Doxybact ¡ Microdox ¡ Doxy 1
Cap 100mgDoxycip ¡ Doxt ¡ Winadox
Dispersible 100mgDoxt-S ¡ Doxrid
IV 100mg vialDoxycycline Inj (generic)
đŸĻŸ India-specific uses

đŸĻŸ Malaria prophylaxis (Plasmodium falciparum endemic areas)

🐀 Leptospirosis (post-flood, agricultural workers)

đŸĻŸ Scrub typhus / Orientia (rice fields, North-east India, hills)

🐄 Brucellosis (livestock workers)

💊 Acne — widely used across India

Doxycycline — Clinical Guide India

Doxycycline is a broad-spectrum tetracycline antibiotic with a uniquely important role in India due to the country's high burden of vector-borne and zoonotic diseases — particularly malaria, leptospirosis, scrub typhus, brucellosis, and rickettsial infections — for which it is either first-line or the key oral treatment option. Its long half-life allows once or twice daily dosing, and its excellent intracellular penetration makes it effective against obligate intracellular organisms including Rickettsia, Chlamydia, Mycoplasma, and Coxiella burnetii.

Malaria — prophylaxis for travellers and endemic areas

Doxycycline 100 mg once daily is the preferred chemoprophylaxis for Plasmodium falciparum malaria in chloroquine-resistant areas — which includes virtually all P. falciparum-endemic areas of India, particularly Northeast India, Jharkhand, Odisha, and parts of Chhattisgarh. Start 1–2 days before travel to endemic area and continue for 4 weeks after leaving. As a treatment component, doxycycline 100 mg twice daily for 7 days is used alongside artesunate (or artemether-lumefantrine) for uncomplicated P. falciparum malaria — not as monotherapy. NVBDCP national guidelines endorse artesunate + doxycycline as one of the recommended regimens for P. falciparum in India.

Scrub typhus — the most important febrile illness missed in India

Scrub typhus (Orientia tsutsugamushi, transmitted by larval trombiculid mites) is one of the most underdiagnosed causes of acute febrile illness in India, particularly in rural and hilly areas of Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Northeast India, Tamil Nadu, and Kerala during the post-monsoon season. It causes a febrile illness with headache, myalgia, and characteristically a painless eschar at the mite bite site — though the eschar is missed in up to 40% of Indian cases. Doxycycline 100 mg twice daily for 5–7 days is dramatically effective — fever typically defervesces within 24–48 hours of starting treatment. In children under 8 years, azithromycin is the alternative.

Leptospirosis — the flood-season antibiotic

Leptospirosis (Weil's disease) is endemic in India's coastal, flood-prone, and agricultural regions — particularly during and after the monsoon. Mild leptospirosis: doxycycline 100 mg twice daily for 5–7 days. Post-exposure prophylaxis after high-risk exposure (flood wading, rat contact): doxycycline 200 mg as a single weekly dose. Severe leptospirosis (Weil's disease with jaundice, renal failure, pulmonary haemorrhage): IV penicillin G or IV ceftriaxone — oral doxycycline is not adequate for severe disease.

Oesophageal injury prevention — the critical administration instruction

Doxycycline can cause severe oesophageal ulceration if the tablet dissolves in the oesophagus rather than reaching the stomach. This is one of the most preventable drug complications. Always counsel patients: take doxycycline with a full glass of water (minimum 200ml), remain sitting or standing upright for at least 30 minutes after taking, and never take at bedtime without water. Taking with food or milk is acceptable and reduces GI side effects without significantly reducing absorption.

Frequently Asked Questions

Can doxycycline be given to children under 8 years?+
No. Doxycycline (and all tetracyclines) are contraindicated in children under 8 years due to permanent staining of developing teeth (dental fluorosis-like discolouration) and potential effect on bone growth. The exception is a single-course of treatment for life-threatening infections (e.g. rickettsial disease) when there is no alternative — in which case, clinical benefit outweighs the dental staining risk (a short course causes less staining than prolonged exposure). For scrub typhus and rickettsial disease in children under 8: azithromycin is the preferred alternative.
Why does doxycycline cause photosensitivity and how should patients be counselled?+
Doxycycline accumulates in the skin and causes phototoxicity — a reaction to UV light that resembles severe sunburn, occurring within minutes of sun exposure. This is a direct drug-skin-UV interaction, not an allergy. In India, where sun exposure is high (particularly for outdoor workers and agricultural communities who are also the main patients needing doxycycline for leptospirosis/malaria), phototoxicity is a significant problem. Counsel patients to: apply SPF 30+ sunscreen to all exposed skin daily, wear full-sleeved clothing in the sun, avoid midday sun exposure, and wear a hat. Phototoxicity improves rapidly after stopping doxycycline.
âš ī¸Avoid in children under 8 years, pregnant women, and breastfeeding. Take with full glass of water and remain upright 30 min — risk of oesophageal ulceration. Use sunscreen daily — phototoxicity risk. Verify against BNF, NVBDCP, and current malaria treatment guidelines.

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