Schedule H

Oral, Intravenous

Form Strengths

Capsules 100 mg

Tablets 100 mg

Dispersible tablets 100 mg

Tablets (extended-release) 40 mg (sub-antimicrobial dose for rosacea)

Injection (powder for reconstitution) 100 mg/vial

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

1. Scrub Typhus / Rickettsial Infections

Parameter Recommendation

Starting dose 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily

Maximum dose 200 mg/day

Duration 7 days (extend to 14 days if severe or delayed response)

Clinical notes First-line therapy per ICMR/NCDC guidelines; continue until afebrile for 48–72 hours; highly endemic in Himalayan foothills, NE India, South India

1. Cholera

Parameter Recommendation

Starting dose 300 mg single dose OR 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily if multi-dose regimen

Maximum dose 300 mg/day

Duration Single dose or 3 days

Clinical notes Adjunct to ORS; reduces stool output and vibrio shedding; per NCDC outbreak guidelines

1. Uncomplicated Genital Chlamydia Infection

Parameter Recommendation

Starting dose 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily

Maximum dose 200 mg/day

Duration 7 days

Clinical notes First-line per NACO STI guidelines; treat partner simultaneously; test-of-cure not routinely needed

1. Non-Gonococcal Urethritis / Cervicitis

Parameter Recommendation

Starting dose 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily

Maximum dose 200 mg/day

Duration 7 days

Clinical notes Covers Chlamydia and Mycoplasma genitalium; combine with ceftriaxone if gonorrhoea not excluded

1. Pelvic Inflammatory Disease (PID)

Parameter Recommendation

Starting dose 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily

Maximum dose 200 mg/day

Duration 14 days

Clinical notes Use with ceftriaxone 250 mg IM single dose ± metronidazole 500 mg twice daily; per NACO syndromic management guidelines

1. Leptospirosis (Mild–Moderate)

Parameter Recommendation

Starting dose 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily

Maximum dose 200 mg/day

Duration 7 days

Clinical notes Effective if started within first 4 days of illness; IV penicillin preferred for severe/icteric disease

1. Brucellosis

Parameter Recommendation

Starting dose 100 mg twice daily

Titration Not applicable

Usual maintenance dose 100 mg twice daily

Maximum dose 200 mg/day

Duration 6 weeks

Clinical notes Always combine with streptomycin (first 2–3 weeks) OR rifampicin (full 6 weeks); monotherapy leads to high relapse

1. Malaria Chemoprophylaxis

Parameter Recommendation

PAEDIATRIC DOSING (Specialist Only)

⚠️ Age Restriction

• Generally avoided in children <8 years due to risk of permanent teeth staining and enamel hypoplasia

• Exception: May be used in children <8 years for life-threatening infections (scrub typhus, Rocky Mountain spotted fever, anthrax, severe malaria) when benefits outweigh risks — specialist supervision mandatory

• Recent evidence suggests short courses (≤21 days) may have minimal dental effects, but caution persists in Indian practice

Weight-Based Dosing (Children ≥8 years)

Weight Category Loading Dose (Day 1) Maintenance Dose Maximum Daily Dose

<45 kg 4 mg/kg (divided q12h) 2–4 mg/kg/day (single or divided) 200 mg/day

≥45 kg Adult dosing applies 100 mg once or twice daily 200 mg/day

Primary Paediatric Indications

1. Scrub Typhus / Rickettsial Disease

Parameter Children ≥8 years Children <8 years (life-threatening only)

Dose 2.2 mg/kg twice daily (max 100 mg/dose) 2.2 mg/kg twice daily (max 100 mg/dose)

Duration 7 days or until afebrile 48–72 hours 5–7 days (shortest effective course)

Notes First-line per IAP/ICMR Specialist only; benefits outweigh dental risk in severe disease

1. Malaria Chemoprophylaxis

Parameter Recommendation

Minimum age ≥8 years

Dose 2 mg/kg once daily (max 100 mg)

Duration 1–2 days before travel through 4 weeks after

Notes Alternative when atovaquone-proguanil unavailable

1. Severe Malaria (Adjunct)

Parameter Recommendation

Age ≥8 years (or <8 years if benefits outweigh risks)

Dose 2.2 mg/kg twice daily (max 100 mg/dose)

Duration 7 days

Notes Always combine with IV artesunate; never monotherapy

1. Cholera

Parameter Recommendation

Age ≥8 years

Dose 2–4 mg/kg/day in single or divided doses

Duration Single dose or 3 days

Notes Adjunct to ORS; reduces disease duration

1. Anthrax (Post-Exposure Prophylaxis)

Parameter Recommendation

Age Any age (including <8 years due to severity)

Dose 2.2 mg/kg twice daily (max 100 mg/dose)

Duration 60 days

Notes Life-saving indication overrides dental concerns

Secondary Paediatric Indications (Off-label)

Indication Age Dose Duration Notes

Mycoplasma pneumoniae pneumonia ≥8 years 2 mg/kg twice daily (max 100 mg/dose) 7–10 days OFF-LABEL; when macrolide-resistant suspected

Acne vulgaris (moderate–severe) ≥12 years 50–100 mg once daily 6–12 weeks OFF-LABEL; with topical therapy

Safety Monitoring in Paediatrics

• Monitor for GI upset; administer with food if needed

• Advise upright posture for 30 minutes post-dose

• Sun protection during treatment

• Dental surveillance if used in children <8 years

• Document indication clearly when used off-label or in younger children

No dose adjustment required for most patients.

CRRT Standard dosing; monitor clinically

Clinical Note: Unlike other tetracyclines, doxycycline is primarily excreted via GI tract (chelated in intestines), making it safer in renal impairment.

Clinical Note: Doxycycline may accumulate in hepatic impairment and has rare potential for drug-induced hepatotoxicity.

• Known hypersensitivity to doxycycline, any tetracycline, or excipients

• Pregnancy (second and third trimesters) — absolute contraindication

• Children <8 years — relative contraindication (except life-threatening infections under specialist care)

• Concurrent use with systemic retinoids (isotretinoin, acitretin) — risk of benign intracranial hypertension

• Myasthenia gravis — may exacerbate weakness (use only if no alternative and with close monitoring)

• Oesophageal injury: Administer with adequate water; maintain upright posture for 30 minutes; avoid bedtime dosing

• Photosensitivity: Advise sun avoidance and protective measures

• First trimester pregnancy: Use only if no safer alternative and benefit outweighs risk

• Systemic lupus erythematosus: May exacerbate; use with caution

• History of oral/oesophageal surgery or strictures

• Concurrent hepatotoxic drugs

• Prolonged use: Risk of superinfection (Candida, Clostridioides difficile)

• Intracranial hypertension history

Parameter Details

Risk Category Contraindicated in 2nd and 3rd trimesters

Risk Summary Crosses placenta; causes permanent teeth discoloration (yellow-brown), enamel hypoplasia, and inhibition of bone growth in fetus

First Trimester Limited data; may be used if benefits clearly outweigh risks and no alternative exists

Preferred Alternatives Azithromycin (for chlamydia, atypicals), Amoxicillin (for respiratory infections), Penicillin (for syphilis), Ceftriaxone (for gonorrhoea)

When May Be Used Life-threatening maternal infection with no suitable alternative (e.g., rickettsial disease) — specialist decision

Monitoring If inadvertent exposure, counsel regarding risks; no specific fetal monitoring indicated

Parameter Details

Compatibility Generally compatible for short courses

Milk Levels Low; minimal excretion into breast milk

Infant Absorption Poorly absorbed by infant due to chelation with milk calcium

Preferred Alternatives Azithromycin (if appropriate for indication)

Infant Monitoring Observe for oral candidiasis, loose stools; theoretical dental staining risk with prolonged maternal use is very low

Recommendation Short courses (≤3 weeks) acceptable during breastfeeding; avoid prolonged therapy if possible

Parameter Recommendation

Starting Dose Standard adult dosing (100 mg once or twice daily)

Titration Not applicable

Special Considerations Higher risk of oesophageal ulceration — ensure adequate hydration and upright posture; monitor for pill oesophagitis symptoms (dysphagia, odynophagia, retrosternal pain)

Renal Function No dose adjustment typically needed

Drug Interactions Review concurrent medications (antacids, iron, calcium supplements, anticoagulants)

Adverse Effects Monitor for Clostridioides difficile infection; may be more susceptible

Interacting Drug Effect Mechanism Recommendation

Isotretinoin / Acitretin Risk of benign intracranial hypertension (pseudotumour cerebri) Additive effect on intracranial pressure AVOID combination

Methotrexate Increased methotrexate toxicity Decreased renal clearance; displaced protein binding Avoid or use with extreme caution; monitor closely

Warfarin / Acenocoumarol Enhanced anticoagulant effect; increased bleeding risk Altered gut flora reducing vitamin K synthesis; possible CYP inhibition Monitor INR closely; may need warfarin dose reduction

Ciclosporin Increased ciclosporin levels Unknown mechanism Monitor ciclosporin levels

Antacids (Al/Mg/Ca-containing) Markedly reduced doxycycline absorption Chelation in GI tract Separate by at least 2–3 hours

Oral iron preparations Reduced absorption of both drugs Mutual chelation Separate by at least 2–3 hours

Calcium supplements / Dairy Reduced doxycycline absorption Chelation Separate by 2 hours; or take doxycycline with low-calcium meal

Sucralfate Reduced doxycycline absorption Physical binding Separate by at least 2 hours

Quinapril Reduced quinapril absorption Contains magnesium carbonate excipient Separate administration

Interacting Drug Effect Recommendation

Rifampicin Reduced doxycycline levels (half-life reduced by ~50%) May need doxycycline 100 mg twice daily instead of once daily; monitor clinical response

Phenytoin / Carbamazepine / Phenobarbital Reduced doxycycline efficacy Enzyme induction; consider higher doxycycline dose or twice daily dosing

Oral contraceptives Theoretical reduced efficacy (controversial) Limited evidence; advise additional contraception during antibiotic course and 7 days after (as per standard practice)

Theophylline Possible increased GI adverse effects Monitor for nausea, vomiting

Digoxin Possible increased digoxin levels (in ~10% patients) Monitor digoxin levels if signs of toxicity

Penicillins Possible antagonism (bacteriostatic vs bactericidal) Clinical significance uncertain; avoid in severe infections like endocarditis/meningitis if possible

Lithium Possible increased lithium levels Monitor lithium levels

Kaolin-pectin antidiarrhoeals Reduced doxycycline absorption Separate by 2 hours

• Nausea, vomiting

• Epigastric discomfort, dyspepsia

• Diarrhoea

• Photosensitivity (phototoxic dermatitis)

• Oesophageal irritation / ulceration

• Vaginal candidiasis

• Oral candidiasis (thrush)

• Headache

• Skin rash (non-serious)

Adverse Effect Clinical Notes

Benign intracranial hypertension (pseudotumour cerebri) Headache, visual disturbances, papilloedema; discontinue immediately

Stevens-Johnson syndrome / Toxic epidermal necrolysis Rare; discontinue immediately; hospitalisation required

Drug-induced hepatotoxicity Monitor LFTs; discontinue if significant elevation

Clostridioides difficile colitis May occur during or weeks after therapy; discontinue and treat appropriately

Severe photosensitivity / phototoxic bullous eruption Discontinue; supportive care

Oesophageal ulceration / stricture Odynophagia, retrosternal pain; prevention is key

Exacerbation of myasthenia gravis Worsening weakness; avoid in known MG

Hypersensitivity reactions / Anaphylaxis Rare; standard management

Permanent teeth discoloration In children <8 years; enamel hypoplasia

During Therapy Clinical response; signs of oesophageal irritation; skin for photosensitivity; signs of superinfection

Long-term Use (>3 months) LFTs every 2–3 months; monitor for C. difficile symptoms; periodic dental check in younger patients

If on Anticoagulants INR within 3–5 days of starting and after stopping

Symptoms of Intracranial Hypertension Immediate ophthalmological evaluation if headache, visual changes, papilloedema

Single-Ingredient Brands

Doxt Dr. Reddy's Capsules 100 mg

Doxycee Cipla Capsules 100 mg

Doxy-1 Micro Labs Capsules/Tablets 100 mg

Microdox Micro Labs Capsules 100 mg

Doxrid Ridley Life Sciences Capsules 100 mg

Biodoxi Biochem Capsules 100 mg

Tetradox Alkem Capsules 100 mg

Doxybond Mankind Capsules 100 mg

Doxiford Intas Capsules 100 mg

Fixed-Dose Combinations (Common)

Brand Name Combination Use

• NLEM Status: Doxycycline is included in National List of Essential Medicines (NLEM) 2022

• DPCO Price Control: Subject to price ceiling under DPCO

• Government Supply: Available in public health facilities under national programmes (NVBDCP, RNTCP TB-HIV)

1. First-line for scrub typhus — Critical to recognise rickettsial illness in endemic areas (Himalayan belt, NE India, South India); do not wait for serology to initiate treatment in clinically suspected cases

1. Take upright with full glass of water — Most common preventable ADR is oesophageal ulceration; advise patients to remain upright 30 minutes post-dose and avoid bedtime administration

1. Food minimally affects absorption — Unlike other tetracyclines, doxycycline can be given with food to reduce GI upset (except high-calcium meals/dairy)

1. Photosensitivity counselling — Less photosensitive than other tetracyclines but still significant; advise sunscreen SPF 30+, protective clothing, avoidance of prolonged sun exposure

1. Preferred tetracycline in renal impairment — Primary excretion via intestinal chelation, not kidneys; safe to use without dose adjustment in CKD

1. STI syndromic management — For urethral/cervical discharge, combine with ceftriaxone 250 mg IM (single dose) to cover both gonorrhoea and chlamydia per NACO guidelines

1. Acne duration — Limit oral antibiotic courses to 6–12 weeks; always combine with topical retinoid and benzoyl peroxide to reduce resistance emergence

tetracycline; antibacterial; scrub-typhus; rickettsial; malaria-prophylaxis; STI; chlamydia; cholera; acne; rosacea; NLEM-India; photosensitivity-risk; avoid-pregnancy

RxIndia v0.1 — 27 Jan 2025

• CDSCO approved prescribing information for Doxycycline

• Indian Pharmacopoeia 2022

• NLEM India 2022

• NCDC Treatment Modules — Scrub Typhus, Cholera, Plague

• NVBDCP Guidelines — Malaria Chemoprophylaxis and Treatment

• NACO STI/RTI Technical Guidelines 2014 (updated)

• ICMR — Rickettsial Disease Guidelines

• API Textbook of Medicine (11th Edition) — Rickettsial infections, Leptospirosis, Brucellosis

• IAP Textbook of Pediatrics — Antimicrobial dosing

• Goodman & Gilman's The Pharmacological Basis of Therapeutics (14th Edition)

• Harrison's Principles of Internal Medicine (21st Edition)

• BLISTER trial (off-label bullous pemphigoid reference)