DOXYCYCLINE

Indications & Dose:

 Rocky Mountain spotted fever; typhus fever and the typhus group; Q fever; rickettsialpox; tick fevers caused by Rickettsiae; respiratory tract infections; lymphogranuloma venereum; psittacosis (ornithois); trachoma; inclusion conjunctivitis; uncomplicated urethral, endocervical, or rectal infections in adults; nongonococcal urethritis; relapsing fever; chancroid; plague; tularemia; cholera; Campylobacter fetus infections; brucellosis; bartonellosis; granuloma inguinale; malaria prophylaxis, acne, periodontitis subgingival scaling and root planing in adults

DOSE

Usually 200mg on first day, then 100mg daily; severe infections (including chronic urinary tract infections) 200mg daily.

* Early syphilis 100mg twice daily for 14 days, late latent syphilis 200mg twice daily for 28 days.

* Uncomplicated genital chlamydia, non gonococcal urethritis 100mg twice daily for 7 days (14 days in pelvic inflammatory disease

* Anthrax, 100mg twice daily.

Acne, 50mg daily for 6-12 weeks or longer .capsules should be swallowed whole with plenty of fluid during meals while sitting or standing.

Children

5mg/kg/24 hours divided every 12 hour. Avoid use in children below 8 years.

Contraindications:

 Children <8 yr.

Side Effects:

Cautions:

Precautions:

 Hepatic disease, prolonged or repeated therapy 

Interaction:

Drugs

Antacids: Reduced serum concentration and efficacy of doxycycline

Barbiturates: Reduced serum doxycycline concentrations

Bismuth: Reduced bioBrands Available with Cost of doxycycline

Calcium: See antacids

Carbamazepine: Reduced serum doxycycline concentrations 

Cholestyramine; colestipol: Reduced serum concentration of doxycycline; take 2 hr before or 3 hr after resin dose

Ethanol: Chronic ethanol ingestion may reduce the serum concentrations of doxycycline

Iron: Reduced serum concentration and efficacy of doxycycline

Magnesium: See antacids

Oral contraceptives: Potential for decreased efficacy of oral con traceptives

Penicillins: Doxycycline may reduce penicillin efficacy

Phenytoin: Reduced serum doxycycline concentrations

Warfarin: Potential for enhanced hypoprothrombinemic response to warfarin

Zinc: Reduced serum concentration of doxycycline; take 2 hr before or 3 hr after zinc 

Warnings:

Adverse Effects:

Lactations:

 Excreted into breast milk; theoretical possibility for dental staining seems remote because serum levels in infant undetectable 

Special Precautions:

Counselling:

Side Effects Or Adverse Reactions:

CNS: Fever, headache, paresthesia

CV: Pericarditis

GI: Abdominal cramps, abdominal pain, anorexia, diarrhea, enterocolitis, epigastric burning, flatulence, glossitis, hepatotoxicity, nausea, pseudomembranous colitis, stomatitis, vomiting

GU: Azotemia, increased PUN, polydipsia, polyuria

HEME: Eosinophilia, hemolytic anemia, neutropenia, thrombocytopenia

SKIN: Exfoliative dermatitis, highly irritating (avoid extravasation), photosensitivity, pruritus, rash, urticaria

MISC.: Angioedema, bulging fontanels (infants), decreased calcification of deciduous teeth, pseudoturmor cerebri (adults) 

Patient And Carer Advice: