Doxycycline

Oral
Susceptible infections
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: Usual dose: 200 mg on the 1st day (given as a single dose or in 2 divided doses at 12-hour interval), followed by a maintenance dose of 100 mg daily. For more severe infections: 200 mg daily given throughout treatment. For streptococcal infections, continue treatment for 10 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.
Child: As conventional cap, conventional or delayed-release tab, or oral susp: Acute infections: 8-<12 years ≤45 kg: 4.4 mg/kg on the 1st day (given as a single dose or in 2 divided doses), followed by maintenance dose of 2.2 mg/kg daily (given as a single dose or in 2 divided doses); >45 kg: Same as adult dose. 12-<18 years Same as adult dose. For more severe infections: 8-<12 years ≤45 kg: Up to 4.4 mg/kg given throughout treatment; >45 kg: Same as adult dose. 12-<18 years Same as adult dose. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Susceptible Gram-negative infections
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: Usual dose: 200 mg on the 1st day (given as a single dose or in 2 divided doses at 12-hour interval), followed by a maintenance dose of 100 mg daily. For more severe infections: 200 mg daily given throughout treatment. For streptococcal infections, continue treatment for 10 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.
Child: As conventional cap, conventional or delayed-release tab, or oral susp: Acute infections: 8-<12 years ≤45 kg: 4.4 mg/kg on the 1st day (given as a single dose or in 2 divided doses), followed by maintenance dose of 2.2 mg/kg daily (given as a single dose or in 2 divided doses); >45 kg: Same as adult dose. 12-<18 years Same as adult dose. For more severe infections: 8-<12 years ≤45 kg: Up to 4.4 mg/kg given throughout treatment; >45 kg: Same as adult dose. 12-<18 years Same as adult dose. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Susceptible Gram-positive infections
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: Usual dose: 200 mg on the 1st day (given as a single dose or in 2 divided doses at 12-hour interval), followed by a maintenance dose of 100 mg daily. For more severe infections: 200 mg daily given throughout treatment. For streptococcal infections, continue treatment for 10 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.
Child: As conventional cap, conventional or delayed-release tab, or oral susp: Acute infections: 8-<12 years ≤45 kg: 4.4 mg/kg on the 1st day (given as a single dose or in 2 divided doses), followed by maintenance dose of 2.2 mg/kg daily (given as a single dose or in 2 divided doses); >45 kg: Same as adult dose. 12-<18 years Same as adult dose. For more severe infections: 8-<12 years ≤45 kg: Up to 4.4 mg/kg given throughout treatment; >45 kg: Same as adult dose. 12-<18 years Same as adult dose. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Acne vulgaris
Adult: As conventional cap or tab: 50-100 mg daily for 6-12 weeks. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Uncomplicated urethral infections caused by Chlamydia trachomatis
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Uncomplicated endocervical infections caused by Chlamydia trachomatis
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Uncomplicated rectal infections caused by Chlamydia trachomatis
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Uncomplicated gonorrhoea
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Nongonococcal urethritis
Adult: For the treatment of cases caused by Ureaplasma urealyticum or Chlamydia trachomatis: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Epididymo-orchitis
Adult: For the treatment of acute cases caused by Chlamydia trachomatis or Neisseria gonorrhoeae: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 10 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Primary syphilis
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: As an alternative therapy in non-pregnant penicillin-allergic patients: 100 mg or 200 mg bid for 2 weeks. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Secondary syphilis
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: As an alternative therapy in non-pregnant penicillin-allergic patients: 100 mg or 200 mg bid for 2 weeks. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Louse-borne relapsing fever
Adult: As conventional cap or tab: 100 mg or 200 mg as a single dose according to severity. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Tick-borne relapsing fever
Adult: As conventional cap or tab: 100 mg or 200 mg as a single dose according to severity. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Chloroquine-resistant falciparum malaria
Adult: As conventional cap or tab: In combination with a rapid-acting schizonticide (e.g. quinine): 200 mg daily for at least 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Prophylaxis of malaria
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg daily beginning 1-2 days before travel to the malarious area, continued daily during travel and for 4 weeks after leaving the area. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.
Child: As conventional cap, conventional or delayed-release tab, or oral susp: >8 years 2 mg/kg once daily up to the adult dose, beginning 1-2 days before travel to malarious area, continued daily during travel and for 4 weeks after leaving the area. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Prophylaxis of scrub typhus
Adult: As conventional cap or tab: 200 mg as a single dose. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Prophylaxis of traveller's diarrhoea
Adult: As conventional cap or tab: 200 mg on the 1st day of travel (given as a single dose or as 100 mg 12 hourly), followed by 100 mg daily throughout the stay in the area. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Leptospirosis
Adult: For prophylaxis: As conventional cap or tab: 200 mg once weekly throughout the stay in the area for up to 21 days and 200 mg at the completion of the trip. For treatment: As conventional tab: 100 mg bid for 7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Rocky Mountain spotted fever
Adult: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg 12 hourly. Continue for at least 3 days after the fever subsides and until there is evidence of clinical improvement. Minimum duration: 5-7 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.
Child: As conventional cap, conventional or delayed-release tab, or oral susp: <45 kg: 2.2 mg/kg bid; ≥45 kg: Same as adult dose. Continue for at least 3 days after the fever subsides and until there is evidence of clinical improvement. Minimum duration: 5-7 days.

Oral
Rosacea
Adult: To reduce papulopustular lesions: As 40 mg modified-release cap: 40 mg once daily in the morning, preferably at least 1 hour before or 2 hours after meals. Evaluate after 6 weeks; consider discontinuing treatment if no effect is seen. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.

Oral
Inhalational anthrax
Adult: Postexposure prophylaxis: As conventional cap, conventional or delayed-release tab, or oral susp: 100 mg bid for 60 days. Dosage recommendations and indications may vary among countries or individual products. Refer to specific product guidelines.
Child: Postexposure prophylaxis: As conventional cap, conventional or delayed-release tab, or oral susp: <45 kg: 2.2 mg/kg bid for 60 days; ≥45 kg: Same as adult dose.

Oral
Periodontitis
Adult: As adjunct to supragingival and subgingival scaling and root planing: As 20 mg conventional tab: 20 mg bid for 3-9 months. Doses to be taken at least 1 hour before or 2 hours after meals.

Intravenous
Susceptible Gram-positive infections
Adult: 200 mg on the 1st day given in 1 or 2 infusions, followed by 100-200 mg daily depending on the severity of the infection. Doses are given via infusion over 1-4 hours (depending on the dose).
Child: >8 years ≤45 kg: 4.4 mg/kg in 2 divided doses on the 1st day, followed by maintenance dose of 2.2 mg/kg daily (given as a single dose or in 2 divided doses); >45 kg: Same as adult dose. For severe infections: <45 kg: 2.2 mg/kg 12 hourly; ≥45 kg: Same as adult dose.
Reconstitution: IV: Reconstitute the contents of the vial by adding 10 mL of sterile water for inj or any compatible IV solution for each 100 mg of doxycycline to make a solution containing 10 mg/mL. Withdraw the entire solution from the 100 mg vial and dilute further with 100-1,000 mL of a compatible IV solution to a final concentration of 0.1-1 mg/mL.
Incompatibility: Preparations of doxycycline hyclate are incompatible with alkaline preparations or with drugs unstable at low pH.

Intravenous
Susceptible Gram-negative infections
Adult: 200 mg on the 1st day given in 1 or 2 infusions, followed by 100-200 mg daily depending on the severity of the infection. Doses are given via infusion over 1-4 hours (depending on the dose).
Child: >8 years ≤45 kg: 4.4 mg/kg in 2 divided doses on the 1st day, followed by maintenance dose of 2.2 mg/kg daily (given as a single dose or in 2 divided doses); >45 kg: Same as adult dose. For severe infections: <45 kg: 2.2 mg/kg 12 hourly; ≥45 kg: Same as adult dose.
Reconstitution: IV: Reconstitute the contents of the vial by adding 10 mL of sterile water for inj or any compatible IV solution for each 100 mg of doxycycline to make a solution containing 10 mg/mL. Withdraw the entire solution from the 100 mg vial and dilute further with 100-1,000 mL of a compatible IV solution to a final concentration of 0.1-1 mg/mL.
Incompatibility: Preparations of doxycycline hyclate are incompatible with alkaline preparations or with drugs unstable at low pH.

Intravenous
Susceptible infections
Adult: 200 mg on the 1st day given in 1 or 2 infusions, followed by 100-200 mg daily depending on the severity of the infection. Doses are given via infusion over 1-4 hours (depending on the dose).
Child: >8 years ≤45 kg: 4.4 mg/kg in 2 divided doses on the 1st day, followed by maintenance dose of 2.2 mg/kg daily (given as a single dose or in 2 divided doses); >45 kg: Same as adult dose. For severe infections: <45 kg: 2.2 mg/kg 12 hourly; ≥45 kg: Same as adult dose.
Reconstitution: IV: Reconstitute the contents of the vial by adding 10 mL of sterile water for inj or any compatible IV solution for each 100 mg of doxycycline to make a solution containing 10 mg/mL. Withdraw the entire solution from the 100 mg vial and dilute further with 100-1,000 mL of a compatible IV solution to a final concentration of 0.1-1 mg/mL.
Incompatibility: Preparations of doxycycline hyclate are incompatible with alkaline preparations or with drugs unstable at low pH.

Intravenous
Inhalational anthrax
Adult: Postexposure treatment: 100 mg bid via infusion over 1-4 hours. Substitute oral therapy as soon as possible and continue for a total of 60 days.
Child: Postexposure treatment: <45 kg: 2.2 mg/kg bid via infusion over 1-4 hours. Substitute oral therapy as soon as possible and continue for a total of 60 days.
Reconstitution: IV: Reconstitute the contents of the vial by adding 10 mL of sterile water for inj or any compatible IV solution for each 100 mg of doxycycline to make a solution containing 10 mg/mL. Withdraw the entire solution from the 100 mg vial and dilute further with 100-1,000 mL of a compatible IV solution to a final concentration of 0.1-1 mg/mL.
Incompatibility: Preparations of doxycycline hyclate are incompatible with alkaline preparations or with drugs unstable at low pH.

Doxycycline: May be taken with or without food. May be taken w/ meals to decrease GI upset. Take w/ at least 240 mL of water & sit up for at least 30 min-2 hr after to reduce the risk of oesophageal irritation & ulceration. Cap: Swallow whole, do not open/break/crush/dissolve/chew.
Doxycycline: Should be taken with food. For acne vulgaris: Take w/ food/fluid. Take w/ adequate amount of water to reduce risk of oesophageal irritation & ulceration.

Hypersensitivity to doxycycline or other tetracyclines. Pregnancy and lactation. Concomitant treatment with methoxyflurane and isotretinoin or other systemic retinoids.

Patient with myasthenia gravis, SLE, history of intracranial hypertension. Women of childbearing age who are overweight. Patient with history of or predisposition to oral candidiasis (for periodontitis indication). Hepatic impairment. Children. Patient Counselling Avoid excessive exposure to sunlight or artificial UV light, consider applying sunscreen or wear protective clothing when going outdoors. Monitoring Parameters Perform culture and susceptibility tests; consult local institutional recommendations before treatment initiation due to antibiotic resistance risks. Monitor CBC, hepatic and renal functions periodically with prolonged therapy. In patients with venereal disease when co-existing syphilis is suspected: Perform dark field examinations before initiating treatment and repeat blood serology monthly for at least 4 months.

Significant: Permanent discolouration (yellow-grey-brown) of the teeth (when given during tooth development [last half of pregnancy; infancy and childhood to the age of 8 years]), enamel hypoplasia, photosensitivity, benign intracranial hypertension (pseudotumour cerebri), overgrowth of nonsusceptible organisms (including fungi), exacerbation of SLE; Jarisch-Herxheimer reaction (particularly in some patients with spirochete infections); may decrease fibula growth rate (particularly in premature infants). Rarely, oesophagitis and oesophageal ulceration (cap/tab); porphyria, photoonycholysis. Blood and lymphatic system disorders: Haemolytic anaemia, thrombocytopenia, neutropenia, eosinophilia. Gastrointestinal disorders: Nausea, vomiting, diarrhoea, upper abdominal pain, dry mouth, dysphagia, glossitis, black hairy tongue; periodontal abscess, tooth disorder, toothache. General disorders and administration site conditions: Pain. Hepatobiliary disorders: Cholestatic hepatitis, fatty liver degeneration. Immune system disorders: Hypersensitivity reactions (e.g. urticaria, angioneurotic oedema, anaphylaxis, anaphylactoid purpura, serum sickness, pericarditis). Investigations: Increased lactate dehydrogenase, blood glucose, AST, or BUN; brown-black microscopic discolouration of thyroid gland (prolonged use). Metabolism and nutrition disorders: Anorexia. Musculoskeletal and connective tissue disorders: Back pain. Nervous system disorders: Headache, dizziness; bulging fontanelles (in infants). Psychiatric disorders: Anxiety. Respiratory, thoracic and mediastinal disorders: Nasopharyngitis, sinusitis. Skin and subcutaneous tissue disorders: Rash (e.g. maculopapular, erythematous or morbilliform rash), nail discolouration. Vascular disorders: Hypertension.
Potentially Fatal: Serious skin reactions (e.g. exfoliative dermatitis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms [DRESS]), pseudomembranous colitis, Clostridium difficile-associated diarrhoea (CDAD).

Absorption may be impaired by concurrently administered antacids or other drugs containing Al, Ca, or Mg; oral Zn, Fe salts, or bismuth preparations. May interfere with the bactericidal action of penicillin. May potentiate the effects of anticoagulants. Reduced half-life with barbiturates, rifampicin, carbamazepine, and phenytoin. May diminish the efficacy of oral contraceptives and breakthrough bleeding may occur. May increase the plasma concentration of ciclosporin. May potentiate the hypoglycaemic effect of sulfonylureas.
Potentially Fatal: Concurrent use with methoxyflurane may result in renal toxicity. May increase the risk of benign intracranial hypertension when given concomitantly with isotretinoin or other systemic retinoids.

Alcohol may reduce the half-life of doxycycline.

May interfere with fluorescence test resulting in false elevations of urinary catecholamine levels.

Doxycycline, a tetracycline congener, has bacteriostatic activity against a broad range of gram-positive and gram-negative bacteria. It inhibits protein synthesis by binding to the 30S ribosomal subunit of the bacteria. It may also cause alterations in the cytoplasmic membrane. In adults with periodontitis, doxycycline has been noted to decrease the elevated collagenase activity in the gingival crevicular fluid.
Absorption: Readily and almost completely absorbed from the gastrointestinal tract. Time to peak plasma concentration: 2-3 hours.
Distribution: Widely distributed in body tissues and fluids with excellent penetration into the kidney, liver, and sinuses; moderately penetrates into CSF. Crosses the placenta and enters breast milk. Plasma protein binding: Approx 80-95%.
Excretion: Via urine (40-60%, as unchanged drug); faeces (approx 30%, as unchanged drug). Elimination half-life: 12-24 hours.

Intravenous: Store intact vials between 20-25°C. Protect from light and moisture. Storage recommendations may vary among countries or individual products. Refer to specific product guidelines. Oral: Cap: Store below 30°C. Storage recommendations may vary among countries or individual products. Refer to specific product guidelines.

Acne Treatment Preparations / Tetracyclines

A01AB22 - doxycycline ; Belongs to the class of local antiinfective and antiseptic preparations. Used in the treatment of diseases of the mouth.
J01AA02 - doxycycline ; Belongs to the class of tetracyclines. Used in the systemic treatment of infections.