Oral
Susceptible infections
Oral
Topical/Cutaneous
Dosage/Direction for Use
Oral Susceptible infections Oral Topical/Cutaneous |
Administration
May be taken with or without food. Take w/ a full glass of water & remain upright for at least 30 min. Take w/ food or milk if GI irritation occurs.
|
Contraindications
Hypersensitivity to doxycycline and other tetracycline congeners. Known or suspected achlorhydria (film-coated tab). Children <8 years (except for anthrax). Pregnancy and lactation. Concomitant use of methoxyflurane.
|
Special Precautions
Patient with coexisting venereal disease, myasthenia gravis, SLE; history or predisposition to oral candidosis (film-coated tab). Hepatic and renal impairment. Patient Counselling Avoid exposure to direct sunlight or UV light. Monitoring Parameters Before treatment, perform sensitivity testing. Monitor CBC, LFT and renal function.
|
Adverse Reactions
Significant: Microbial overgrowth including fungi, pseudomembranous colitis, oesophagitis, oesophageal ulceration, benign intracranial hypertension, discolouration of teeth, enamel hypoplasia, photosensitivity, exfoliative dermatitis, erythema multiforme, drug reaction with eosinophilia and systemic symptoms, Jarisch-Herxheimer reaction (if with spirochete infection); rarely, transient increases in LFT, porphyria.
Blood and lymphatic system disorders: Haemolytic anaemia, neutropenia, eosinophilia, thrombocytopenia.
Cardiac disorders: Tachycardia, pericarditis.
Ear and labyrinth disorders: Tinnitus.
Eye disorders: Blurred vision, diplopia, scotomata.
Gastrointestinal disorders: Stomatitis, nausea, vomiting, diarrhoea, dyspepsia, abdominal pain, pancreatitis.
General disorders and administration site conditions: Peripheral oedema.
Hepatobiliary disorders: Jaundice.
Immune system disorders: Angioneurotic oedema, urticaria, serum sickness.
Investigations: Brown/black discolouration of thyroid tissue, increased serum AST.
Metabolism and nutrition disorders: Anorexia.
Musculoskeletal and connective tissue disorders: Arthralgia, myalgia.
Nervous system disorders: Headache.
Reproductive system and breast disorders: Vaginitis.
Respiratory, thoracic and mediastinal disorders: Dyspnoea.
Skin and subcutaneous tissue disorders: Rashes, photo-onycholysis, skin hyperpigmentation.
Vascular disorders: Hypotension.
Potentially Fatal: Anaphylactoid reactions, Stevens-Johnson syndrome, toxic epidermal necrolysis, Clostridium difficile-associated disease (CDAD), hepatotoxicity. |
Drug Interactions
Risk of pseudotumour cerebri with isotretinoin. Risk of breakthrough bleeding with oral contraceptives. Prolonged prothrombin time with anticoagulants (e.g. warfarin). Decreased exposure with antacids containing Al, Ca or Mg, Zn, Fe salts, bismuth preparations, carbamazepine, phenobarbital, phenytoin and primidone. May increase the exposure of ciclosporin. May interfere with the bactericidal action of penicillin. Drugs that induce hepatic enzymes (e.g. rifampicin) may decrease the half-life of doxycycline.
Potentially Fatal: Concurrent use with methoxyflurane may result in renal toxicity. |
Food Interaction
May decrease absorption with food including milk. Decreased half-life with alcohol.
|
Lab Interference
May interfere with fluorescence test for urinary catecholamines.
|
Action
Doxycycline, a tetracycline congener, is bacteriostatic against a broad range of gram-positive and gram-negative bacteria. It inhibits protein synthesis by inhibiting the 30S ribosomal subunit of bacteria.
Absorption: Readily and almost completely absorbed from the gastrointestinal tract. Bioavailability: Approx 93%. Time to peak plasma concentration: 2 hours. Distribution: Widely distributed into body tissues (with strong affinity to lung and renal tissues) and fluids. Crosses the placenta and enters breast milk. Plasma protein binding: Approx 80-95%. Excretion: Via urine (23%-40%); faeces (30%). Plasma elimination half-life: 12-24 hours. |
Storage
Intravenous: Store between 20-25°C. Protect reconstituted solution from light. Oral: Store between 20-25°C. Topical/Cutaneous: Store between 20-25°C.
|
CIMS Class
|
ATC Classification
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. |