Doxycycline – A Complete Guide

Doxycycline is a tetracycline-class antimicrobial used to treat infections that are proven to be caused by susceptible bacteria. This reduces the development of drug-resistant bacteria and maintains the effectiveness of doxycycline.

Doxycycline shouldn’t be used in persons who have shown hypersensitivity to any of the tetracyclines.

It is used to treat the following diseases:

• Rickettsial infections

• Sexually transmitted infections

• Respiratory tract infections

• Specific bacterial infections

• Ophthalmic infections

• Anthrax including inhalational anthrax

• Infections caused by Clostridium species

• Adjunctive therapy for acute intestinal amebiasis and severe acne In acute intestinal amebiasis adjunctive therapy

• Prophylaxis of malaria

• For adults: the usual dose of oral doxycycline is 200 mg on the first day of treatment (given 100 mg every 12 hours) followed by a maintenance dose of 100 mg/day. The maintenance dose may be given as a single dose or as 50 mg every 12 hours. For more severe infections (mainly chronic infections of the urinary tract), 100 mg every 12 hours is recommended.

• For children above eight years of age: the recommended dosage for children weighing 45 kg or less is 4.4 mg/kg of body weight divided into two doses on the first day of treatment, followed by 1 mg/lb of body weight given as a single daily dose or divided into two doses on subsequent days. For more severe infections up to 4.4 mg/kg of body weight may be used. For children over 45 kg, the usual adult dose should be used.

• For streptococcal infections: therapy should be continued for 10 days.

• Uncomplicated urethral, endocervical, or rectal infection in adults caused by Chlamydia trachomatis: 100 mg by mouth twice a day for 7 days.

• Nongonococcal urethritis caused by C. trachomatis and U. urealyticum: 100 mg by mouth twice a day for 7 days.

• Syphilis:
  • Syphilis (early): doxycycline 100 mg by mouth twice a day for 2 weeks.
  • Syphilis (more than 1 year): doxycycline 100 mg by mouth twice a day for 4 weeks.
  • Acute epididymal-orchitis: 100 mg by mouth, twice a day for at least 10 days.

• For prophylaxis of malaria:
  • For adults: the recommended dose is 100 mg daily.
  • For children over 8 years of age: the recommended dose is 2 mg/kg given once daily up to the adult dose.

• Inhalational anthrax (post-exposure): for adults, 100 mg, of doxycycline, by mouth, twice a day for 60 days. For children weighing less than 45 kg by mouth, twice a day for 60 days. Children weighing 45 kg or more should receive the adult dose.

• Sprinkling the tablet over applesauce: is another way of administering doxycycline.

• Gastrointestinal: Anorexia, nausea, vomiting, diarrhea, glossitis, dysphagia, enterocolitis, and inflammatory lesions in the anogenital region. Hepatotoxicity has been reported rarely.

• Skin: Maculopapular and erythematous rashes. Exfoliative dermatitis has been reported but is uncommon.

• Renal: Rise in BUN has been reported and is apparently dose-related.

• Hypersensitivity reactions: Urticaria, anaphylactoid purpura, serum sickness, pericarditis, angioneurotic edema, anaphylaxis, and exacerbation of systemic lupus erythematosus.

• Blood: Hemolytic anemia, neutropenia, thrombocytopenia, and eosinophilia have been reported.

• Benign Intracranial Hypertension: bulging fontanels in infants and benign intracranial hypertension in adults.

• Thyroid Gland Changes: When given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discoloration of thyroid glands.

The use of tetracycline drugs during tooth development may cause permanent discolouration of the teeth.

Clostridium difficile-associated diarrhea (CDAD) has been reported with the of doxycycline and may range in severity from mild diarrhea to fatal colitis.

Photosensitivity is another side effect some individuals can experience while taking tetracyclines. So patients should make sure to use sunscreen every day.

Doxycycline may result in the overgrowth of nonsusceptible organisms, including fungi.

Benign intracranial hypertension in adults and bulging fontanels in infants have been reported in individuals receiving tetracyclines. These conditions disappeared when the drug was discontinued.

All tetracyclines form a stable calcium complex in any bone-forming tissue. A decrease in fibula growth rate has been observed in premature given oral tetracycline in doses of 25 mg/kg every six hours. This reaction was shown to be reversible when the drug was discontinued.

The antianabolic action of the tetracyclines may cause an increase in BUN.

Incision and drainage or other surgical procedures should be performed along with antibiotic therapy when indicated.

Doxycycline does not offer complete suppression of the asexual blood stages of Plasmodium strains. Doxycycline does not suppress P. falciparum’s sexual blood stage gametocytes. Subjects completing this prophylactic regimen may still transmit the infection to mosquitoes outside endemic areas.

Prescribing doxycycline in the absence of a strongly suspected bacterial infection or a prophylactic indication increases the risk of the development of drug-resistant bacteria.

In venereal disease when coexistent syphilis is suspected, dark-field examinations should be done before treatment is started and the blood serology repeated monthly for at least 4 months.

In long-term therapy, evaluation of organ systems, including hematopoietic, renal, and hepatic studies should be performed.

Yes, doxycycline can cause purging for some people and can last for 4-6 weeks.

Yes, doxycycline can be used for rosacea and is completely safe. For the short term, the recommended dosage would be 100mg or 200mg a day and for the long term, the recommended dosage would be 40mg a day.

Yes, doxycycline can be used for perioral dermatitis and is completely safe. The recommended dosage is 100mg a day for the short term and 40mg a day for the short term. Your perioral dermatitis might become worse before better when starting doxycycline.

Doxycycline can be used for seborrheic dermatitis but it will only work for some people. Many people have said doxycycline can make your seborrheic dermatitis worse while others said it worked for them.

Yes, doxycycline can be used to treat hormonal acne and is completely safe.

Yes, a low dosage of 40mg a day can help to treat ocular rosacea.

Yes, doxycycline can be used for hidradenitis suppurativa and it helps to keep flare-ups at bay. However, it cannot be used long-term and you should make sure to use it only when a flare-up occurs.

No, doxycycline shouldn’t be used to treat psoriasis as it could worsen the disease.

Yes, doxycycline can be used to treat bacterial vaginosis and a lot of people have had positive experiences with it.

Joint pain is a common side effect a lot of people have experienced with doxycycline. The joint pain should go away once you have completed your treatment.

Yes, doxycycline can be used to treat scalp folliculitis but it will come back once you have completed your treatment.

Yes, doxycycline can be used for chlamydia and is very effective. If doxycycline doesn’t work for chlamydia, then try using azithromycin.