Doxyclen Special Precautions

General: As with other antibacterial drugs, use of Doxycycline may result in overgrowth of non susceptible organisms, including fungi. If superinfection occurs, Doxycycline should be discontinued and appropriate therapy instituted. Incision and drainage or other surgical procedures should be performed in conjunction with antibacterial therapy, when indicated.
Doxycycline offers substantial but not 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 proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.
Information For Patients: Patients taking doxycycline for malaria prophylaxis should be advised: that no present-day antimalarial agent, including doxycycline, guarantees protection against malaria.
To avoid being bitten by mosquitoes by using personal protective measures that help avoid contact with mosquitoes, especially from dusk to dawn (e.g., staying in well-screened areas, using mosquito nets, covering the body with clothing, and using an effective insect repellent).
That Doxycycline prophylaxis: should begin 1-2 days before travel to the malarious area, should be continued daily while in the malarious area and after leaving the malarious area, should be continued for 4 further weeks to avoid development of malaria after returning from an endemic area, should not exceed 4 months.
All patients taking doxycycline should be advised: to avoid excessive sunlight or artificial ultraviolet light while receiving doxycycline and to discontinue therapy if phototoxicity (e.g., skin eruption, etc.) occurs. Sunscreen or sunblock should be considered.
To drink fluids liberally along with doxycycline to reduce the risk of esophageal irritation and ulceration.
That the absorption of tetracyclines is reduced when taken with foods, especially those which contains calcium. However, the absorption of doxycycline is not markedly influenced by simultaneous ingestion of food or milk.
That the absorption of tetracyclines is reduced when taking bismuth subsalicylate.
That the use of doxycycline might increase the incidence of vaginal candidiasis.
Patients should be counseled that antibacterial drugs, including Doxycycline should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When Doxycycline is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed.
Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by Doxycycline or other antibacterial drugs in the future.
Diarrhea is a common problem caused by antibacterial drugs, which usually ends when the antibacterials are discontinued. Sometimes after starting treatment with antibacterial drugs, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibacterial drug. If this occurs, patients should contact their physician as soon as possible.
Laboratory Tests: In venereal disease, when co-existent 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, periodic laboratory evaluation of organ systems, including hematopoietic, renal, and hepatic studies, should be performed.
Use in Children: Because of the effects of drugs of the tetracycline-class on tooth development and growth, use doxycycline in pediatric 8 years of age or less only when the potential benefits are expected to outweigh the risks in severe or life-threatening conditions (e.g., anthrax, Rocky Mountain spotted fever), particularly when there are no alternative therapies.