Disclaimer: This article is for informational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.
Overview
Doxycycline is a prescription antibiotic from the tetracycline family. In Canada it is sold as 100 mg tablets and capsules under brand names such as Vibramycin and Vibra-Tabs, and as many generic versions. It works against a wide range of bacteria.
It is used for infections of the lungs, throat, sinuses and ears, the urinary tract, the skin and the gut, and for some sexually transmitted infections such as chlamydia. Doctors may also prescribe it for other conditions based on current medical guidelines. Some bacteria are resistant to tetracyclines, so testing may be used to confirm it will work.
Whether you need an antibiotic depends on your symptoms and sometimes on test results. BC residents can speak with a BC-licensed doctor by phone through Avee Health about their symptoms and whether testing or a prescription is needed.
In Canada, doxycycline is authorized for infections caused by susceptible bacteria, including:
- Pneumonia and bronchitis
- Throat, tonsil, sinus and middle ear infections
- Urinary tract infections, including bladder and kidney infections
- Sexually transmitted infections, including chlamydia and gonorrhea of the urethra
- Skin infections such as impetigo, boils, cellulitis, abscesses, infected wounds and nail-fold infections
- Some gut infections
Some bacteria, including many strep and enterococcus strains, are resistant to tetracyclines. Treatment of sexually transmitted infections follows testing and current Canadian guidelines, so your prescriber may choose a different medicine or combination.
Doxycycline
Tetracycline antibiotic
antibiotics
Prescription required
Available
How Doxycycline Works
Doxycycline belongs to the tetracycline group of antibiotics. It stops bacteria from making the proteins they need to grow and multiply, which gives the immune system time to clear the infection. It does not work against viruses.
It is almost completely absorbed when taken by mouth, and food or milk do not significantly change how much is absorbed. Its half-life is about 18 hours, which is why it is usually taken once or twice a day.
Doxycycline binds to calcium and to metals such as iron, aluminum and magnesium. That is why antacids and some supplements reduce its effect, and why it can stain developing teeth.
Dosage Instructions of Doxycycline
Take doxycycline exactly as your prescriber directs. Canadian doxycycline product monographs give these usual adult doses:
- Most infections: 200 mg on the first day, then 100 mg once a day at the same time each day
- More severe infections: 200 mg a day for the whole course
- Chlamydia infections of the urethra, cervix or vagina: 100 mg twice a day, for the number of days your prescriber sets
How to take it safely: swallow each dose with a full glass of water while sitting or standing, and stay upright for 1 to 2 hours afterwards. Do not take it at bedtime. Taking it with or after a meal can reduce stomach upset.
Keep antacids, iron, calcium or magnesium supplements and bismuth subsalicylate (Pepto-Bismol) away from your doxycycline doses, as they reduce absorption. Ask your pharmacist how far apart to space them. No dose change is needed for kidney problems.
Finish the full course even if you feel better. Missed dose: take it as soon as you remember, unless it is almost time for the next dose. Do not take more than one dose at a time.
Storage Instructions
Store at room temperature, 15°C to 30°C, protected from light. Keep out of the reach and sight of children.
Side Effects of Doxycycline
The most common side effects affect the stomach and gut and rarely lead people to stop treatment. They include:
- Nausea, vomiting, loss of appetite and stomach pain
- Diarrhea
- Heartburn
Sun sensitivity that shows up as an exaggerated sunburn, vaginal yeast infections, headache, flushing and ringing in the ears can also occur.
Stop taking doxycycline and get medical help right away if you have:
- Pain or difficulty swallowing, or chest pain behind the breastbone
- A severe headache with nausea, vomiting, or blurred or double vision, which can be signs of raised pressure around the brain
- Watery or bloody diarrhea, with or without fever and stomach cramps, which can happen up to 2 months after treatment
- Trouble breathing, a fast heartbeat, swelling, itching, or a rash with blistering or peeling skin
- Swollen hands and feet with joint or muscle pain and a rash
- Yellow skin or eyes, or other signs of liver problems
Important Safety Information About Doxycycline
- Do not take doxycycline if you are allergic to it or any tetracycline, if you have myasthenia gravis, or if you take isotretinoin.
- Teeth: use during tooth development (late pregnancy, breastfeeding and childhood up to age 8) can permanently stain teeth yellow-grey-brown, even after short courses.
- Pregnancy and breastfeeding: it should not be used in pregnancy unless the benefit clearly outweighs the risk, and it is not recommended while breastfeeding. Stop taking it and tell your doctor if you become pregnant.
- Esophagus: it should not be used by people with a narrowing or blockage of the esophagus. Tell your prescriber if you have trouble swallowing.
- Sun: stop taking it at the first sign of skin redness after sun or UV exposure.
- Vision: raised pressure around the brain is rare but can cause lasting vision loss. Get prompt care for headache with vision changes.
- Lupus: doxycycline can worsen systemic lupus erythematosus. Tell your prescriber if you have it.
Drug Interactions
Tell your prescriber and pharmacist about everything you take, including vitamins and natural products. Important interactions include:
- Isotretinoin (such as Accutane): must not be taken with doxycycline, as both can raise pressure around the brain
- Antacids containing aluminum, calcium or magnesium, iron products and bismuth subsalicylate: reduce absorption
- Warfarin and other blood thinners taken by mouth: the anticoagulant dose may need to be lowered
- Alcohol, barbiturates, phenytoin and carbamazepine: can make doxycycline leave the body faster and work less well
- Penicillin antibiotics: combining them is generally avoided
- Birth control pills: may be less effective, so use another method during treatment and for 7 days after
- Medicines that can harm the liver: combining them should be avoided
Brands & DIN Number of Doxycycline
Brand Names
- Vibramycin
- Vibra-Tabs
Key Takeaways
- 1Doxycycline is a prescription tetracycline antibiotic used for a range of bacterial infections, including chest, skin, urinary and some sexually transmitted infections.
- 2It treats bacterial infections only, not colds, flu or other viral infections.
- 3Take each dose with a full glass of water, sitting or standing, and stay upright for 1 to 2 hours. Do not take it at bedtime.
- 4Keep antacids, iron, calcium, magnesium and Pepto-Bismol away from your doses.
- 5It makes skin more sensitive to the sun. Use sunscreen and avoid tanning beds.
- 6It is not used during pregnancy, while breastfeeding or in children under 8 unless other options will not work, because it can permanently stain developing teeth.
Frequently Asked Questions
Do I need a prescription for doxycycline in Canada, and how do I get it in BC?
Why can't I lie down after taking doxycycline?
Does doxycycline make you sensitive to the sun?
Can I drink alcohol while taking doxycycline?
Does doxycycline affect birth control?
Can I take doxycycline with milk or food?
How much does doxycycline cost in Canada?
When should I see a doctor about a possible bacterial infection?
Avee Editorial
Avee Editorial Team