Minocycline belongs to the class of medications called tetracycline antibiotics. It is used to treat infections caused by certain types of bacteria. It is most commonly used to treat certain types of skin infections, urinary tract infections, gallbladder infections, and respiratory tract infections such as bronchitis, pneumonia, and sinusitis.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Do not take this medication if you:

• are allergic to minocycline or any ingredients of the medication
• are allergic to other tetracycline antibiotics (e.g., doxycycline, tetracycline)
• are pregnant
• are breast-feeding
• are experiencing kidney failure
• have severe liver disease
• have myasthenia gravis

Do not give this medication to children less than 13 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• cramps or burning of the stomach
• diarrhea
• dizziness
• itching of the rectal or genital areas
• lightheadedness
• loss of appetite
• nausea
• sore mouth or tongue
• spinning sensation
• unusual hair loss or thinning
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal pain
• bulging soft spot on head of infants
• headache
• hearing changes
• increased sensitivity of the skin to sunlight
• joint pain, stiffness, or swelling
• nail, skin, or tooth discolouration
• signs of irritation or ulcers in the esophagus (e.g., difficulty or pain with swallowing, sore throat, hoarse voice, heartburn, nausea)
• signs of kidney problems (e.g., decreased urination, nausea, vomiting, fluid retention, fatigue)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• tingling or numbness of the hands or feet
• vaginal itching or discharge

Stop taking the medication and seek immediate medical attention if any of the following occur:

• severe diarrhea (may contain blood or mucus)
• symptoms of a serious skin reaction (such as a severe blistering skin rash that causes the skin to peel or fall off; fever; or bloodshot eyes)
• symptoms of a severe allergic reaction (such as hives, difficulty breathing, and swelling of the face or throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Bacterial resistance: Misuse of an antibiotic such as doxycycline may lead to the growth of resistant bacteria that will not be killed by the antibiotic. If this happens, the antibiotic may not work for you in the future. Although you may begin to feel better when you first start taking doxycycline, you need to continue taking the medication exactly as directed to finish ridding your body of the infection and to prevent resistant bacteria from taking hold. Do not take doxycycline or other antibiotics to treat a viral infection such as the common cold; antibiotics do not kill viruses, and using them to treat viral infections can lead to the growth of resistant bacteria.

Birth control pills: When you use birth control pills at the same time as minocycline, they may be less effective, and you may experience an increased risk of breakthrough bleeding. Your doctor may advise that you use a second form of birth control while taking this medication.

Diarrhea: Minocycline may infrequently cause a condition called pseudomembranous colitis (serious diarrhea caused by antibiotics). If you develop severe diarrhea after starting this medication, even several weeks after treatment, contact your doctor as soon as possible.

Discolouration of teeth: The use of minocycline during tooth development (from the last trimester of pregnancy to the age of 13 years) may cause permanent discolouration of the teeth (yellow-grey-brown). Though more commonly associated with long-term use of tetracyclines, this effect has also been known to occur after taking the medication for a short time. For this reason, minocycline should not be used by children 13 years old or younger unless other medications are unlikely to be effective or can't be used.

Drowsiness/reduced alertness: People who take minocycline may experience headaches, lightheadedness, dizziness, or loss of balance. Decreased hearing has been reported rarely by those who take this medication. These symptoms may disappear during therapy and usually disappear rapidly when the medication is stopped. Avoid activities requiring alertness, such as driving vehicles or using hazardous machinery if the medication affects you in this way.

Galactose intolerance/glucose malabsorption: Some brands of minocycline contain lactose. If you have lactose or galactose intolerance you should not take these medications.

Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Minocycline may reduce liver function and can cause liver failure. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Medical conditions: If you have autoimmune disease or lupus, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Overgrowth of organisms: The use of antibiotics may occasionally result in an overgrowth of organisms not killed by medication. This can cause conditions such as yeast infections to occur. You may be able to prevent yeast infections by eating yogurt daily while taking minocycline.

Sun sensitivity: An exaggerated sunburn reaction may occur for some people taking minocycline. If skin redness appears, stop taking the medication and check with your doctor.

Pregnancy: This medication should not be used during pregnancy. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are breast-feeding and are taking minocycline, it may affect your baby. Do not breast-feed while taking this medication.

Children: Minocycline is not recommended for use by children younger than 13 years of age.

There may be an interaction between minocycline and any of the following:

• antacids containing aluminum, calcium, or magnesium
• BCG
• birth control pills
• bismuth subsalicylate
• calcium supplements
• cholera vaccine
• cholestyramine
• colestipol
• iron and iron-containing vitamins
• lanthanum
• lithium
• methotrexate
• multivitamins
• penicillins (e.g., penicillin V, amoxicillin, ampicillin)
• quinapril
• retinoic acid derivatives (e.g., acitretin, tretinoin)
• sodium bicarbonate or citrate
• sodium picosulfate
• sucralfate
• sulfonylureas (e.g., glyburide, gliclazide)
• zinc supplements
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.