Minocycline (Oral)

Minocycline is an antibiotic used to treat a variety of bacterial infections, including acne.

Overview

Minocycline is a type of antibiotic which is used to treat a variety of severe or persistent bacterial infections. It can treat respiratory tract infections such as pneumonia, infections of the skin, eyes, lymphatic system, genitals, and urinary systems, and certain infections which are spread by infected animals, mites, lice, and ticks. It can also treat persistent acne when administered in its extended-release tablet form.

Sometimes minocycline is used to treat very serious infections such as plague, tularemia, and anthrax. In instances where patients cannot be treated with penicillin, perhaps due to allergy, it may be used to treat some types of food poisoning. It can also work to remove bacteria from the nose and throat which may cause meningitis, even if there is no infection present.

Antibiotics like minocycline work by preventing the growth and spread of bacteria. When used to treat acne, not only does it kill the bacteria which infects the pores and causes pimples, but it also decreases the amount of oil in the skin which causes acne. Minocycline will not treat colds or flu, since these are viral infections and are unaffected by antibiotics.

Minocycline is only available with a doctor's prescription. The oral version of the medicine is available in a range of dosage forms and brand names, including:

  • Extended release capsules:
  •  Cleeravue-M
  • Dynacin
  • Minocin
  • Ximino
  • Tablets
  • Myrac
  • Solodyn

Conditions Treated?

  • Acne
  • Bacterial infections

Type Of Medicine?

  • Tetracycline antibiotic

Side Effects

As well as its needed effects, minocycline can cause a variety of unwanted side effects. While it is unlikely that all of these side effects will occur, patients should still familiarize themselves with them so they can recognize the appropriate time to visit a doctor.

The following side effects associated with minocycline are serious, and require immediate medical attention:

  • Black, tarry stools
  • Blood in urine or stools
  • Diarrhea
  • Nausea or vomiting
  • Severe stomach pain
  • Upper right abdominal or stomach pain
  • Joint or muscle pain
  • Chest pain, sometimes moving to left arm, neck, or shoulder
  • Fast heartbeat
  • Troubled breathing
  • Bulging soft stop on the head of an infant
  • Yellow eyes or skin
  • Unusual bleeding or bruising
  • Blistering, peeling, or loosening skin
  • Itching, skin rash, or hives
  • Large, hive-like swellings on face, lips, tongue, throat, hands, feet, or genitals
  • Skin lesions, sometimes with purple center
  • Sores, ulcers, or white spots on mouth or lips
  • Eye pain
  • Blurred vision
  • Double vision
  • Dizziness or lightheadedness
  • Severe headache
  • Confusion
  • General feeling of illness or discomfort
  • General tiredness and weakness
  • Loss of appetite

The following side effects are less serious and only require medical attention if they become very severe or persistent. If you have questions about them or they become very bothersome, consult your doctor. You may find that they dissipate once your body adjusts to treatment.

  • Ringing, buzzing, or other unexplained noise in ears
  • Hearing loss
  • Sleepiness or unusual drowsiness
  • Difficulty moving
  • Muscle stiffness
  • Hives or welts
  • Redness of the skin
  • Increased skin sensitivity to sunlight
  • Severe sunburn
  • Bloating
  • Indigestion
  • Discoloration of teeth

These may not be exhaustive lists of all the side effects that could occur during treatment with minocycline. If you notice others not listed here, always consult your doctor. You may also want to report new side effects to the FDA, or your doctor may do this on your behalf.

Dosage

The amount of minocycline you take will vary depending on the condition being treated, the dosage form prescribed to you, and other factors personal to you and your medical history. Always follow your doctor's dosage instructions over any other average or recommended dosages.

It is also very important to take minocycline for as long as directed by your doctor, even if your symptoms improve and you feel better sooner. Stopping antibiotics before the end of a full course could result in the infection returning, and it may become more difficult to treat.

For the treatment of infection, most adults take 200 mg initially, followed by 100 mg every 12 hours. However, some adults may start with 100 mg followed by 50 mg taken four times each day. For children aged 8 years and older, the dose of minocycline is determined by their body weight. Initially, children usually take 4 mg per kilogram of body weight, followed by 2 mg per kilogram of body weight every 12 hours. Children under the age of 8 are not recommended to take minocycline.

For the treatment of acne, most adults and children aged 12 years and older have their dose determined by their body weight. Usually, the dose is 1 mg of minocycline per kilogram of body weight. This is taken once each day for 12 weeks. For children aged between 8 and 12 years, the dose must be determined by a doctor. For children under 8, the drug is not recommended.

How to take oral minocycline

Minocycline capsules and tablets should be swallowed whole, without crushing, chewing, or breaking them. You should take them with a full glass of water to minimize stomach irritation. You can take the medicine either with or without food.

If patients miss a dose of minocycline, they should take it as soon as they remember. However, if it is almost time for the next dose when they remember, they should simply skip the missed dose and continue with their usual dosing schedule. Never double doses of minocycline as this could increase the risk of harmful side effects.

Interactions

It is very important to tell your doctor about all the other medicines you take before you start taking minocycline. This is because there is a risk of serious drug interactions which could either increase the risk of certain side effects, cause secondary health issues, or result in some of your medicines being less effective.

Mention all prescription and over-the-counter (OTC) medicines, as well as any herbal supplements or vitamins that you take. Always check with your doctor before taking new OTC medicines once you have started your treatment with minocycline.

It is particularly important to tell your doctor that you are taking the following types of medicines:

  • Anticoagulants (also known as blood thinners), such as warfarin

    Ergot-type medicines, such as:

  •  Bromocriptine
  •  Cabergoline
  •  Dihydroergotamine
  •  Ergoloid mesylates
  •  Ergonovine
  •  Ergotamine
  • Methylergonovine
  • Penicillin
  • Isotretinoin (or recent use)

It's important to note that minocycline can make some oral contraceptives less effective. If you rely solely on oral contraceptives, you may need to use an additional or alternative form of birth control to prevent pregnancy during treatment with minocycline. Discuss this with your doctor.

The following medicines can make minocycline less effective than usual:

  • Antacids containing aluminum, calcium, or zinc
  • Laxatives containing magnesium
  • Calcium supplements
  • Iron products and supplements
  • Zinc products and supplements

In order to ensure minocycline is effective, you will need to take these medicines a certain number of hours before or after minocycline. Antacids, calcium supplements, and laxatives containing magnesium should be consumed at least two hours before or six hours after minocycline. Products which contain iron should be taken either two hours before or four hours after minocycline. Products which contain zinc should be taken either two hours before or after minocycline.

Sometimes dairy products can interfere with the way minocycline is absorbed by the body and may make it less effective. Discuss with your doctor whether you need to avoid dairy during treatment.

Warnings

Interactions with other medical conditions

Make sure your doctor has your full medical history. They should know about all the conditions you currently suffer from, as well as those you have suffered from in the past. This is so that they can check whether minocycline is safe for you.

The following medical problems may be worsened by minocycline:

  • Increased pressure in head
  • Infection of any type
  • Diarrhea
  • Liver disease

Kidney disease can affect the way that minocycline is processed by the body. Essentially, if the kidneys do not function as normal, they will not remove minocycline from the body as quickly as usual. If the drug remains in the system for longer, its effects may be more potent, and patients may be at risk of severe side effects. Depending on the severity of your kidney disease, your doctor may avoid prescribing minocycline altogether, or they may administer lower initial doses and monitor you to see how the drug affects you.

Risk of lightheadedness

Sometimes minocycline can cause patients to feel lightheaded or dizzy. You should never drive or operate machinery if you do notice these side effects. When you first start taking minocycline, avoid driving or operating machinery until you know how the medicine affects you.

Increased skin sensitivity to sunlight

Minocycline can make the skin more sensitive to sunlight, which could lead to very severe sunburn. Use sunscreen and wear sunglasses and protective clothing whenever you will be exposed to the sun. It may be safest to completely avoid prolonged sun exposure where possible. Sunscreen should be a minimum of SPF 15, but this should be much higher in those with fair skin. You should also use an SPF 15 sunblock lipstick on the lips. Avoid sun lamps or tanning booths during treatment with minocycline.

Darkened skin

Sometimes minocycline can cause the color of skin, eyes, teeth, gums, nails, and scars to darken. This is not usually something that requires treatment, but if you are concerned about it consult your doctor.

Diarrhea

Minocycline may cause diarrhea and in some cases, it can be very severe. Diarrhea may occur for up to two months or more after treatment with minocycline stops. If you find that diarrhea is very severe or persistent, consult your doctor. Do not take medicines to treat diarrhea without first checking that it is safe to so do with your doctor, because some diarrhea treatments may simply make the diarrhea worse or prolong it.

Liver problems

Minocycline can cause serious liver problems. Consult your doctor immediately if you experience pale stools, dark urine, appetite loss, nausea or vomiting, yellow eyes or skin, or pain in the upper stomach area.

Vision problems

In rare instances minocycline can cause increased pressure in the brain, which may lead to permanent loss of vision. Severe headaches and blurred or changed vision should be reported to a doctor immediately.

Autoimmune problems

Fever, rash, extreme tiredness, and joint pain are signs of an autoimmune syndrome in which the body attacks itself, which can occur after treatment with minocycline. If you notice these symptoms, consult your doctor immediately.

Keep all appointments

Your doctor will want to check the progress of your treatment intermittently. This is to assess how successfully minocycline is working, and to check for any adverse effects. Sometimes blood tests or urine tests may be requested. It is very important that you keep all appointments with your doctor.

If you notice that your symptoms don't improve by the end of your course of treatment, or after 12 weeks if undergoing treatment for acne, consult your doctor.

Allergy

Tell your doctor if you have had an allergic reaction to minocycline in the past, or to any of the following antibiotics:

  • Tetracycline
  • Doxycycline
  • Demeclocycline

You should also make sure your doctor knows about any drug, food, animal, pollen, dye, or chemical allergies you suffer from so that they can check that you are not allergic to any of the ingredients in minocycline capsules or tablets.

If you notice any of the following symptoms of allergy while taking minocycline, tell your doctor right away or seek emergency medical care:

  • Itching, rash, or hives
  • Swellings of the face, lips, tongue, or throat
  • Cough or wheezing
  • Breathing problems

Pediatric use

There is evidence of minocycline causing discoloration of the teeth and slowed rate of bone growth when it is administered to children under 8 years old. For this reason, use of the drug in this age range is not recommended. However, depending on the nature and severity of the condition being treated, and whether alternative treatments are available or successful, doctors may continue to prescribe minocycline. In these instances, the benefits of the drug must far outweigh potential risks, and doctors will determine an appropriate dose on a case by case basis.

Geriatric use

Minocycline appears to be just as effective in the treatment of infection in elderly adults as it is in treating younger adults. However, elderly patients are more likely to have age-related liver disease, kidney disease, or heart problems, which may result in a higher risk of side effects or complications. Doctors may administer lower doses of the drug initially and monitor for adverse effects.

Birth control

Minocycline can make oral contraceptives less effective. Patients should use alternative or additional birth control throughout treatment to prevent pregnancy.

Pregnancy and breastfeeding

Minocycline may cause fetal harm when taken by pregnant women during any stage of pregnancy. Tell your doctor if there is a chance that you could be pregnant before taking minocycline. If you become pregnant while taking the drug, contact your doctor immediately.

It is also important to note that birth defects could occur in a fetus which is conceived while the father is taking minocycline. If a pregnancy occurs during these circumstances, consult your doctor immediately.

There is conflicting evidence as to whether minocycline is safe for nursing infants when it is taken by women who are breastfeeding. Discuss the potential risks with your doctor. Short term use may be acceptable, but it may simply be safer to avoid breastfeeding while taking minocycline if possible.

Risk of unusual test results

Minocycline may affect the accuracy of certain medical tests and cause unusual results. Tell every doctor you see that you are taking minocycline, particularly if they request medical tests.

Storage

Minocycline should be stored in the container in which it was provided to you. Keep it at room temperature and away from direct light, heat, or moisture and do not allow it to freeze. Always keep it out of sight and reach of children.

If you have unused or expired minocycline, ask your healthcare provider how to dispose of it. Do not keep it. Use a medicine take-back program rather than simply throwing the medicine in the trash or flushing it down the toilet where it may come to harm other people or the environment. Pharmacies, healthcare providers, and garbage or trash recycling departments often offer medicine take-back schemes.

Summary

Minocycline is an antibiotic used to treat a variety of bacterial infections, including pneumonia, urinary infections, and acne. It can also be used for very serious infections such as plague or anthrax or to remove the bacteria in the nose and throat which may cause meningitis. The drug is available in tablet and capsule forms.

Some patients may experience an unexplained buzzing or ringing in their ears, sleepiness, drowsiness, or lightheadedness, increased sensitivity to sunlight, indigestion and bloating, and tooth discoloration while taking minocycline. These are minor side effects which only require medical attention if they become very severe or persistent, or you feel particularly concerned by them.

If patients notice unusual colored stools, nausea or vomiting, abdominal pain, chest pain, jaundice, blistering, peeling, or lesions on the skin, eye pain, blurred vision, severe headache, confusion, or extreme tiredness, they should consult a doctor right away. These are all serious side effects which could be very dangerous if left untreated.

The amount of minocycline a patient takes will depend on factors personal to them, such as their age, their medical history, and their weight. Recommended dosages also vary between brands and dosage forms of minocycline. Always follow your doctor's instructions closely. You may find that your dose changes depending on how successfully the drug is working. Be sure to finish your full course of treatment, even if you notice your symptoms improve. If you stop an antibiotic before the end of its course, the infection may come back and it may be harder to treat in future.

Patients should tell their doctor about all the other prescription and non-prescription medicines and supplements that they take, particularly anticoagulants, ergot-type medicines, penicillin and isotretinoin. They should also take care if they take supplements, medicines, or products which contain aluminium, calcium, magnesium, or zinc, since these substances can make minocycline less effective. Doctors will advise you to take these types of medicines a number of hours before or after taking minocycline.

Minocycline can make oral contraceptives less effective, and patients must therefore use alternative contraception to avoid pregnancy during treatment. This drug is not suitable for use during pregnancy due to risks to fetal health. Furthermore, minocycline may cause birth defects if pregnancy occurs either when the mother or father is taking the drug at the time of conception.

While minocycline appears to be safe for children over the age of 8, in children under 8 it can cause tooth discoloration and slowed bone growth. However, doctors may still prescribe it to this age group if there are no other successful treatments available and the benefits of the drug outweigh risks.