Minocycline


Minocycline, sold under the brand name Minocin among others, is a tetracycline antibiotic medication used to treat a number of bacterial infections such as some occurring in certain forms of pneumonia. It is generally less preferred than the tetracycline doxycycline. Minocycline is also used for the treatment of acne and rheumatoid arthritis. It is taken by mouth or applied to the skin.
Common side effects include nausea, diarrhea, dizziness, allergic reactions, and kidney problems. Serious side effects may include anaphylaxis, a lupus-like syndrome, and easy sunburning. Use in the later part of pregnancy may harm the baby and safety during breastfeeding is unclear. It works by decreasing a bacterium's ability to make protein thus stopping its growth.
Minocycline was patented in 1961 and came into commercial use in 1971. It is available as a generic medication. In 2022, it was the 269th most commonly prescribed medication in the United States, with more than 900,000 prescriptions.

Medical uses

Acne

Minocycline and doxycycline are frequently used for the treatment of acne vulgaris. Minocycline is specifically indicated to treat inflammatory lesions of non-nodular moderate to severe acne vulgaris in people nine years of age and older. Both minocycline and doxycycline have similar levels of effectiveness and common adverse effects for acne, although doxycycline may have a slightly lower risk of adverse side effects. Both oral/systemic and more recently topical formulations of minocycline are available to treat acne.
Historically, oral minocycline has been an effective treatment for acne vulgaris. However, acne that is caused by antibiotic-resistant bacteria is a growing problem in many countries. In Europe and North America, a number of people with acne no longer respond well to treatment with tetracycline family antibiotics because their acne symptoms are caused by bacteria that are resistant to these antibiotics. In order to reduce resistance rates as well as increase the effectiveness of treatment, oral antibiotics should be generally combined with topical acne creams such as benzoyl peroxide or a retinoid. There have also been concerns about systemic minocycline having a variety of rare adverse effects in terms of its use to treat acne.
Oral minocycline is used to treat acne for up to 3 to 4months. Data beyond 3 to 4months are limited.

Other infections

Minocycline is also used for other skin infections such as methicillin-resistant Staphylococcus aureus.
Although minocycline's broader spectrum of activity, compared with other members of the group, includes activity against Neisseria meningitidis, its use for prophylaxis is no longer recommended because of side effects.
It may be used to treat certain strains of methicillin-resistant S. aureus infection and a disease caused by drug-resistant Acinetobacter spp.
A list of uses includes:
Minocycline has been reported to be effective in the eradication of UTIs and prostatitis. A 2013 Cochrane review identified and included two comparative clinical trials of minocycline for chronic bacterial prostatitis. For this condition, minocycline has been found to be equivalent or superior to doxycycline, equivalent to trimethoprim/sulfamethoxazole, and superior to the first-generation cephalosporin cephalexin. It was also equivalent to the fluoroquinolone ofloxacin in the treatment of chronic bacterial prostatitis caused by Ureaplasma urealyticum. Treatment durations of minocycline for chronic bacterial prostatitis have ranged from 2 to 4weeks.

Available forms

Minocycline is available in the form of 50 and 100mg oral capsules, among a variety of other formulations. The oral form of minocycline is usually taken twice daily, once every 12hours, although divided doses four times daily can also be employed. Extended-release oral forms are also available. A topical formulation is available as well.

Contraindications

The drug is contraindicated in people with known hypersensitivity to tetracycline antibiotics, as there is complete cross sensitivity in this group. It is also contraindicated in people with severe liver impairment and after the 16th week of pregnancy.

Side effects

Minocycline may cause upset stomach, diarrhea, dizziness, unsteadiness, drowsiness, mouth sores, migraines, and vomiting. It increases sensitivity to sunlight, and may affect the quality of sleep and rarely causes sleep disorders. It has also been linked to cases of lupus. Prolonged use of minocycline can lead to blue-gray staining of skin, fingernails, and scar tissue. This staining is not permanent, but can take a very long time for the skin color to return to normal; however, a muddy brown skin color in sun-exposed areas is usually permanent. Permanent blue discoloration of gums or teeth discoloration may also occur. Rare but serious side effects include fever, yellowing of the eyes or skin, stomach pain, sore throat, vision changes, and mental changes, including depersonalization.
Occasionally, minocycline therapy may result in autoimmune disorders such as drug-related lupus and autoimmune hepatitis, which usually occurs in men who also developed minocycline-induced lupus; however, women are more likely to develop minocycline-induced lupus. Significant or complete recovery occurs in most people who develop minocycline-induced autoimmune problems within a period of a few weeks to a year of cessation of minocycline therapy. Autoimmune problems emerge during chronic therapy, but can sometimes occur after only short courses of a couple of weeks of therapy. Drug reaction with eosinophilia and systemic symptoms syndrome can occur during the first few weeks of therapy with minocycline.
Minocycline, but not other tetracyclines, can cause vestibular disturbances, including symptoms of dizziness, ataxia, vertigo, and tinnitus. These effects are thought to be related to minocycline's greater penetration into the central nervous system. The vestibular side effects are much more common in women than in men, reportedly occurring in 50 to 70% of women receiving minocycline. However, other sources state that vestibular side effects occur in only 1 to 10% of patients. In any case, other studies have found that side effects occur more frequently in women than in men. Due to its vestibular side effects, minocycline has been said to be rarely used in female patients. Minocycline's vestibular side effects typically resolve after discontinuation of the drug.
Symptoms of an allergic reaction include rash, itching, swelling, severe dizziness, and trouble breathing. Minocycline has also been reported to very rarely cause idiopathic intracranial hypertension, a side effect also more common in female patients, potentially leading to permanent vision damage if not recognized early and treated.
Contrary to most other tetracycline antibiotics, minocycline may be used in those with kidney disease, but may aggravate systemic lupus erythematosus. It may also trigger or unmask autoimmune hepatitis.
Minocycline can cause the rare condition of secondary intracranial hypertension, which has initial symptoms of headache, visual disturbances, dizziness, vomiting, and confusion. Brain swelling and rheumatoid arthritis are rare side effects of minocycline in some people.
Minocycline, like most tetracyclines, becomes dangerous past its expiration date. While most prescription drugs lose potency after their expiration dates, tetracyclines are known to become toxic over time. Expired tetracyclines can cause serious damage to the kidney due to the formation of a degradation product, anhydro-4-epitetracycline. Minocycline's absorption is impaired if taken at the same time of day as calcium or iron supplements. Unlike some of the other tetracycline group antibiotics, it can be taken with calcium-rich foods such as milk, although this does reduce the absorption slightly.
Minocycline, like other tetracyclines, is associated with esophageal irritation and ulceration if insufficient fluids are taken with the drug before sleep.
A 2007 study suggested that minocycline harms amyotrophic lateral sclerosis patients. Patients on minocycline declined more rapidly than those on placebo. The mechanism of this side effect is unknown, although a hypothesis is that the drug exacerbated an autoimmune component of the primary disease. The effect does not seem to be dose-dependent because the patients on high doses did not do worse than those on the low doses.
Other possible rare side effects of minocycline include hyperpigmentation and hypersensitivity reactions, among others. It has been associated with more rare and serious adverse effects than other tetracyclines. Some of the rare adverse effects of minocycline may result in death. This has spurred interest in topical instead of systemic minocycline for treatment of acne.
Minocycline is another drug known to cause leukopenia.
Minocycine has shown thyroid toxicity in animals, including in rodents, mini pigs, dogs, and monkeys.
The use of minocycline to treat acne has been associated with skin and gut dysbiosis.

Overdose

Symptoms of minocycline overdose may include dizziness, nausea, and vomiting. There is no specific antidote for overdose of minocycline and treatment should be symptom-based and supportive. The drug is not removed by hemodialysis or peritoneal dialysis.