Minocyclines 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.The use of minocycline in acne vulgaris has been associated with skin and gut dysbiosis (see antibiotic misuse). Interactions
The combination of minocycline with dairy, antacids, calcium and magnesium supplements, iron products, laxatives containing magnesium, or bile acid sequestrants may decrease minocyclines effectiveness by forming chelates. Combining it with isotretinoin, acitretin or other retinoids can increase the risk for intracranial hypertension. Minocycline significantly reduces concentrations of the anti-HIV drug atazanavir in the body. Pharmacology
Mechanism of action
Pharmacokinetics
Minocycline is quickly and nearly completely absorbed from the upper part of the small intestine. Taking it together with food, including milk, has no relevant influence on resorption. It reaches highest blood plasma concentrations after one to two hours and has a plasma protein binding of 70–75%.
The substance penetrates into almost all tissues; very high concentrations are found in the gallbladder and liver. It crosses the blood–brain barrier better than doxycycline and other tetracyclines, reaching therapeutically relevant concentrations in the cerebrospinal fluid and also in inflamed meninges.Minocycline is inactivated by metabolization in the liver to about 50%. The rest is predominantly excreted into the gut (in part via the gallbladder, in part directly from blood vessels) and eliminated via the feces. About 10–15% are eliminated via the kidneys. The biological half-life is 14–22 (11–26) hours in healthy people, up to 30 hours in those with kidney failure, and significantly longer in those with liver disease. Chemistry
The drug is used in form of minocycline hydrochloride dihydrate, which is sparingly soluble in water and slightly soluble in ethanol. Minocycline reacts acidic in aqueous solution. History
Minocycline was patented in 1961 and came into commercial use in 1971. A topical foam for treatment of acne was approved in 2019. Society and culture
Trade names
Many forms of minocycline are no longer covered by patent, so it is marketed under a variety of trade names:

Minomycin
Minostad (in Europe, for the treatment of acne)
Akamin
Minocin
Minoderm
Cyclimycin
Arestin (1-mg doses administered locally into periodontal pockets, after scaling and root planing, for treatment of periodontal disease.)