Minocycline Hydrochloride: The Emerging Evidence of Its Therapeutic Value in Complicated Bacterial Infections

In order to address increasing antimicrobial resistance issues in combination with few new antimicrobial agents, minocycline has renewed interest for new uses in resistant, serious infections. Minocycline is a broad-spectrum antimicrobial with activity against Gram-positive and -negative bacteria, including aerobes and anaerobes as well as Mycoplasma, Chlamydia, Rickettsia, Nocardia, Legionella, and various spirochetes. Minocycline has many favorable attributes including good pharmacokinetic profile, high tissue penetration, intravenous and oral preparation, and negligible dose adjustments for patients with renal and hepatic dysfunction. In case studies, minocycline does display efficacy in the treatment of S. aureus skin and soft tissue infections, and has been used successfully in the management of patients with S. aureus endocarditis, including MRSA. Minocycline-rifampin impregnated catheters are efficacious in both preventing colonization of catheters as well as preventing bloodstream infections associated with catheter use. In Gram-negative infections, case reports have described the successful use of minocycline for pneumonia, hospital-associated and ventilator-associated type, and wound infections due to A. baumanii and S. maltophilia. In sexually transmitted infections, minocycline may be an attractive alternative to doxycycline in the treatment of nongonococcal urethritis and mucopurulent cervicitis. It has demonstrated efficacy in the treatment of neurosyphilis in those patients with penicillin allergies. As bacterial resistance issues continue to worsen, additional clinical evidence for the use of minocycline in complicated bacterial infections may arise, further integrating its place in therapy for these infections. Most of this evidence will likely come from case report, cohort, or observational studies since prospective randomized trials with minocycline will be difficult to perform.