Minocycline and hepatitis

Critical data-based re-evaluation of minocycline as a putative specific microglia inhibitor

Minocycline, a second generation broad-spectrum antibiotic, has been frequently postulated to be a "microglia inhibitor." A considerable number of publications have used minocycline as a tool and concluded, after achieving a pharmacological effect, that the effect must be due to "inhibition" of microglia. It is, however, unclear how this "inhibition" is achieved at the molecular and cellular levels. Here, we weigh the evidence whether minocycline is indeed a bona fide microglia inhibitor and discuss how data generated with minocycline should be interpreted. GLIA 2016;64:1788-1794.

Safety of doxycycline and minocycline: a systematic review

OBJECTIVE

The goal of this review was to summarize the available literature covering the safety profiles of oral doxycycline and minocycline.

METHODS

Scientific literature published between 1966 and August 2003 was searched using the MEDLINE, EMBASE, and Biosis databases (search terms: minocycline or doxycycline, each paired with adverse reaction, adverse event, and side effect, and doxycycline or minocycline with the limits English language, human, and clinical trials). Safety information was collected from case reports and clinical trials. Adverse event (AE) rates in the United States were calculated by comparing data from the MedWatch AE reporting program used by the US Food and Drug Administration (FDA) with the number of new prescriptions dispensed for each drug from January 1998 to August 2003.

RESULTS

Between 1966 and 2003, a total of 130 and 333 AEs were published in case reports of doxycycline and minocycline, respectively. In 24 doxycycline clinical trials (n = 3833) and 11 minocycline trials (n = 788), the ranges in incidence of AEs were 0% to 61% and 11.7% to 83.3%, respectively. Gastrointestinal AEs were most common with doxycycline; central nervous system and gastrointestinal AEs were most common with minocycline. From January 1998 to August 2003, the FDA MedWatch data contained 628 events for doxycycline and 1099 events for minocycline reported in the United States. Approximately 47,630,000 doxycycline and 15,234,000 minocycline new prescriptions were dispensed in the United States during that period, yielding event rates of 13 per million for doxycycline and 72 per million for minocycline, based on FDA data.

CONCLUSIONS

Between 1998 and 2003, doxycycline was prescribed 3 times as often as minocycline. The incidence of AEs with either drug is very low, but doxycycline had fewer reported AEs. Although more head-to-head clinical trials are needed for a direct comparison of AE frequency, these preliminary data from separate reports suggest the possibility that AEs may be less likely with doxycycline than minocycline.

The risk of liver damage associated with minocycline: a comparative study

Using the General Practice Research Database, the authors performed (1) a cohort analysis comparing the incidence of liver dysfunction in new users of minocycline with new users of oxytetracycline/tetracycline and (2) a case control study assessing antibiotic exposure in new cases of liver dysfunction and controls without liver dysfunction. In new users, the incidence of liver dysfunction in those exposed to minocycline was 1.04 cases/10,000 exposed person months (EPM) and 0.69 cases/10,000 EPM in those exposed to oxytetracycline/tetracycline (relative risk 1.51 [CI95: 0.63, 3.65]). The risk in both groups was greatest in the first month of use. The adjusted odds ratio (ORadj) of liver dysfunction associated with exposure to minocycline compared with nonuse was 2.10 (CI95: 1.30, 3.40); for oxytetracycline/tetracycline, the ORadj was 1.46 (CI95: 0.81, 2.64); and for exposure to erythromycin, the ORadj was 1.64 (CI95: 0.71, 3.80). The authors thus support a weak association between the use of oral antibiotics and liver dysfunction in patients with acne. The risk associated with exposure to minocycline appears to be very small. The cohort analysis demonstrated that any risk associated with minocycline was not significantly greater than that associated with oxytetracycline/tetracycline exposure.

Liver damage associated with minocycline use in acne: a systematic review of the published literature and pharmacovigilance data

OBJECTIVE

Minocycline is an antibacterial drug used in the treatment of acne. Concern has been expressed over the possibility of severe adverse reactions to minocycline, including hepatitis. This study set out to identify and characterise reported cases of hepatotoxicity associated with the use of minocycline.

METHODS

A systematic review of the literature including a search of computerised databases and analysis of data from the Uppsala Monitoring Centre (WHO Collaborating Centre for International Drug Monitoring) was conducted. The review involved a search for original case reports involving liver damage in people using minocycline. Patients taking minocycline for reasons other than acne or those given intravenous minocycline were excluded. The search strategy involved an enquiry of computerised databases and a search for secondary references. Cases were then classified appropriately.

RESULTS

65 reported cases of hepatitis or liver damage in association with minocycline from either case reports or case series were identified from the literature review. 58% of cases occurred in females and 94% were aged under 40 years. For 20 case reports there was insufficient information to classify the type of event, but for the remaining 45, 2 types of hepatic reaction were recognised: autoimmune hepatitis associated with lupus-like symptoms occurring after a median duration of exposure to minocycline of 365 days in females (n = 20) and 730 days in males (n = 9), hypersensitivity reaction associated with eosinophilia and exfoliative dermatitis occurring within 35 days of therapy (n = 16). Reports to the WHO of hepatic adverse drug reactions associated with minocycline accounted for 6% (493) of all minocycline-related adverse drug reactions (8025). The pattern of distribution in relation to exposure demonstrated 2 groups, similar to that described by the case reports.

CONCLUSIONS

Severe cases of minocycline-associated hepatotoxicity appear to be a hypersensitivity reaction and occur within a few weeks of commencing therapy. An autoimmune hepatitis usually presents after exposure to minocycline of a year or more, is more common in women and is sometimes associated with lupus-like symptoms.

Minocycline-induced autoimmune syndromes: an overview

OBJECTIVE

To increase awareness of minocycline-induced autoimmune syndromes.

METHODS

Review of relevant publications from the American and European literature.

RESULTS

Four minocycline-induced syndromes have been described in 82 patients: serum sickness, drug-induced lupus, autoimmune hepatitis, and vasculitis. Aside from sporadic cases of serum sickness, all other syndromes occurred in patients treated for acne. Drug-induced lupus and hepatitis were by far the most common events (66 cases). Except for serum sickness, which presented shortly (mean, 16 days) after minocycline, the autoimmune syndromes manifested after protracted use (mean, 25.3 months). As expected, the patients with acne were young (mean, 19.7 years). The most frequent symptoms were arthralgia, followed by arthritis, fever, and rash (73, 45, 38, and 29 patients, respectively). Serologically, antinuclear antibodies were the most common finding (63 positive of 68 tests); perinuclear anti-neutrophilic cytoplasmic antibodies (pANCA), when assayed, were similarly frequent (20 of 24 tests). Surprisingly, anti-histone antibodies were uncommon, even among patients with drug-induced lupus (4 of 31 tests). The clinical and serological features of the separate syndromes may overlap. The diagnostic value of pANCA, as well as its possible role in minocycline-induced autoimmunity, are discussed.

CONCLUSIONS

Minocycline has the potential to evoke a variety of clinical and serological autoimmune expressions. The number of published reports may underestimate the frequency of this condition, which should be suspected and investigated in young patients with autoimmune manifestations.