Chronic intoxication by doxycycline use for more than 12 years

Drug-Induced Liver Injury Due to Doxycycline: A Case Report and Review of Literature

Antibiotics are among the most common causes of drug-induced liver injury worldwide. Amoxicillin/clavulanic acid and nitrofurantoin are the most common culprits while tetracyclines are a rare cause of liver injury. Among tetracyclines, minocycline has been reported more frequently than doxycycline, which is an extremely rare cause of drug-induced liver injury. We present a healthy 28-year-old male patient from rural United States who was taking doxycycline for Lyme disease. After five days of therapy, he developed nausea, vomiting, fatigue, and significant transaminitis consistent with a hepatocellular pattern of liver injury. After a thorough workup which ruled out other causes such as infection, autoimmune diseases, liver malignancy, and vascular, structural, and metabolic disorders, his liver injury was attributed to doxycycline. We reached the diagnosis also by demonstrating a consistent temporal association between doxycycline intake and liver injury and the patient recovered completely with the cessation of doxycycline. Recognition of doxycycline as a cause of drug-induced liver injury should be considered in patients utilizing this antibiotic. Doxycycline, unlike minocycline, has a short latency period. Early recognition and discontinuation of doxycycline in our patient resulted in the complete resolution of symptoms and transaminitis preventing further morbidity and mortality.

Doxycycline-Associated Hyperpigmentation: A Case Report and Literature Review

Drug-induced hyperpigmentation is an adverse cutaneous effect; it has been associated with several systemic medications. A healthy 40-year-old man developed facial and dorsal hand hyperpigmentation within two weeks of beginning doxycycline monohydrate 100 milligrams twice daily for acne. Skin pigmentation significantly diminished at a follow-up evaluation two months after discontinuing the medication. Doxycycline-associated skin hyperpigmentation, albeit uncommon, has been described in 18 patients in the literature, including our patient. The demographics included 13 males and five females ranging in age from 11 to 87 years; eight of the patients were less than 50 years old and ten of the patients were over 60 years old. Doxycycline-associated hyperpigmentation frequently occurs on the face and can occur at the site of a previous scar. In most cases, doxycycline was discontinued with the resolution of hyperpigmentation.

Doxycycline for malaria chemoprophylaxis and treatment: report from the CDC expert meeting on malaria chemoprophylaxis

Doxycycline, a synthetically derived tetracycline, is a partially efficacious causal prophylactic (liver stage of Plasmodium) drug and a slow acting blood schizontocidal agent highly effective for the prevention of malaria. When used in conjunction with a fast acting schizontocidal agent, it is also highly effective for malaria treatment. Doxycycline is especially useful as a prophylaxis in areas with chloroquine and multidrug-resistant Plasmodium falciparum malaria. Although not recommended for pregnant women and children < 8 years of age, severe adverse events are rarely reported for doxycycline. This report examines the evidence behind current recommendations for the use of doxycycline for malaria and summarizes the available literature on its safety and tolerability.

Association between tetracycline or doxycycline and hepatotoxicity: a population based case-control study

BACKGROUND AND OBJECTIVE

An FDA Working Group, along with representatives of PhRMA and the American Association for the Study of Liver Diseases, as well as the Institute of Medicine Report 'To Err is Human: Building a Safer Health Care System' have suggested that post-marketing drug surveillance is a important method to decrease adverse drug events. While tetracyclines are known to cause hepatotoxicity, no post-marketing drug surveillance studies have examined the risk of developing hepatotoxicity with tetracyclines. Therefore, the objective of this study is to determine the difference in risk of hepatotoxicity in patients receiving doxycycline or tetracycline using California Medicaid claims.

METHODS

This study used a retrospective, matched case-control study using California Medicaid claims data. The cases were defined as recipients who had at least one diagnosis of hepatotoxicity any time from 1 July 1999 to 31 December 2001. One control was identified for each case, matched on age, gender and race. Logistic regression was used to determine the adjusted odds ratio (OR) and 95% confidence intervals for current users and past users of tetracycline and doxycycline. Covariates controlled for in the analysis were age, use of other hepatotoxic drugs, renal dysfunction, pregnancy, and alcohol or illicit drug use.

RESULTS

A total of 3377 cases of hepatotoxicity were identified. Current users and past users of tetracycline had a statistically significant increased risk of developing hepatotoxicity (current use OR 3.70, 95% CI 1.19-11.45; past use OR 2.72, 95% CI 1.26-5.85). Current users or past users of doxycycline did not have an increased risk of developing hepatotoxicity (current use OR 1.49, 95% CI 0.61-3.62; past use OR 1.74, 95% CI 0.99-3.06). Tetracycline was commonly used for acne, acute bronchitis and upper respiratory infections. Doxycycline was commonly used for acute bronchitis, vaginitis and acne.

DISCUSSION AND CONCLUSION

Doxycycline was potentially less hepatotoxic than tetracycline. Doxycycline could potentially be a safe substitute for tetracycline, when appropriate.

Cutaneous hyperpigmentation induced by doxycycline: histochemical and ultrastructural examination, laser microprobe mass analysis, and cathodoluminescence

Skin hyperpigmentation induced by minocycline is a well-recognized side effect of minocycline but has rarely been reported for other tetracyclines. Based on a previously reported unusual case of chronic doxycycline abuse in a psychotic patient, we have investigated the nature of the observed pigment changes in the same patient. Histopathologic investigation of lesional skin by light microscopy disclosed hyperpigmentation of the basal keratinocytes and pigment-laden histiocytes in the dermis and subcutaneous fat. Only the pigment in the histiocytes of the upper dermis was reactive for Fontana Masson stain and could be bleached by hydrogen peroxide. The other histiocytes contained iron and calcium deposits as shown by von Kossa and Perls staining as well as by laser microprobe mass analysis. Ultrastructurally, these histiocytes contained amorphous material within the cytoplasm and stored in lysosomal structures. Comparative cathodoluminescence disclosed the presence of doxycycline in affected skin by means of overlapping emission spectra between the patient's skin and pure doxycycline. Taken together, the histomorphologic and ultrastructural changes induced by doxycycline shared several features with cutaneous hyperpigmentation caused by minocycline. Our biophysical findings further suggest a direct deposition of doxycycline, probably chelated with iron and/or calcium, within the lesional skin. Based on the presented unique case and the reviewed literature, only suprapharmacologic doses of doxycycline may be sufficient to cause such pigment changes.