Drug-induced lupus caused by very-low-dose hydralazine

Hydralazine-induced Lupus: Maintaining Vigilance with Increased Use in Patients with Heart Failure

OBJECTIVE

To review data concerning the incidence and danger of hydralazine-induced systemic lupus erythematosus (SLE) and review how best to monitor patients placed on chronic hydralazine therapy.

DATA SOURCES

Literature was sought utilizing PUBMED (1960 to present) and MEDLINE (1966 to present). Search terms included hydralazine, drug-induced systemic lupus erythematosus, congestive heart failure, and antinuclear antibody.

DATA SYNTHESIS

A major adverse effect of hydralazine therapy is drug-induced SLE. An evaluation of case reports and review of the literature was undertaken to determine the significance of this major adverse effect and stress the importance of close monitoring of patients placed on chronic hydralazine therapy for heart failure. Risk factors are discussed including high daily doses, slow acetylator and HLA-DRw4 phenotypes, therapy longer than 3 months, and female gender.

CONCLUSIONS

Following the publication of A-HeFT, an increase in the amount of hydralazine prescribed in patients with heart failure has been noted. Patients should be closely monitored when initiating hydralazine and during chronic therapy. Although dose limitation of hydralazine reduces risk, low doses are well documented to be associated with SLE. A baseline antinuclear antibody level should be determined on initiation of hydralazine, but it is not recommended to regularly check antinuclear antibody levels because a positive result does not necessarily indicate SLE is present. Patients should be monitored at each visit for signs and symptoms of SLE, and, if any signs and symptoms of the syndrome develop while the patient is on hydralazine therapy, the drug should be discontinued immediately because complications from the syndrome can be potentially fatal.

Drug-induced rheumatic syndromes. Diagnosis, clinical features and management

In order to avoid inappropriate therapy and prolonged morbidity, it is important to recognise when a patient's rheumatic complaints are due to drugs. However, this is often difficult because of the large number of drugs that have been implicated and the diversity of clinical presentations. Arthropathy may be seen with several different syndromes, including drug-induced lupus erythematosus (DILE), serum sickness and gout. The most widely reported of these is DILE, which usually develops after some months or even years of drug therapy. While many authors do not specifically require their presence for the diagnosis of DILE, antinuclear antibodies have been detected in the great majority of reported patients with DILE, whatever the causative drug. In contrast, patients who develop arthropathy soon after commencing a drug rarely have antinuclear antibodies and appear to be distinct from patients with DILE. Apart from arthropathy, a number of other syndromes that appear to have an immunological basis may be induced by drugs. Cutaneous vasculitis is not uncommon and drugs are frequently considered to be the aetiological factor. Whether drugs may cause larger vessel systemic vasculitis is less certain. Rarely, polymyositis and scleroderma-like syndromes have been associated with drug therapy. Corticosteroid-induced osteoporosis is a complication of all the corticosteroid preparations that are widely used at present. However, the development of deflazacort, a so-called 'bone-sparing' steroid, has raised the possibility that the effect of corticosteroids on bone may be separable, at least in part, from the other actions of these drugs. Data have been conflicting with regard to whether there is a 'safe' dose of corticosteroid. Similarly, it is unclear whether prophylactic therapy with agents such as calcium, fluoride and vitamin D is beneficial. Nonetheless, recent findings suggest that approaches will be developed to minimise the risk of osteoporosis in patients who require corticosteroids. There are a number of other ways in which drugs may affect bones. Osteomalacia is a well-known but uncommon complication of treatment with anticonvulsants and occasionally other drugs. The mechanism probably relates to the induction of hepatic enzymes and the consequent increased metabolism of vitamin D in patients with borderline levels initially. Osteosclerosis may also result from drug therapy; usually with fluoride or retinol (vitamin A) and its analogues. With continued research, the true spectrum of drug-induced rheumatic syndromes should become more clearly defined.(ABSTRACT TRUNCATED AT 400 WORDS)