Ophthalmologic safety of long-term hydroxychloroquine treatment

Hydroxychloroquine in the treatment of rheumatoid arthritis

One hundred eight patients with rheumatoid arthritis received hydroxychloroquine for six to 24 months and were studied retrospectively to examine long-term efficacy and predictors of a favorable response to the drug. Response was classified in terms of reduction of active joint count and morning stiffness. Thirteen patients (12 percent) showed a complete remission. Fifteen patients (14 percent) had a 75 percent or greater response. Forty patients (37 percent) had a 30 to 75 percent response. Thirty-two (30 percent) had no response. Toxicity occurred in eight patients (7 percent) before clinical efficacy could be assessed. Seven of the 68 with response had a flare of disease after initial improvement. Of multiple clinical and laboratory parameters tested, only a stronger baseline grip strength was found to be statistically significant (p less than 0.001) in predicting a favorable response. Thus, hydroxychloroquine is an effective drug in the management of rheumatoid arthritis.

Ophthalmologic safety of long-term hydroxychloroquine sulfate treatment

The fear of retinal toxicity has been a major factor limiting the use of chloroquine and hydroxychloroquine. Patients reported to develop retinal toxicity with visual loss usually took daily dosages higher than those currently in use. Toxicity with low dosages (for example, 250 mg per day chloroquine or 400 mg per day hydroxychloroquine) usually reveals pigment abnormalities; associated loss of vision is rare. When 99 patients treated with hydroxychloroquine for more than one year were studied prospectively, four patients showed evidence of retinal toxicity; none developed visual loss, and all abnormalities were completely reversible after drug discontinuation. All persons receiving antimalarials should be evaluated by an ophthalmologist at baseline and every six months thereafter. Funduscopic examinations and visual field testing with a red object must be included. Although this protocol may detect abnormalities that are not drug related, no loss of vision has developed in patients so monitored.

Ophthalmologic considerations and testing in patients receiving long-term antimalarial therapy

We do not as yet understand all the mechanisms involved in retinal toxicity. Such risk is lower with hydroxychloroquine than with chloroquine. The risk of true retinopathy rises with duration of therapy. The benefit/risk ratio for hydroxychloroquine is at least equal to or better than that of chloroquine, and when the currently recommended dosages of 400 mg per day of hydroxychloroquine and 250 mg per day of chloroquine are not exceeded, this ratio is medically and ophthalmologically acceptable. The most useful tests to detect retinopathy are ophthalmoscopic and/or photographic observation of the macular area for changes in pigmentation, sensitive central visual field testing, and automated computerized perimeter. These tests can be conducted by the attending physician provided that (1) baseline ophthalmologic studies are done (to exclude pre-existing ocular abnormalities); (2) such studies are conducted every six months thereafter; and (3) the patient with ocular abnormalities is immediately referred to an ophthalmologist for further evaluation, even in the absence of symptoms.

Pharmacologic actions of 4-aminoquinoline compounds

The pharmacokinetics, physiologic effects, and the metabolization of chloroquine and hydroxychloroquine are all similar. Their concentrations in plasma and tissue are directly related to daily dosing. The highest concentrations are found in melanin-containing tissues, particularly the choroid and ciliary body of the eye. The pharmacologic effects of 4-aminoquinoline compounds are reviewed in detail. It is likely that the rheumatologic effectiveness of these agents is primarily related to lysosomal actions. The drug-induced lysosomal abnormalities include diminished vesicle fusion, diminished exocytosis, and reversible "lysosomal storage disease." It is likely that the retinal toxicity of these drugs is one manifestation of the altered lysosomal physiology involving the retinal pigmented epithelium. Tissue of retinal pigmented epithelium is similar to that of the bone-marrow-derived macrophage. Depression of extra-oculogram is an early sign of excessive dosage and can be used to measure potential toxicity during therapy with 4-aminoquinolines. Dosages ranging from 3.5 to 4.0 mg/kg per day for chloroquine and 6.0 to 6.5 mg/kg per day for hydroxychloroquine are clinically safe.

Dose refinements in long-term therapy of rheumatoid arthritis with antimalarials

No eye disease was detected in over 900 rheumatoid arthritis patients treated with less than 4.0 mg/kg per day of chloroquine or less than 6.5 mg/kg per day of hydroxychloroquine for a mean of about seven years. I therefore consider these dosage rates safe, since they are below the threshold of retinal toxicity. This is based on more than 6,000 patient-years of drug exposure. That dosage threshold for retinopathy appears to be 5.1 mg/kg per day for chloroquine and 7.8 mg/kg per day for hydroxychloroquine according to my studies with these compounds. The daily dosage rate, rather than total drug accumulation, seems to determine the development of eye disease. To prevent overdosage, dosing should be calculated not on the actual weight of the patient but on ideal (lean) body weight. Furthermore, the patient's renal and liver function should also be taken into account to avoid overdosage. Since exposure to light amplifies the risk of retinopathy in patients treated with antimalarials, dark sunglasses are recommended for patients spending much time in sunlight.

Adverse ocular reactions to drugs

Drugs acting on various parts of the body may also affect the eye insidiously. Increased awareness of such drug toxicity by the prescribing doctor should encourage him to consider effects on the cornea, lens, retina, optic nerve and elsewhere when checking the patient's progress. The following review concerns adverse ocular effects of systemic drug administration.

Antimalarials in rheumatic diseases

The use of antimalarials in rheumatoid arthritis (RA) and systemic lupus erythematosis (SLE) has declined over recent years due to concern over retinal toxicity and the impression that this class of drugs is relatively ineffective in rheumatic diseases. Recent reviews suggest that this position should be changed. Firstly, there is now good evidence for the efficacy of these drugs in RA and secondly strict control of the daily dosage and careful ophthalmological surveillance can almost eliminate the risk of serious retinal toxicity.

Therapy of cutaneous lupus erythematosus

Cutaneous lupus erythematosus occurs in a spectrum from limited cutaneous disease to severe systemic disease. Chronic DLE generally follows a benign course, but rare transformation to systemic disease may occur. Subacute cutaneous LE is associated with a specific cutaneous lesion and mild to moderate systemic symptoms. Cutaneous disease should be managed by an experienced physician and can lead to control of the process.

Systemic lupus erythematosus: important considerations in the adolescent

Systemic Lupus Erythematosus (SLE) may be particularly devastating to the adolescent female because of the marked changes in appearance which may result from the disease and by its treatment. Attention is drawn to the potential of the patient manipulating her medications in response to these changes. Other special considerations include the unique side-effects of corticosteroid and antimalarial drugs, the need to distinguish psychological reactions to SLE from true organic involvement and an added risk for a flare of disease activity in the sexually active patient. A case of a teenage female with SLE is used to illustrate some of the management problems which may be encountered.

Antimalarials and ophthalmologic safety

Antimalarial drugs were shown to be useful agents in the treatment of discoid and systemic lupus erythematosus in 1951. However, by 1966, fear of retinal toxicity and the availability of alternative therapies had led to limited use of antimalarials. Continued experience with these alternative therapies has made their intrinsic, sometimes devastating toxicities more evident and has contributed to the renewed interest in antimalarial agents evident in the number of comprehensive reviews appearing recently in the dermatology literature. Many of these reviews, while generally excellent, have propagated some apparent misconceptions by disregarding or de-emphasizing data suggesting that irreversible retinal toxicity due to antimalarials can be easily avoided by judicious daily dosage and regular ophthalmologic follow-up. This article will discuss the historical basis of these misconceptions and the subsequent studies which suggest that antimalarial retinal toxicity can be avoided without sacrificing the therapeutic efficacy of these agents.

Lupus erythematosus

Lupus erythematosus (LE) is a multisystem disease. Genetic predisposition, altered immunity, hormones, drugs, viruses, and ultraviolet light all may play a role in etiology. A wide range of cutaneous lesions occur, and variants such as subacute cutaneous LE, complement-deficient LE, and neonatal LE have recently been emphasized. Management of the LE patient, including appropriate diagnostic studies and therapy relevant to the dermatologist, is discussed in the review.

Pharmacotherapy of juvenile rheumatoid arthritis

Salicylate is the drug of first choice in the initial treatment of juvenile rheumatoid arthritis. In therapeutic dosage it will adequately control joint symptoms in the majority of patients. For children who do not respond to or are intolerant of salicylate, a change to one of the other nonsteroidal anti-inflammatory agents is appropriate. In progressive polyarthritis unresponsive to the above agents, the addition of gold, antimalarials, or penicillamine is indicated, preferably in that order. Corticosteroid therapy should be reserved for selected patients meeting specific criteria. Pharmacotherapy of juvenile rheumatoid arthritis should always be individualized. For optimal treatment of the whole child it must be combined with both physical and educational measures.

The effect of fasting on plasma cyclic adenosine-3', 5'-monophosphate in rheumatoid arthritis

Cyclic adenosine-3', 5'-monophosphate (cAMP) may influence important mechanisms in the inflammatory process, and fasting has been claimed to be clinically beneficial in rheumatoid arthritis (RA). A study was therefore designed to measure the concentrations of plasma cAMP in RA patients not undergoing drug treatment during a control and a fasting period. Twelve female RA patients were hospitalized for two 14-day periods and investigated in a crossover study. Clinical and laboratory variables of inflammatory activity were assessed during both periods. During the control period the concentrations of cAMP in plasma were slightly below the lower normal limit, with no significant change throughout the period. The clinical and laboratory variables of inflammatory activity were unchanged during the same period. In the fasting period, the prefasting level of plasma cAMP was significantly higher than on the corresponding day in the control period. During 7 days of total fasting the plasma cAMP concentrations decreased significantly. The clinical and laboratory variables of inflammatory activity decreased significantly from the start to the end of fasting. High prefasting plasma cAMP concentrations were associated with improvement in clinical inflammatory activity. A decrease in plasma cAMP concentrations during fasting in RA patients is in contrast to the findings in obese and healthy subjects previously reported.