Chloroquine influences renal function in rural Zimbabweans with acute transient fever

Drugs Used in the Treatment of Rheumatoid Arthritis: Relationship between Current Use and Cardiovascular Risk Factors

Objectives

Drugs used for the treatment of rheumatoid arthritis (RA) have the potential to affect cardiovascular risk factors. There is concern that corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors could affect cardiovascular risk adversely, while drugs such as the antimalarial, hydroxychloroquine, may have beneficial effects. However, there is limited information about cardiovascular risk factors in patients with RA receiving different drugs.

Methods

We measured cardiovascular risk factors including systolic and diastolic blood pressure, serum HDL and LDL cholesterol, glucose and homocysteine concentrations and urinary F₂-isoprostane excretion in 169 patients with RA. Risk factors were compared according to current use of corticosteroids, methotrexate, antimalarials, NSAIDs, COX-2 inhibitors, leflunomide and TNF-α blockers. Comparisons were adjusted for age, sex, race, disease activity (DAS28 score), current hypertension, diabetes, smoking status and statin use.

Results

No cardiovascular risk factor differed significantly among current users and non-users of NSAIDs, COX-2 inhibitors, methotrexate and TNF-α blockers. Serum HDL cholesterol concentrations were significantly higher in patients currently receiving corticosteroids (42.2 ± 10.5 vs. 50.2 ± 15.3 mg/dL, adjusted P < 0.001). Diastolic blood pressure (75.9 ± 11.2 vs. 72.0 ± 9.1 mm Hg, adjusted P = 0.02), serum LDL cholesterol (115.6 ± 34.7 vs. 103.7 ± 27.8 mg/dL, adjusted P = 0.03) and triglyceride concentrations (157.7 ± 202.6 vs. 105.5 ± 50.5 mg/dL, adjusted P = 0.03) were significantly lower in patients taking antimalarial drugs. Plasma glucose was significantly lower in current lefunomide users (93.0 ± 19.2 vs. 83.6 ± 13.4 mg/dL, adjusted P = 0.006).

Conclusions

In a cross-sectional setting drugs used to treat RA did not have major adverse effects on cardiovascular risk factors and use of antimalarials was associated with beneficial lipid profiles.

Renal electrolyte and fluid handling in the rat following chloroquine and/or ethanol administration

We postulated that chloroquine and/or ethanol affect plasma arginine vasopressin (AVP) concentrations to alter renal function. Therefore, we studied the effects of chloroquine and/or ethanol on plasma AVP concentrations and fluid, urinary Na(+) and K(+) outputs in separate groups of anaesthetized Sprague-Dawley (SD) rats challenged with a continuous jugular infusion of 0.077 M NaCl at 150 microl.min(-1). After a 3-h equilibration period, vehicle, chloroquine (0.06 microg. min(-1)), ethanol (2.4 or 24 microg.min(-1)) or both chloroquine and ethanol were added to the infusate after 1 h (control) for 1 h 20 min (treatment). The animals were switched back to the infusate alone for the final 1 h 40 min recovery periods. Urine flow Na(+) and K(+) excretion rates were determined at 20-min intervals over the subsequent 4-h postequilibration period. Blood was collected from separate groups of animals at the end of treatment period or equivalent time for control animals for measurement of plasma aldosterone and AVP concentrations by radioimmunoassay. Simultaneous chloroquine and ethanol infusion significantly (p < 0.01) increased plasma chloroquine concentrations in an ethanol dose-dependent manner by comparison with animals administered chloroquine alone. Chloroquine infusion alone (0.06 microg.min(-1)) and/or ethanol (2.4 or 24 microg.min(-1)) elevated plasma AVP concentrations from 9.73 +/- 1.64 fmol.l(-1) in control rats to 15.65 +/- 2.49 fmol.l(-1), 17. 39 +/- 4.21 fmol.l(-1), and 33.87 +/- 6.18 fmol.l(-1), respectively. Separate administration of chloroquine or ethanol at low dose rates increased urinary Na(+) excretion rates. We conclude that the impairment of renal electrolyte handling associated with chloroquine administration may be exacerbated by ethanol.