Andrew Carr

Posterior reversible encephalopathy syndrome (PRES) is an uncommon pathology characterized by the acute onset of headache, vomiting, altered consciousness, seizures and focal neurological deficits. It was initially described in the setting of hypertension, uremia and immunosuppression. In the last decade there have been emerging reports of PRES in patients with advanced human immunodeficiency virus (HIV)-infection in the presence of hypertension, dialysis, hypercalcaemia and two opportunistic infections: blastomycosis and tuberculosis (TB).

Using the SWITCHMRK and MONET trials as examples, Andrew Carr and colleagues question the ethics and motives of switch or simplification trials of anti-retroviral therapy.

Objectives: Financial stress has been identified as a barrier to antiretroviral adherence, but only in resource‐ limited settings. Almost half of HIV‐infected Australian adults earn no regular income and, despite highly subsidised antiretroviral therapy and universal health care, 3% of HIV‐infected Australians cease antiretroviral therapy each year. We studied the relationship between financial stress and treatment adherence in a resource‐rich setting.Methods: Out‐patients attending the HIV clinic at St Vincent's Hospital between November 2010 and May 2011 were invited to complete an anonymous survey including questions relating to costs and adherence.Results: Of 335 HIV‐infected patients (95.8% male; mean age 52 years; hepatitis coinfection 9.2%), 65 patients (19.6%) stated that it was difficult or very difficult to meet pharmacy dispensing costs, 49 (14.6%) reported that they had delayed purchasing medication because of pharmacy costs, and 30 (9.0%) reported that they had ceased medication because of pharmacy costs. Of the 65 patients with difficulties meeting pharmacy costs, 19 (29.2%) had ceased medication vs. 11 (4.1%) of the remaining 270 patients (P < 0.0001). In addition, 19 patients (5.7%) also stated that it was difficult or very difficult to meet travel costs to the clinic. Treatment cessation and interruption were both independently associated with difficulty meeting both pharmacy and clinic travel costs. Only 4.9% had been asked if they were having difficulty paying for medication.Conclusions: These are the first data to show that pharmacy dispensing and clinic travel costs may affect treatment adherence in a resource‐rich setting. Patients should be asked if financial stress is limiting their treatment adherence.

(See the article by Ganesan et al., on pages 756–764 )

Potential conflicts of interest. A.C. has received research funding from Abbott, Bristol-Myers Squibb, GlaxoSmithKline, and Merck; consultancy fees from Bristol

Abacavir's effect on cardiovascular function has not been studied prospectively. We measured augmentation index (a measure of arterial stiffness) in 20 men who switched from abacavir to tenofovir. After 4 weeks, mean augmentation index reduced from 22% by 4% (P = 0.03) and Framingham risk score by 2% (P = 0.01), which was driven by lower total cholesterol (0.8 mmol/l; P = 0.002). Consistent trends were observed through week 24. Changes in C-reactive protein, interleukin-6 and D-dimer were inconsistent and only occurred from week 12. Abacavir may impair cardiovascular function by increasing total cholesterol levels.

Background: Significant nephrotoxicity develops in 1%-2% of HIV-infected adults receiving tenofovir (TDF). This nephrotoxicity is said to resolve rapidly, but this assessment is based on short follow-up, very few patients and use of serum creatinine, an insensitive measure of renal function. Methods: We determined the reversibility of TDF-related nephrotoxicity in 24 HIV-infected male outpatients who ceased TDF for renal impairment by retrospective assessment of estimated glomerular filtration rate (eGFR) using the Modified Diet in Renal Disease equation. Results: Median (interquartile range) eGFR pre-TDF was 74 (61-88) mL·min⁻¹·1.73 m⁻², fell to 51 (39-61) mL·min⁻¹·1.73 m⁻² at TDF cessation and increased to 58 (48-70) mL·min⁻¹·1.73 m⁻² a median 13 months after TDF cessation (most recent vs pre-TDF eGFR; P = 0.0008). Results were similar with the Cockcroft-Gault equation and after exclusion of patients who had shorter follow-up after TDF cessation. Only 10 (42%) patients reached their pre-TDF eGFR. Greater eGFR improvement was significantly associated with more rapid decline in eGFR on TDF therapy and in those who received TDF with a protease inhibitor, with a trend for shorter duration of TDF therapy. Discussion: In this population, TDF-related renal toxicity was not always fully reversible.

To the Editor—Landman and Soonawala [1] rightly state that the rates of virologic failure in the per protocol population (1.1% in each arm) were far less than t

Background. There are 2 once-daily, fixed-dose-combination, dual-nucleoside analogue tablets: tenofovir 300 mg-emtricitabine 200 mg (TDF-FTC) and abacavir 600 mg-lamivudine 300 mg (ABC-3TC). Which fixed-dose-combination tablet is more effective and safe is uncertain.