Clinical Briefs

By Louis Kuritzky, MD, Clinical Assistant Professor, University of Florida, Gainesville. Dr. Kuritzky is an advisor for Endo, Kowa, Pricara, and Takeda.

Long-term Prevention of Recurrent DVT

Source: Brighton TA, et al. Low-dose aspirin for preventing recurrent venous thromboembolism. N Engl J Med 2012; 367:1979-1987.

Current guidelines for management of venous thrombosis (e.g., the Antithrombotic 9 guideline published by the American College of Chest Physicians in 2012) suggest that after an initial episode of unprovoked deep venous thrombosis (DVT), it is reasonable to provide at least a 3-month course of anticoagulation, with consideration of a longer interval on a case-by-case basis. Usually, anticoagulation is not continued long-term. But the risk of DVT recurrence after cessation of coumadin is not insignificant.

Aspirin (ASA) is easy to administer and has a generally favorable risk profile. After cessation of coumadin, Brighton et al compared DVT patients treated with aspirin vs placebo for approximately 3 years. Although numerically fewer recurrent DVT episodes occurred in the ASA group, the numbers did not achieve statistical significance (4.8%/yr vs 6.5%/yr; P = 0.09). On the other hand, ASA produced a reduction in secondary composite outcomes, which included myocardial infarction, stroke, and cardiovascular death. Hence, even though ASA did not produce a statistically significant reduction in DVT, the potential reduction in other cardiovascular adversities might tip the balance toward benefit. Because the primary endpoint of the trial was not met, secondary endpoints, however, must be considered hypothesis generating rather than conclusive.


Marijuana and the Risk of Schizophrenia

Source: Evins AE. The effect of marijuana use on the risk for schizophrenia. J Clin Psychiatry 2012;73:1463-1468.

The recent legalization of marijuana in two states has brought the discussion of potential toxicity to the fore. Although it is unclear what impact legalization will have on epidemiology of marijuana use, most experts agree that more widespread and heavier marijuana use would not be at all surprising. The psychiatry community has particular concern about marijuana use because observational data suggest that early (during adolescence) marijuana use is associated with an increased risk for an earlier onset of schizophrenia.

Most schizophrenia is genetic in origin (80%). Hence, if marijuana is a contributor to schizophrenia, it occurs in a minority of cases. On the other hand, some genetic predilection for development of schizophrenia can be seen in carriers of the Met allele of the COMT gene, who appear especially likely to develop psychosis subsequent to cannabis use in adolescence.

At the current time, experts suggest advising parents that marijuana use in adolescence, especially heavy use, may increase the risk of future schizophrenia, and for persons with existing psychosis, may make symptoms worse.


Losartan Improves Erectile Function in Diabetics

Source: Chen Y, et al. Losartan improves erectile dysfunction in diabetic patients: A clinical trial. Internat J Impot Res 2012;24:217-220.

Animal studies have shown that high levels of angiotensin II (ANG2) in the corpora cavernosa of the penis extinguish erections, the effect of which can be blocked by losartan, an ANG2 receptor blocker. Whether losartan might have a favorable effect on erectile dysfunction (ED) in diabetic humans has not been definitively confirmed.

Chen et al studied diabetic adults with ED (n = 124) who were randomized to receive either LOS 50 mg/d alone, tadalafil 5 mg/d (TAD) alone, the combination of LOS + TAD, or no treatment for 12 weeks. Persons with poorly controlled hypertension were excluded from the trial.

At the conclusion of the trial, TAD and LOS provided comparable significant improvements in erectile function scores, but the LOS + TAD combination was significantly better than either monotherapy. The control group experienced no significant improvement in erectile function. LOS was very well tolerated, and tolerability was not compromised by combining LOS + TAD. Clinicians might consider the addition of LOS to patients with insufficient ED response to TAD alone.