Favorable Antiviral Effect of Metformin on Severe Acute Respiratory Syndrome Coronavirus 2 Viral Load in a Randomized, Placebo-Controlled Clinical Trial of Coronavirus Disease 2019

BACKGROUND

Metformin has antiviral activity against RNA viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The mechanism appears to be suppression of protein translation via targeting the host mechanistic target of rapamycin pathway. In the COVID-OUT randomized trial for outpatient coronavirus disease 2019 (COVID-19), metformin reduced the odds of hospitalizations/death through 28 days by 58%, of emergency department visits/hospitalizations/death through 14 days by 42%, and of long COVID through 10 months by 42%.

METHODS

COVID-OUT was a 2 × 3 randomized, placebo-controlled, double-blind trial that assessed metformin, fluvoxamine, and ivermectin; 999 participants self-collected anterior nasal swabs on day 1 (n = 945), day 5 (n = 871), and day 10 (n = 775). Viral load was quantified using reverse-transcription quantitative polymerase chain reaction.

RESULTS

The mean SARS-CoV-2 viral load was reduced 3.6-fold with metformin relative to placebo (-0.56 log10 copies/mL; 95% confidence interval [CI], -1.05 to -.06; P = .027). Those who received metformin were less likely to have a detectable viral load than placebo at day 5 or day 10 (odds ratio [OR], 0.72; 95% CI, .55 to .94). Viral rebound, defined as a higher viral load at day 10 than day 5, was less frequent with metformin (3.28%) than placebo (5.95%; OR, 0.68; 95% CI, .36 to 1.29). The metformin effect was consistent across subgroups and increased over time. Neither ivermectin nor fluvoxamine showed effect over placebo.

CONCLUSIONS

In this randomized, placebo-controlled trial of outpatient treatment of SARS-CoV-2, metformin significantly reduced SARS-CoV-2 viral load, which may explain the clinical benefits in this trial. Metformin is pleiotropic with other actions that are relevant to COVID-19 pathophysiology.

CLINICAL TRIALS REGISTRATION

NCT04510194.

Metformin reduces SARS-CoV-2 in a Phase 3 Randomized Placebo Controlled Clinical Trial

Current antiviral treatment options for SARS-CoV-2 infections are not available globally, cannot be used with many medications, and are limited to virus-specific targets.1-3 Biophysical modeling of SARS-CoV-2 replication predicted that protein translation is an especially attractive target for antiviral therapy.4 Literature review identified metformin, widely known as a treatment for diabetes, as a potential suppressor of protein translation via targeting of the host mTor pathway.5 In vitro, metformin has antiviral activity against RNA viruses including SARS-CoV-2.6,7 In the COVID-OUT phase 3, randomized, placebo-controlled trial of outpatient treatment of COVID-19, metformin had a 42% reduction in ER visits/hospitalizations/death through 14 days; a 58% reduction in hospitalizations/death through 28 days, and a 42% reduction in Long COVID through 10 months.8,9 Here we show viral load analysis of specimens collected in the COVID-OUT trial that the mean SARS-CoV-2 viral load was reduced 3.6-fold with metformin relative to placebo (-0.56 log10 copies/mL; 95%CI, -1.05 to -0.06, p=0.027) while there was no virologic effect for ivermectin or fluvoxamine vs placebo. The metformin effect was consistent across subgroups and with emerging data.10,11 Our results demonstrate, consistent with model predictions, that a safe, widely available,12 well-tolerated, and inexpensive oral medication, metformin, can be repurposed to significantly reduce SARS-CoV-2 viral load.

Impact of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccination and Booster on Coronavirus Disease 2019 (COVID-19) Symptom Severity Over Time in the COVID-OUT Trial

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination has decreasing protection from acquiring any infection with emergence of new variants; however, vaccination continues to protect against progression to severe coronavirus disease 2019 (COVID-19). The impact of vaccination status on symptoms over time is less clear.

METHODS

Within a randomized trial on early outpatient COVID-19 therapy testing metformin, ivermectin, and/or fluvoxamine, participants recorded symptoms daily for 14 days. Participants were given a paper symptom diary allowing them to circle the severity of 14 symptoms as none (0), mild (1), moderate (2), or severe (3). This is a secondary analysis of clinical trial data on symptom severity over time using generalized estimating equations comparing those unvaccinated, SARS-CoV-2 vaccinated with primary vaccine series only, or vaccine-boosted.

RESULTS

The parent clinical trial prospectively enrolled 1323 participants, of whom 1062 (80%) prospectively recorded some daily symptom data. Of these, 480 (45%) were unvaccinated, 530 (50%) were vaccinated with primary series only, and 52 (5%) vaccine-boosted. Overall symptom severity was least for the vaccine-boosted group and most severe for unvaccinated at baseline and over the 14 days (P < .001). Individual symptoms were least severe in the vaccine-boosted group including cough, chills, fever, nausea, fatigue, myalgia, headache, and diarrhea, as well as smell and taste abnormalities. Results were consistent over Delta and Omicron variant time periods.

CONCLUSIONS

SARS-CoV-2 vaccine-boosted participants had the least severe symptoms during COVID-19, which abated the quickest over time. Clinical Trial Registration. NCT04510194.

Randomized Trial of Metformin, Ivermectin, and Fluvoxamine for Covid-19

BACKGROUND

Early treatment to prevent severe coronavirus disease 2019 (Covid-19) is an important component of the comprehensive response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.

METHODS

In this phase 3, double-blind, randomized, placebo-controlled trial, we used a 2-by-3 factorial design to test the effectiveness of three repurposed drugs - metformin, ivermectin, and fluvoxamine - in preventing serious SARS-CoV-2 infection in nonhospitalized adults who had been enrolled within 3 days after a confirmed diagnosis of infection and less than 7 days after the onset of symptoms. The patients were between the ages of 30 and 85 years, and all had either overweight or obesity. The primary composite end point was hypoxemia (≤93% oxygen saturation on home oximetry), emergency department visit, hospitalization, or death. All analyses used controls who had undergone concurrent randomization and were adjusted for SARS-CoV-2 vaccination and receipt of other trial medications.

RESULTS

A total of 1431 patients underwent randomization; of these patients, 1323 were included in the primary analysis. The median age of the patients was 46 years; 56% were female (6% of whom were pregnant), and 52% had been vaccinated. The adjusted odds ratio for a primary event was 0.84 (95% confidence interval [CI], 0.66 to 1.09; P = 0.19) with metformin, 1.05 (95% CI, 0.76 to 1.45; P = 0.78) with ivermectin, and 0.94 (95% CI, 0.66 to 1.36; P = 0.75) with fluvoxamine. In prespecified secondary analyses, the adjusted odds ratio for emergency department visit, hospitalization, or death was 0.58 (95% CI, 0.35 to 0.94) with metformin, 1.39 (95% CI, 0.72 to 2.69) with ivermectin, and 1.17 (95% CI, 0.57 to 2.40) with fluvoxamine. The adjusted odds ratio for hospitalization or death was 0.47 (95% CI, 0.20 to 1.11) with metformin, 0.73 (95% CI, 0.19 to 2.77) with ivermectin, and 1.11 (95% CI, 0.33 to 3.76) with fluvoxamine.

CONCLUSIONS

None of the three medications that were evaluated prevented the occurrence of hypoxemia, an emergency department visit, hospitalization, or death associated with Covid-19. (Funded by the Parsemus Foundation and others; COVID-OUT ClinicalTrials.gov number, NCT04510194.).

Menstrual timing of breast cancer surgery

PURPOSE AND DESIGN

This is a critical review of the growing body of data, 32 retrospective studies of the outcomes of 9,665 women published since 1989, relevant to the possibility that the timing of primary breast cancer resection within the menstrual cycle impacts breast cancer recurrence and/or spread and patient survival. This article evaluates and contrasts the adequacy of information and data analysis presented in each publication. The overall purpose of this exercise is to rigorously determine the relative strength of the hypothesis that the menstrual cycle timing of operation impacts outcome and, thereby, to determine whether or not a specific change in the practice of breast surgical oncology can be recommended.

RESULTS

The single most completely reported and thoroughly analyzed series, involving 1,175 young women, indicates that surgical resection timing is likely to be relevant to outcome. Seven additional high-quality studies involving 2,864 women have been most completely reported. While two of these eight find no impact, six (75%) of these studies find that breast cancer outcome is affected by operative timing. Nine of the remaining 24 less-complete studies report a statistically significant effect of operative timing. Among these 15 studies of the fates of more than 5,000 women, the opportune menstrual cycle phase almost invariably includes the putative luteal phase. A large number of retrospective studies of widely varying quality find no outcome difference as a function of resection timing. The adequacy of design of each of four ongoing prospective studies is found lacking.

CONCLUSIONS

Although it is likely that the menstrual cycle phase of operation is relevant to outcome, the nature of the available data cannot allow a clear recommendation of precisely when to operate. It is, therefore, concluded that current retrospective data are inadequate to recommend an immediate change in practice. Prospective studies of this potentially important question are essential. The prospective trials initiated to date will not be able to definitively answer this question because of inadequate chronobiological design. The minimal requirements for adequate prospective study are delineated.

Experimental diabetes: reduction of serotonin-induced vasoconstriction by meclofenamic acid in vitro

In diabetes the sensitivity of isolated rat aortae to serotonin is greatly diminished and the dose-response curve is shifted to the right. The maximal response is reduced to 37% of control, the threshold dose is approximately tenfold greater, and the ED50 is about fourfold greater than control. This decrease in sensitivity may be due, in part, to a reduction in the synthesis of prostaglandins because serotonin-induced responses in normal and diabetic arteries treated with meclofenamate are also significantly diminished. In addition, there is evidence that both receptor-operated Ca2+ and potential-operated Ca2+ channels may be impaired because the responses to norepinephrine and KCl are both dampened in diabetic aortae. The greatly diminished effect of serotonin may be a sensitive tool to study the nature of diabetes better and to monitor its development.

Effect of nonsteroid anti-inflammatory drugs on subarachnoid hemorrhage in dogs

The effects of two long-acting anti-inflammatory agents on behavioral changes and cerebral vasospasm were evaluated in a canine model of chronic subarachnoid hemorrhage (SAH). The agent with the longest half-life, sudoxicam, clearly reduced both the incidence and the magnitude of the vasopasm, and prevented the usual behavior changes caused by the stimulated SAH. The results obtained with the other agent, naproxen, suggested that it was better than the administration of saline. These agents were studied because of reports indicating that prostaglandins and thromboxane may play a role in the pathogenesis of the effects of SAH and because of nonsteroid anti-inflammatory agents exert pharmacological effects by reducing an excessive synthesis of these lipids. The findings suggest that some of these agents may afford an alternative treatment for the deterious consequences of SAH.

Experimental assessment of phenoxybenzamine in cerebral vasospasm

✓ The effect of phenoxybenzamine (PBZ) on cerebral vasospasm of the basilar artery induced by the injection of 2 ml of blood into the cisterna magna of dogs was assessed in chronic experiments. The presence of vasospasm was documented arteriographically. In one group of animals, 12 mg/kg of PBZ was given intravenously 2 hours before the intracisternal injection of blood to ascertain whether this drug would prevent the development of vasospasm for 24 hours. In another group of animals a 10−2M solution of PBZ was given intracisternally 15 minutes after vasospasm was produced, and again 24 hours afterward, to determine if the drug would reverse an existing spasm. These drug-treated animals were compared with controls which were treated with saline alone. The results indicate that the drug treatment was not statistically superior to saline in any of the groups studied. The finding that saline injected into the cisterna magna reversed the cerebral vasospasm illustrates the importance of this procedure in evaluating effectiveness of drugs and confirms the original observation that washing the cerebrospinal fluid with saline can terminate an experimentally induced vasospasm. Moreover, the fact that intracisternal injections of saline were more effective when given soon after the establishment of vasospasm than when injected 24 hours afterward supports the conclusion of others that the pathogenesis of cerebral vasospasm changes with time. The results also indicate that the presence of cerebral vasospasm in some animals did not prevent the return of normal behavior.

Levels and disappearance of prostaglandin F2alpha in cerebral spinal fluid: a clinical and experimental study

The concentration of prostaglandin F2alpha (PGF2alpha) was measured in cerebrospinal fluid (CSF) obtained by lumbar puncture in patients with subarachnoid hemorrhage and compared to control values. The level of this prostaglandin was elevated at some time in most patients during the course of their illness. However, this could not be correlated with the severity of neurological deficits observed. The possibility that the concentration of PGF2alpha in lumbar fluid may not reflect that present intracranially was tested experimentally in anesthetized dogs. In these experiments only a small fraction of the radioactive PGF2alpha injected into the cisterna magna appeared in lumbar CSF. Prostaglandin F2alpha rapidly disappeared from the cisterna magna, half time 8 minutes, and radioactivity was present in blood from the jugular vein indicating that normally this prostaglandin rapidly egresses from the CSF into blood. These findings suggest that PGF2alpha can be rapidly transported away from the brain. This could explain the low concentrations of PGF2alpha in CSF of normal individuals and in some patients who have severe cerebral vasospasm. Conversely, the elevation of PGF2alpha in lumbar CSF noted in some patients might be due, in part, to an impairment of transport caused by the size and location of the hemorrhage.

Pleocytosis and elevation of prostaglandins F2a and E2 in cerebrospinal fluid following intracisternal injection of thrombin

A marked pleocytosis and increase in the levels of prostaglandin F2a (PGF2a) and prostaglandin E2 (PGE2) were noted in cerebrospinal fluid of dogs within two hours following the intracisternal injection of thrombin. Quantitation of the prostaglandins (PG's) was done by gas chromatography-mass spectroscopy using deuterated PGF2a and PGE2 as internal standards. Whereas the levels of these prostaglandins were below the sensitivity of the method in control animals, a marked increase was noted following thrombin. PGF2a levels were 15-21 ng/ml and the PGE2 levels were 55-72 ng/ml. This concentration of the PG's is adequate to cause spasm of the cerebral vessels and could explain the spasm which occurs following the intracisternal injection of thrombin. These two effects, a pleocytosis and elevation of PG levels, may be specific to thrombin.

Experimental study on the genesis of cerebral vasospasm

The cerebral vasospasm produced by blood, fractions of blood, and blood-borne agents administered intracisternally was studied arteriographically to attain a better understanding of the genesis of vasospasm. The results indicate this phenomenon is multifarious in origin, involving a number of spasmogens. Whole blood, platelets, platelet extracts, some isolated components of platelets, plasma, thrombin, histamine, serotonin and prostaglandins F 1α , E 2 and F 2α produced a significant incidence and duration of spasm. Norepinephrine and prostaglandin E 1 were inactive. Spasm produced by arachidonic acid and red blood cells was of questionable significance.

Compared to whole blood, thrombin usually produced spasm which was more delayed in onset while most other active substances produced a shorter-lived spasm. However, among the pure substances tested, serotonin, prostaglandin E 2 and prostaglandin F 2α induced spasm in small doses which most nearly resembled that observed with whole blood.

The hypothesis that the course of spasm depends upon synthesis of spasmogens by brain and blood is advanced. Prostaglandin synthesis plays a major role in this concept.

Isolation of 15-alpha-hydroxy-oestriol from pregnancy urine and from the urine of newborn infants

From the extracts of enzyme- or acid hydrolysed pregnancy urine and urine of newborn infants a new oestrogen metabolite has been isolated. On the basis of the physical and chemical characteristics of this compound it is concluded that it is identical with 15α-hydroxy-oestriol (oestra-1,3,5(10)-triene-3,15α,16α,17β-tetrol).