Is inhibition of nitric oxide synthase a mechanism for SSRI-induced bleeding?

Bleeding induced by SSRIs

Selective Serotonin Reuptake Inhibitors (SSRIs) have been accused of causing bleeding problems as a side effect. Theories about the mechanism are still being discussed. We report a case, presenting bleeding problems, during sertraline treatment. The SSRIs are widely used to treat depression and many other psychiatric disorders. Their lower severity of side effects and being markedly safer in overdose are some of the reasons of their preference as primary choice in most of the cases. Besides their common side effects like, agitation, headache, insomnia, weight gain or loss, and sexual dysfunction, SSRIs also have been suspected of increasing the risk of bleeding. A population-based cohort study supported the hypothesis of an increased risk of upper gastrointestinal bleeding during the use of SSRIs, and they also indicated that this effect is potentiated with concurrent use of NSAIDs or low-dose aspirin. We would like to report our recent experience with one patient who was on sertraline, 50mg/day.

Selective Serotonin Reuptake Inhibitor Use and Risk of Gastrointestinal and Intracranial Bleeding

Selective serotonin reuptake inhibitors (SSRIs) are among the most commonly prescribed medications in the United States. Although SSRIs are highly tolerable relative to other antidepressants, they are associated with a number of adverse effects, including increased gastrointestinal tract bleeding and intracranial bleeding. Mechanisms include increased gastric acid secretion and inhibition of serotonin entrance into platelets. Patients with other bleeding risk factors, such as warfarin, clopidogrel, or aspirin use, may be at heightened risk of these adverse effects. The purpose of this article is to review the incidence of gastrointestinal tract bleeding or intracranial bleeding associated with concomitant SSRI use, the proposed mechanisms of, and the potential pharmacokinetic/pharmacodynamic interactions with anticoagulants and antiplatelets. Given the prevalence of SSRI use in the ambulatory setting, osteopathic physicians should be aware of potential drug-drug interactions and the clinical implications of SSRI-associated bleeding risk.

Serotonin Reuptake Inhibitors and Risk of Abnormal Bleeding

Serotonin reuptake inhibitors (SRIs) increase the risk of abnormal bleeding by lowering platelet serotonin and hence the efficiency of platelet-driven hemostasis; by increasing gastric acidity and possibly gastric ulceration; and by other mechanisms. The upper gastrointestinal tract is the commonest site of SRI-related abnormal bleeding; bleeding at this location may be increased by concurrent nonsteroidal anti-inflammatory drug therapy and by treatment with antiplatelet or anticoagulant drugs. Bleeding at this location may be reduced by concurrent administration of acid-suppressing drugs.

The platelet of the patients with ischemic cardiopathy and cardiac valve disease showed a reduction of 8OH-DPAT binding sites

Depression is prospectively associated with increased risk of coronary artery disease in individuals initially free of clinical cardiovascular disease probably by an increased platelet activity. The serotonergic receptors mainly implied in depression are 5-HT1A and 5-HT2 receptors. Activation of 5HT2 receptor induces platelet aggregation. Drugs with 5-HT1A receptor agonist and 5-HT2A receptor antagonist effects reduced the receptor-mediated platelet aggregation. There are only indirect data about 5-HT1A receptors presence in platelet membranes, thus our aims were to study the characteristics of the platelet membranes 5-HT1A binding sites of both healthy volunteers and patients with cardiac valve disease and ischemic cardiopathy. The bound of the 5-HT1A selective agonist 3H-8OH-DPAT to the platelet membranes 5-HT1A binding sites of patients with cardiac valve disease and ischemic cardiopathy were compared with a control group of healthy voluntaries using radioligand binding methods. The patients with cardiovascular disease showed a reduction (-50.40%) (p<0.01) of the 3H-8OH-DPAT bound to the platelet membranes 5-HT1A receptors (1.652+/-0.79 fmol/mg protein) with respect to the control group (3.331+/-0.16 fmol/mg protein). 3H-8OH-DPAT binding to human platelet membranes is saturable, of high affinity, and seems selective for 5-HT1A receptors, and similar to that described in animal brain and in other human cells. Patients with ischemic cardiopathy and cardiac valve disease showed a reduction of the 8OH-DPAT bound to the platelet membranes. Taken together, these findings suggest that the 8OH-DPAT bound to the human platelet membranes is modulated by modifications produced by cardiovascular disease conditions.

Ecchymoses as an adverse effect of fluoxetine treatment

We report a case of a 28-year-old major depressive female patient who manifested ecchymoses following fluoxetine use. After substitution of sertraline, her depression resolved after 4 weeks and ecchymoses 1.5 months latter. This is an unexplored side-effect with unknown long-term consequences that warrants further study.

Influence of antidepressants on hemostasis

Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), are widely used for the treatment of depression and anxious disorders. The observation that depression is an independent risk factor for cardiovascular mortality and morbidity in patients with ischemic heart disease, the assessment of the central role of serotonin in pathophysiological mechanisms of depression, and reports of cases of abnormal bleeding associated with antidepressant therapy have led to investigations of the influence of antidepressants on hemostasis markers. In this review, we summarize data regarding modifications of these markers, drawn from clinical studies and case reports. We observed an association between the type of antidepressant drug and the number of abnormal bleeding case reports, with or without modifications of hemostasis markers. Drugs with the highest degree of serotonin reuptake inhibition - fluoxetine, paroxetine, and sertraline - are more frequently associated with abnormal bleeding and modifications of hemostasis markers. The most frequent hemostatic abnormalities are decreased platelet aggregability and activity, and prolongation of bleeding time. Patients with a history of coagulation disorders, especially suspected or documented thrombocytopenia or platelet disorder, should be monitored in case of prescription of any serotonin reuptake inhibitor (SRI). Platelet dysfunction, coagulation disorder, and von Willebrand disease should be sought in any case of abnormal bleeding occurring during treatment with an SRI. Also, a non-SSRI antidepressant should be favored over an SSRI or an SRI in such a context. Considering the difficulty in performing platelet aggregation tests, which are the most sensitive in SRI-associated bleeding, and the low sensitivity of hemostasis tests when performed in case of uncomplicated bleeding in the general population, establishing guidelines for the assessment of SRI-associated bleeding complications remains a challenge.

Clinical impact of selective serotonin reuptake inhibitors therapy with bleeding risks

The selective serotonin reuptake inhibitors (SSRIs) are extensively used for the treatment of multiple psychiatric conditions. In vitro and ex vivo data with these agents indicate they may have varying degrees of antiplatelet activity via multiple receptors. Reports of bleeding in patients receiving SSRIs appeared soon after their introduction. A review of the literature suggests SSRI therapy may increase the risk of bleeding especially with concomitant aspirin or nonsteroidal anti-inflammatory agents. Clinicians should exercise caution when prescribing these agents in high risk patients and maintain awareness of the potential contribution of SSRIs to unexplained bleeding episodes.

SSRIs and upper gastrointestinal bleeding: what is known and how should it influence prescribing?

SSRIs have achieved a high usage rate in the treatment of depression because of a similar efficacy to TCAs and a favourable safety and tolerability profile. However, SSRI use has been associated with bleeding. We reviewed the epidemiological evidence on the association between SSRI use alone and the risk of upper gastrointestinal bleeding, and on synergistic effects reported with other commonly used drugs that can also cause bleeding.A literature search identified four studies of SSRI use and risk for upper gastrointestinal bleeding and a further two studies of SSRI use and bleeding in general, including upper gastrointestinal bleeding. The available evidence indicates quite convincingly that SSRI use may play a causal role in upper gastrointestinal bleeding and that these drugs may act synergistically with other bleeding risk-increasing medications such as NSAIDs or low-dose aspirin. Assuming a causal role of SSRIs, reported excess gastrointestinal bleedings attributable to SSRI use was reported to be 3.1 per 1000 treatment years, 4.1 per 1000 treatment years among octogenarians and 11.7 per 1000 treatment years among persons with prior upper gastrointestinal bleeding. These non-negligible risks warrant that prescribing doctors consider strategies on the individual level to reduce the likelihood of an upper gastrointestinal adverse event. Patients at particular risk include those with previous ulcers or gastrointestinal bleeding, the elderly and those with certain concurrent illnesses and/or high-risk comedications. Suggested strategies include alternatives to SSRI use, prescribing of less gastrotoxic NSAIDs or co-prescribing of gastroprotective drugs. Patients should be informed about the likelihood of possible upper gastrointestinal bleeding and high-risk patients should be followed closely.

Selective serotonin reuptake inhibitors and increased bleeding risk: are we missing something?

PURPOSE

Selective serotonin reuptake inhibitors (SSRIs) are first line agents to treat clinical depression. Although these medications exhibit a favorable safety profile, there are multiple case reports, registries, and uncontrolled studies suggesting that use of SSRIs might be associated in the increased risk of bleeding events. There is also emerging evidence that these side effects of SSRIs are due to blockade of serotonin reuptake in platelets and subsequent platelet dysfunction.

METHODS

The analysis of evidence linking SSRIs with bleeding episodes to define the prevalence, specific clinical characteristics, and estimated risk when SSRIs are used in combination with antiplatelet agents or/and anticoagulants.

RESULTS

There are over 120 MEDLINE-cited peer-reviewed research papers and more than 50000 Web pages devoted to SSRI-related bleeding events.

CONCLUSION

Independently of the brand, use of SSRIs is indeed associated with increased bleeding risk. Although such complications are rare, their frequency is growing, and physicians should be aware of SSRI-induced hemorrhages, especially in patients with hereditary platelet defects, and those treated with antiplatelet agents. Prospective studies are urgently needed to determine whether SSRIs will yield additional bleeding risks when used long term concomitantly with aspirin or clopidogrel.

Selective serotonin re-uptake inhibitors and the risk of bleeding

Despite their safety, selective serotonin re-uptake inhibitors (SSRIs) are associated with bleeding. The authors critically reviewed the medical literature on SSRIs to identify subgroups of patients at risk of bleeding complications. The authors performed a literature search using MEDLINE from 1966 to 1st September 2004 using; 'haemorrhage, serotonin uptake inhibitors and antidepressive agents' as search terms and followed up on citations in each paper that was relevant to SSRI associated bleeding. The authors reviewed 7 retrospective analytical studies and 24 case reports of bleeding in 43 different people. Analytical studies support an association between SSRI consumption and upper gastrointestinal (GI) bleeding and perioperative bleeding. Little evidence links SSRI use with intracerebral haemorrhage. The risk of GI bleeding appeared to be highest among patients consuming SSRIs with NSAIDs. Combining aspirin or NSAIDs with SSRIs may further increase the risk of bleeding. Clinicians should caution patients about combining SSRIs with aspirin or NSAIDs. Pharmacotherapy to reduce the risk of GI bleeding should be considered in high risk patients.