Clinical pharmacokinetics of sertraline

Sertraline is a naphthalenamine derivative with the predominant pharmacological action of inhibiting presynaptic reuptake of serotonin from the synaptic cleft. It was initially marketed for the treatment of major depressive disorder and is now approved for the management of panic disorder, obsessive-compulsive disorder and post-traumatic stress disorder. Sertraline is slowly absorbed following oral administration and undergoes extensive first-pass oxidation to form N-desmethyl-sertraline, a weakly active metabolite that accumulates to a greater concentration in plasma than the parent drug at steady state. Sertraline is eliminated from the body by other metabolic pathways to form a ketone and an alcohol, which are largely excreted renally as conjugates. The elimination half-life of sertraline ranges from 22-36 hours, and once-daily administration is therapeutically effective. Steady-state plasma concentrations vary widely, up to 15-fold, in patients receiving usual antidepressant dosages between 50 and 150 mg/day. However, only sparse data have been published that support useful correlations between sertraline plasma concentrations and therapeutic or adverse effects to justify therapeutic drug monitoring. Sertraline has minimal inhibitory effects on the major cytochrome P450 enzymes, and few drug-drug interactions of clinical significance have been documented. Like other selective serotonin reuptake inhibitors, sertraline is well tolerated in therapeutic dosages and relatively safe in overdosage.

An unusual presentation of sertraline and trazodone overdose

OBJECTIVE

To report an unusual and life-threatening presentation of an overdose of sertraline and trazodone.

CASE SUMMARY

A patient with a history of depression ingested sertraline 6,000 mg and trazodone 1,300 mg in a suicide attempt. Twenty-four hours after antidepressant administration, the patient presented with symptoms of selective serotonin-reuptake inhibitor (SSRI) overdose and serotonin syndrome, and later developed an enlarged tongue consistent with angioedema. A compromised airway resulted and endotracheal intubation was necessary. After intubation, the symptoms subsided and the patient recovered.

DISCUSSION

Although SSRIs and trazodone are generally considered to be relatively safe in single-agent overdose, serious delayed reactions can occur, especially if several agents are involved. In this case the patient initially presented with symptoms typical of an SSRI overdose that did not appear to be exceptionally dangerous. Over time, symptoms consistent with angioedema appeared that necessitated intubation. Although previous reports of angioedema have been reported with SSRIs, this is the first report, to our knowledge, of a presentation this severe.

CONCLUSIONS

This case demonstrates that overdose with the newer antidepressants can result in unusual and delayed presentations and must be treated with caution.

Fatal multiple drug intoxication following acute sertraline use

A 53-year-old Caucasian male victim of suicide was suspected of overdose with sertraline and alprazolam after death-scene investigation. The concentration of sertraline, a selective serotonin reuptake inhibitor, was determined by a gas chromatograph with mass selective detection. The concentration of alprazolam, a triazolobenzodiazepine, was determined by high-performance liquid chromatography. The sertraline concentration was reported at 1.0 mg/L in peripheral blood, which is greater than previously reported in other postmortem cases in which death was attributed to a multiple drug overdose. The N-desmethylsertraline concentration was reported at 0.2 mg/L in peripheral blood, which is far less than in other postmortem cases and suggests acute intoxication in this case. The alprazolam concentration was reported at 33 microg/L in heart blood, which is within the therapeutic range. The cause of death was multiple drug intoxication following acute use of sertraline, the manner of death was suicide, and the mechanism of death is an unexplained drug interaction and/or toxicity.

Death from asthma associated with sertraline overdose

The authors report a case of a young woman for whom autopsy confirmed the cause of death to be due to an acute asthma attack. In addition, she had high serum levels of sertraline hydrochloride (Zoloft). The decedent had a recent prescription for sertraline filled, from which most of the pills were missing, suggesting a large consumption of medication. She was found dead at home, immersed in a bath. Autopsy revealed anatomic evidence of a severe recent asthma attack. Quantitative blood assay for sertraline was very high (620 ng/ml). Fatalities from sertraline alone are virtually nonexistent. The effects of sertraline on asthma, however, are not well-studied. Why the patient ingested so much sertraline is unclear. However, it is possible that, in a variant of the serotonin syndrome, a large dose of a selective serotonin reuptake inhibitor participated in precipitating an asthma attack or prevented her from being aware of the evolution of such an exacerbation. Additional observations in the future will be useful in assessing the role of this class of drugs in patients with asthma.

Urinary serotonin level is associated with serotonin syndrome after moclobemide, sertraline, and citalopram overdose

INTRODUCTION

Altered mental status, autonomic dysfunction, and neuromuscular abnormalities are a characteristic triad of serotonin syndrome. No laboratory tests confirm the diagnosis of serotonin syndrome.

CASE REPORT

A 35-year-old woman took moclobemide, sertraline, and citalopram in a suicide attempt. She was conscious with mild tachycardia, hypertension, and tachypnea one hour after ingestion. In the second hour after ingestion diaphoresis, mydriasis, horizontal nystagmus, trismus, hyperreflexia, clonus, and tremor appeared. She became agitated and unresponsive. In the third hour after ingestion she became comatose and hyperthermic. She was anesthetized, paralyzed, intubated, and ventilated for 24 hours. Serum moclobemide, sertraline, and citalopram levels were above therapeutic levels. The serum serotonin level was within normal limits and the urinary 5-hydroxyindoleacetic acid:creatinine ratio was below the average daily value. The urinary serotonin:creatinine ratio was increased on arrival (1 mg/g).

DISCUSSION AND CONCLUSION

The urinary serotonin level is increased in serotonin syndrome due to a monoamine oxidase inhibitor and selective serotonin-reuptake inhibitors overdose. It is possible that urinary serotonin concentration could be used as a biochemical marker of serotonin syndrome.

Massive sertraline overdose

Selective serotonin reuptake inhibitor medications are considered relatively safe even in overdose. We report a massive overdose of sertraline with the highest serum sertraline concentration reported to date. Clinical features of this patient were confusion, agitation, myoclonus, hyperreflexia, fever, and creatine kinase elevation. This case may represent serotonin syndrome caused by sertraline overdose alone.

[Postmortem distribution of sertraline and desmethylsertraline in a fatality]

Sertraline (CAS 79617-96-2) is a relatively safe medication for patients suffering from depression. Data reporting the postmortal distribution of sertraline and desmethylsertraline remain rare as well as reports of risks of side effects following ingestion of the drug. In a case of a young woman found dead in her flat sertraline and desmethylsertraline were identified and quantified in body fluids and tissues by gas chromatography/mass spectrometry and high performance liquid chromatography with diode array detection after alkaline extraction. Sertraline and its desmethyl metabolite were found in the peripheral blood in levels of 0.15 mg/l and 0.20 mg/l, concentrations in liver and bile were markedly higher. By exclusion of other reasons for death a lethal sertraline intoxication was decided. Sertraline is suggested to possess a low inherent toxicity, however, a risk of side-effects which may occur in single cases even under moderate dosages should be considered.

SSRI safety in overdose

BACKGROUND

The morbidity and mortality caused by tricyclic antidepressant (TCA) overdose are well recognized. Among newer antidepressants, the selective serotonin reuptake inhibitors (SSRIs) are thought to be safer in overdose. This study was designed to describe the signs, symptoms, and mortality associated with SSRI overdose.

METHOD

English-language articles identified through MEDLINE (1985 through 1997), and case reports from the American Association of Poison Control Centers (AAPCC) (1987 through 1996) and United States Food and Drug Administration (FDA) adverse event database (through 1997) that describe findings of fatal and nonfatal overdoses involving SSRIs alone or in combination with other ingestants were reviewed.

RESULTS

SSRI antidepressants are rarely fatal in overdose when taken alone. During the 10 years that SSRI antidepressants have been marketed, there have been remarkably few fatal overdoses reported in the literature or to the AAPCC or FDA involving ingestion only of an SSRI. Moderate overdoses (up to 30 times the common daily dose) are associated with minor or no symptoms, while ingestions of greater amounts typically result in drowsiness, tremor, nausea, and vomiting. At very high doses (> 75 times the common daily dose), more serious adverse events, including seizures, electrocardiogram (ECG) changes, and decreased consciousness may occur. SSRI overdoses in combination with alcohol or other drugs are associated with increased toxicity, and almost all fatalities involving SSRIs have involved coingestion of other substances.

CONCLUSION

The SSRI antidepressants are far safer than the TCAs in overdose. There is no apparent difference among SSRIs with respect to overdose safety.

[Consideration on serotoninergic syndrome based on a clinical situation ]

The diagnosis criteria for serotoninergic syndrome was first time proposed in 1991 by Sternbach, mixing clinical, biological and historical features. Drugs inducing serotonin accumulation by decreasing the synaptic recapture or increasing the serotoninergic transmission are responsible for the onset of this syndrome even in small amounts. We are describing a case of a young patient developing a comatose stage of serotoninergic syndrome as a result of Amitriptylinum and Sertralinum poisoning.