Trazodone overdose

Gamble, D.E., and Peterson, L.G. (1986) Trazodone overdose four years of experience from voluntary reports. / Clin Psychiatry 47 544-546. 

Trazodone overdose carries a risk of myocardial irritation in patients with preexisting ventricular conduction abnormalities. 

Trazodone Hydrochloride Trazodone overdose causes severe toxic effects. These effects are severe if taken along with benzodiazepines or alcohol. Trazodone interacts with MAOIs, cardiovascular drugs, CNS depressants, and antiepileptics. 

In a 1980 review there were 68 cases of trazodone overdosage in amounts ranging up to 5 g (12 times the maximum therapeutic dose) (32). The predominant symptoms were drowsiness, dizziness, and rarely coma. There were no deaths in patients who took trazodone alone, and only two in those who took it in combination with other potentially lethal drugs. A brief review of data obtained from 46 cases of trazodone overdose reported to the National Poisons Information Service in London showed that 25 of the patients took overdoses of trazodone alone, while 21 took trazodone in combination with other drugs (33). This retrospective questionnaire study had inherent methodological flaws, but it did lend credence to the belief that trazodone is safe in overdose. 

Levenson JL. Prolonged QT interval after trazodone overdose. Am J Psychiatry 1999 156(6) 969-70. 

Myrick H, Markowitz JS, Henderson S. Priapism following trazodone overdose with cocaine use. Ann Clin Psychiatry 1998 10(2) 81-3. 

Root, I. Ohlson, G.B. Trazodone overdose report of two cases. JAnal.Toxicol., 1984, 8, 91—94... 

Histamine blockade is responsible for the sedation associated with trazodone. Furthermore, priapism and orthostatic hypotension are mediated by a-adrenergic antagonism. There have been over 200 case reports of priapism (Thompson et ah, 1990). Prevalence estimates of priapism suggest that 1/6000 men treated with trazodone will be affected. Other side effects include dry mouth, nausea, and vomiting. Because of trazodone s wide therapeutic window, it is relatively safe in overdosage. There are case reports of patients surviving intentional overdoses of up to 9 (Gamble and Peterson,... 

Trazodone can cause sedation and postural hypotension but is generally benign in acute overdoses as documented by a substantial number of overdoses occurring without death. 

Drug Trazodone (Desyrel) Mechanism (Amineselectivity) Slight inhibition of serotonin re uptake Advantages Sedating useful in agitation lower relative risk of overdose Disadvantages May cause orthostatic hypotension (similar to nefazodone) serious problems related to priapism may also occur in men... 

Tricyclics and the second- and third-generation agents differ mainly in the degree of sedation they produce (greatest with amitriptyline, doxepin, trazodone, and mirtazapine) and their antimuscarinic effects (greatest with amitriptyline and doxepin Table 30-3). SSRIs are generally free of sedative effects and remarkably safe in overdose. Combined with the ease of once-a-day dosing, these qualities may explain why they have become the most widely prescribed antidepressants. 

Trazodone is less cardiotoxic than tricyclic antidepressants, although it has rarely been reported to cause ventricular tachycardia. QT interval prolongation has been reported in overdose (34). 

A patient who took an overdose of trazodone (3 g) had sinus bradycardia (57 beats/minute) and a prolonged QTC interval (60 msec). The abnormal QTC interval gradually normalized over the next 3 days with supportive hospital treatment. 

A 44-year-old black man developed priapism 2 hours after having overdosed on 30-40 trazodone tablets 50 mg and 10 Tylenol No. 3 (paracetamol plus... 

Trazodone has structural similarities with TCAs but probably acts by antagonism of postsynaptic serotonin receptors and presynaptic a-adrenoceptors. It is an option for depressed patients where heavy sedation is required. Trazodone also has the advantages of lacking antimuscarinic effects and being relatively safe in overdose. Males should be warned of the possibility of priapism (painful penile erections), attributable to the drug s blockade of ttj-adrenoceptors. 

A 44-year-old black man developed priapism 2 hours after having overdosed on 30-40 trazodone tablets 50 mg and 10 Tylenol No. 3 (paracetamol plus codeine) tablets (162). Toxicology analysis was positive for cocaine and opiates. The priapism required detumescence twice, on initial presentation and then 6 hours later, and 8 hours after presentation he again developed painless priapism, which resolved spontaneously after 1.5 hours. 

Because this group as a whole engages in frequent suicidal acting out, it is advisable to treat borderline patients with medications that have been found to have a low degree of toxicity when taken in overdose. These include antipsychotics and the following antidepressants fluoxetine, paroxetine, bupropion (note above caution), trazodone, and sertraline. Most other antidepressants are quite toxic when taken in overdose. 

The most severe reactions reported with overdose of trazodone alone have been priapism, respiratory arrest, seizures, and ECG changes. 

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