About one fifth of patients who have had myocardial infarctions experience major depression. However, the cardiovascular side effects of some antidepressants have made physicians cautious about prescribing them to depressed patients with heart disease. Sheline and colleagues review the safety of selective serotonin reuptake inhibitors (SSRIs) in terms of cardiovascular side effects.
Antidepressants are known to cause conduction changes, as well as changes in heart rate, contractility and rhythm. Orthostatic hypotension is also a frequent problem. A MEDLINE search revealed that SSRIs may cause atrial fibrillation, atrial flutter and supraventricular tachycardia. In overdose, fluoxetine has been reported to cause sinus tachycardia, junctional rhythms and trigeminy. However, the total incidence of adverse cardiac effects was less than 0.0003 percent.
It seems that the main reason for adverse effects of SSRIs is the large number of drug interactions (see the accompanying table). Certain antihistamines are known to cause life-threatening arrhythmias when taken in conjunction with SSRIs. Other adverse effects include serotonergic syndrome, which can occur when SSRIs are taken in conjunction with monoamine oxidase inhibitors or tryptophan. It must be remembered that the long half-life of some SSRIs can cause interactions even after the SSRI has been discontinued.
The authors conclude that SSRIs are safe and do not have a high rate of cardiovascular adverse events. However, further study is needed to determine whether tricyclic antidepressants and SSRIs are equally efficacious in patients with cardiovascular disease. Overall, the risks of allowing depression to go untreated are probably higher than the risks of cardiovascular side effects associated with the use of antidepressants when proper precautions are taken.
Drug Metabolism Affected by Selective Serotonin Reuptake Inhibition
Antiarrhythmics Encainide Flecainide Lidocaine Mexiletine Propafenone Quinidine
Antihistamines Astemizole Terfenadine
Benzodiazepines Alprazolam Bromazepam Diazepam Midazolam Triazolam
Beta blockers Alprenolol Bufarolol Metoprolol Propranolol Timolol
Calcium channel blockers Diltiazem Felodipine Nifedipine Verapamil
Neuroleptics Clozapine Haloperidol Thioridazine Zuclopenthixol
Opiates Codeine Dextromethorphan Ethylmorphine
SSRIs Citalopram Fluoxetine Fluvoxamine Norfluoxetine Paroxetine Sertraline
Miscellaneous Amiflamine Brofaromine Caffeine Carbamazepine Cortisol Cyclosporin A Dexamethasone Erythromycin Ethinylestradiol 4-Hydro-amphetamine Hexobarbital Indoramin Omeprazole Paracetamol Perhexiline Phenformin Phenytoin Mephobarbital Proguanil Tacrine Tamoxifen Tolbutamide Tomoxetine Vinblastine Warfarin
SSRIs = selective serotonin reuptake inhibitors.
Reprinted with permission from Sheline YI, Freedland KE, Carney RM. How safe are serotonin reuptake inhibitors for depression in patients with coronary heart disease? Am J Med 1997;102:54-9.
Sheline YI, et al. How safe are serotonin reuptake inhibitors for depression in patients with coronary heart disease? Am J Med 1997;102:54-9.
COPYRIGHT 1997 American Academy of Family Physicians
COPYRIGHT 2004 Gale Group