Fenfluramine-Phentermine (Fen-Phen) and Seizures: Evidence for an Association

Microdosing psychedelics and the risk of cardiac fibrosis and valvulopathy: Comparison to known cardiotoxins

Though microdosing psychedelics has become increasingly popular, its long-term effects on cardiac health remain unknown. Microdosing most commonly involves ingesting sub-threshold doses of lysergic acid diethylamide (LSD), psilocybin, or other psychedelic drugs 2-4 times a week for at least several weeks, but potentially months or years. Concerningly, both LSD and psilocybin share structural similarities with medications which raise the risk of cardiac fibrosis and valvulopathy when taken regularly, including methysergide, pergolide, and fenfluramine. 3,4-Methylenedioxymethamphetamine, which is also reportedly used for microdosing, is likewise associated with heart valve damage when taken chronically. In this review, we evaluate the evidence that microdosing LSD, psilocybin, and other psychedelics for several months or more could raise the risk of cardiac fibrosis. We discuss the relationship between drug-induced cardiac fibrosis and the 5-HT2B receptor, and we make recommendations for evaluating the safety of microdosing psychedelics in future studies.

Successful use of fenfluramine as an add-on treatment for Dravet syndrome

PURPOSE

Despite the development of new antiepileptic drugs, Dravet syndrome frequently remains therapy resistant and is a catastrophic epilepsy syndrome. Fenfluramine is an amphetamine-like drug that has been used in the past as a part of antiobesity treatments. Because of the possible cardiac adverse effects (valve thickening, pulmonary hypertension) associated with use of fenfluramine, it was withdrawn from the market in 2001. In Belgium, a Royal Decree permitted examination of the potential anticonvulsive effects of fenfluramine in a clinical trial consisting of a small group of patients diagnosed with Dravet syndrome.

METHODS

Herein, we report 12 patients, 7 female and 5 male, with a genetically proven (11 of 12) diagnosis of Dravet syndrome who received fenfluramine as add-on therapy.

KEY FINDINGS

Their ages at their last evaluation ranged from 3-35 years. The mean dosage of fenfluramine was 0.34 (0.12-0.90) mg/kg/day. Exposure duration to fenfluramine ranged from 1-19 years. Seven of the patients who were still receiving the fenfluramine treatment at the time of the last visit had been seizure-free for at least 1 year. In total, patients had been seizure-free for a mean of 6 (1-19) years. In seven patients, the fenfluramine treatment was interrupted once during the follow-up; seizures reappeared in three of the seizure-free patients. Subsequent reintroduction of fenfluramine controlled the seizures in these three patients again. Only two patients exhibited a mild thickening of one or two cardiac valves without clinical significance.

SIGNIFICANCE

Compared with a recent long-term follow-up series in which a maximum of 16% of patients with Dravet syndrome were seizure-free, our result of 70% of patients with Dravet syndrome remaining seizure-free is noteworthy. Given the limitations of this observational study, a larger prospective study should be undertaken to confirm these promising results.