Fenethylline (BAN, USAN), also spelled phenethylline and fenetylline (INN), and also known as amphetaminoethyltheophylline and amfetyline, is a codrug of amphetamine and theophylline which behaves as a prodrug to both of the aforementioned drugs. It is marketed for use as a psychostimulant under the brand names Captagon, Biocapton, and Fitton.
Fenethylline was first synthesized by the German Degussa AG in 1961 and used for around 25 years as a milder alternative to amphetamine and related compounds. Although there are no FDA-approved indications for fenethylline, it was used in the treatment of "hyperkinetic children" (what would now be referred to as Attention Deficit Hyperactivity Disorder) and, less commonly, for narcolepsy and depression. One of the main advantages of fenethylline was that it does not increase blood pressure to the same extent as an equivalent dose of amphetamine and so could be used in patients with cardiovascular conditions.
Fenethylline was considered to have fewer side effects and less potential for abuse than amphetamine. Nevertheless, fenethylline was listed in 1981 as a schedule I controlled substance in the US, and it became illegal in most countries in 1986 after being listed by the World Health Organization for international scheduling under the Convention on Psychotropic Substances, even though the actual incidence of fenethylline abuse was quite low.
Fenethylline is metabolized by the body to form two drugs, amphetamine (24.5% of oral dose) and theophylline (13.7% of oral dose), both of which are active stimulants. The physiological effects of fenethylline therefore result from a combination of these two compounds.
Abuse of fenethylline of the brand name Captagon is most common in Arab countries and counterfeit versions of the drug continue to be available despite its illegality.
Many of these counterfeit "Captagon" tablets actually contain other amphetamine derivatives that are easier to produce, but are pressed and stamped to look like Captagon pills. Some counterfeit Captagon pills analysed do contain fenethylline however, indicating that illicit production of this drug continues to take place.
Fenethylline is a popular drug in Western Asia, and is allegedly used by militant groups in Syria. It is manufactured locally in a cheap and simple process and it sells for between $5 and $20. According to some leaks, militant groups also export the drug in exchange for weapons and cash. According to Abdelelah Mohammed Al-Sharif, secretary general of the National Committee for Narcotics Control and assistant director of Anti-Drug and Preventative Affairs, 40% of the drug users who fall in the 12–22 age group in Saudi Arabia are addicted to fenethylline.
On 26 October 2015, a member of the Saudi royal family, Prince Abdel Mohsen Bin Walid Bin Abdulaziz, and four others were detained in Beirut on charges of drug trafficking after airport security discovered two tons of Captagon (fenethylline) pills and some cocaine on a private jet scheduled to depart for the Saudi capital of Riyadh. The following month, Agence France Press reported that the Turkish authorities had seized 2 tonnes of Captagon during raids in the Hatay region on the Syrian border. The pills, almost 11 million of them, had been produced in Syria and were being shipped to countries in the Arab states of the Persian Gulf.
On 31 December 2015 the Lebanese Army announced that it had discovered two large scale drug production workshops in the north of the country. Large quantities of Captagon pills were seized. Two days earlier three tons of Captagon and hashish were seized at Beirut airport. The drugs were concealed in school desks being exported to Egypt.
The drug is playing a role in the Syrian civil war. The production and sale of fenethylline generates large revenues which are likely used to fund weapons, as well as combatants on both sides using the stimulant to keep them fighting.
References to the drug were found on a mobile phone used by Mohamed Lahouaiej Bouhlel, a French-Tunisian who killed 84 civilians in Nice on Bastille Day, 2016.