What has been documented concerning clenbuterol, a beta-agonist, especially pertaining to its side-

Fråga: What has been documented concerning clenbuterol, a beta-agonist, especially pertaining to its side-effects?

(Background: Many athletes misuse this preparation and some have developed side-effects such as tremor, headache etc.)

Sammanfattning: Clenbuterol is a beta-2-agonist with general properties and side-effects similar to those of salbutamol. It is used as a bronchodilator in the management of asthma and obstructive lung disease. The doses used are 20 ug two or three times a day, with doses of up to 40 ug twice daily having occasionally been employed (1). The substance is not registered in Sweden but is available in Germany under the name of Spiropent and in Spain under the name of Ventolase.

Studies in animals indicate that clenbuterol and similar beta-agonists taken in large doses can provide a protein anabolic response that could be performance enhancing (2). Because of this, the drug has recently been used extensively among athletes. Illicit distribution and use of the drug in Sweden is well known. According to (3), doses, usually of two tablets 0.02 mg twice daily or sometimes even higher, are used until side-effects such as tachycardia, tremor or sleep disturbances appear. For general side-effects the spectrum is similar to those of salbutamol.

Svar: Se sammanfattning/konklusjon. 1 Martindale, The extra pharmacopoeia, 1993; 30:th ed: 1241 2 Muscling in on clenbuterol. Lancet 1992; 340: 403 (enclosed) 3 Personal communication Mats Garle, Huddinge Hospital, Doping Laboratory